Thomas Gleixner | 20c8ccb | 2019-06-04 10:11:32 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2009 Red Hat, Inc. |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 4 | */ |
| 5 | |
Andrew Morton | ae3a8c1 | 2014-06-04 16:06:58 -0700 | [diff] [blame] | 6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 7 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 8 | #include <linux/mm.h> |
| 9 | #include <linux/sched.h> |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 10 | #include <linux/sched/mm.h> |
Ingo Molnar | f7ccbae | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 11 | #include <linux/sched/coredump.h> |
Ingo Molnar | 6a3827d | 2017-02-08 18:51:31 +0100 | [diff] [blame] | 12 | #include <linux/sched/numa_balancing.h> |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 13 | #include <linux/highmem.h> |
| 14 | #include <linux/hugetlb.h> |
| 15 | #include <linux/mmu_notifier.h> |
| 16 | #include <linux/rmap.h> |
| 17 | #include <linux/swap.h> |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 18 | #include <linux/shrinker.h> |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 19 | #include <linux/mm_inline.h> |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 20 | #include <linux/swapops.h> |
Matthew Wilcox (Oracle) | fb5c202 | 2022-06-28 20:15:29 -0400 | [diff] [blame] | 21 | #include <linux/backing-dev.h> |
Matthew Wilcox | 4897c76 | 2015-09-08 14:58:45 -0700 | [diff] [blame] | 22 | #include <linux/dax.h> |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 23 | #include <linux/khugepaged.h> |
Andrea Arcangeli | 878aee7 | 2011-01-13 15:47:10 -0800 | [diff] [blame] | 24 | #include <linux/freezer.h> |
Dan Williams | f25748e3 | 2016-01-15 16:56:43 -0800 | [diff] [blame] | 25 | #include <linux/pfn_t.h> |
Andrea Arcangeli | a664b2d | 2011-01-13 15:47:17 -0800 | [diff] [blame] | 26 | #include <linux/mman.h> |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 27 | #include <linux/memremap.h> |
Ralf Baechle | 325adeb | 2012-10-15 13:44:56 +0200 | [diff] [blame] | 28 | #include <linux/pagemap.h> |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 29 | #include <linux/debugfs.h> |
Mel Gorman | 4daae3b | 2012-11-02 11:33:45 +0000 | [diff] [blame] | 30 | #include <linux/migrate.h> |
Sasha Levin | 43b5fbb | 2013-02-22 16:32:27 -0800 | [diff] [blame] | 31 | #include <linux/hashtable.h> |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 32 | #include <linux/userfaultfd_k.h> |
Vladimir Davydov | 33c3fc7 | 2015-09-09 15:35:45 -0700 | [diff] [blame] | 33 | #include <linux/page_idle.h> |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 34 | #include <linux/shmem_fs.h> |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 35 | #include <linux/oom.h> |
Anshuman Khandual | 98fa15f | 2019-03-05 15:42:58 -0800 | [diff] [blame] | 36 | #include <linux/numa.h> |
Vlastimil Babka | f7da677 | 2019-08-24 17:54:59 -0700 | [diff] [blame] | 37 | #include <linux/page_owner.h> |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 38 | #include <linux/sched/sysctl.h> |
Aneesh Kumar K.V | 467b171 | 2022-08-18 18:40:41 +0530 | [diff] [blame] | 39 | #include <linux/memory-tiers.h> |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 40 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 41 | #include <asm/tlb.h> |
| 42 | #include <asm/pgalloc.h> |
| 43 | #include "internal.h" |
NeilBrown | 014bb1d | 2022-05-09 18:20:47 -0700 | [diff] [blame] | 44 | #include "swap.h" |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 45 | |
Anshuman Khandual | 283fd6f | 2022-03-24 18:09:58 -0700 | [diff] [blame] | 46 | #define CREATE_TRACE_POINTS |
| 47 | #include <trace/events/thp.h> |
| 48 | |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 49 | /* |
Michael DeGuzis | b14d595 | 2017-05-17 15:19:21 -0400 | [diff] [blame] | 50 | * By default, transparent hugepage support is disabled in order to avoid |
| 51 | * risking an increased memory footprint for applications that are not |
| 52 | * guaranteed to benefit from it. When transparent hugepage support is |
| 53 | * enabled, it is for all mappings, and khugepaged scans all mappings. |
Jianguo Wu | 8bfa3f9 | 2013-11-12 15:07:16 -0800 | [diff] [blame] | 54 | * Defrag is invoked by khugepaged hugepage allocations and by page faults |
| 55 | * for all hugepage allocations. |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 56 | */ |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 57 | unsigned long transparent_hugepage_flags __read_mostly = |
Andrea Arcangeli | 13ece88 | 2011-01-13 15:47:07 -0800 | [diff] [blame] | 58 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 59 | (1<<TRANSPARENT_HUGEPAGE_FLAG)| |
Andrea Arcangeli | 13ece88 | 2011-01-13 15:47:07 -0800 | [diff] [blame] | 60 | #endif |
| 61 | #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE |
| 62 | (1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)| |
| 63 | #endif |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 64 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)| |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 65 | (1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)| |
| 66 | (1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 67 | |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 68 | static struct shrinker deferred_split_shrinker; |
Andrea Arcangeli | f000565 | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 69 | |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 70 | static atomic_t huge_zero_refcount; |
Wang, Yalin | 56873f4 | 2015-02-11 15:24:51 -0800 | [diff] [blame] | 71 | struct page *huge_zero_page __read_mostly; |
Hugh Dickins | 3b77e8c | 2021-06-15 18:23:49 -0700 | [diff] [blame] | 72 | unsigned long huge_zero_pfn __read_mostly = ~0UL; |
Kirill A. Shutemov | 4a6c129 | 2012-12-12 13:50:47 -0800 | [diff] [blame] | 73 | |
Zach O'Keefe | a7f4e6e | 2022-07-06 16:59:25 -0700 | [diff] [blame] | 74 | bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags, |
| 75 | bool smaps, bool in_pf, bool enforce_sysfs) |
Michal Hocko | 7635d9c | 2018-12-28 00:38:21 -0800 | [diff] [blame] | 76 | { |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 77 | if (!vma->vm_mm) /* vdso */ |
Yang Shi | c063066 | 2019-07-18 15:57:27 -0700 | [diff] [blame] | 78 | return false; |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 79 | |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 80 | /* |
| 81 | * Explicitly disabled through madvise or prctl, or some |
| 82 | * architectures may disable THP for some mappings, for |
| 83 | * example, s390 kvm. |
| 84 | * */ |
| 85 | if ((vm_flags & VM_NOHUGEPAGE) || |
| 86 | test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) |
| 87 | return false; |
| 88 | /* |
| 89 | * If the hardware/firmware marked hugepage support disabled. |
| 90 | */ |
Peter Xu | 3c556d2 | 2023-03-15 13:16:42 -0400 | [diff] [blame] | 91 | if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED)) |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 92 | return false; |
| 93 | |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 94 | /* khugepaged doesn't collapse DAX vma, but page fault is fine. */ |
| 95 | if (vma_is_dax(vma)) |
| 96 | return in_pf; |
| 97 | |
| 98 | /* |
| 99 | * Special VMA and hugetlb VMA. |
| 100 | * Must be checked after dax since some dax mappings may have |
| 101 | * VM_MIXEDMAP set. |
| 102 | */ |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 103 | if (vm_flags & VM_NO_KHUGEPAGED) |
| 104 | return false; |
| 105 | |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 106 | /* |
| 107 | * Check alignment for file vma and size for both file and anon vma. |
| 108 | * |
| 109 | * Skip the check for page fault. Huge fault does the check in fault |
| 110 | * handlers. And this check is not suitable for huge PUD fault. |
| 111 | */ |
| 112 | if (!in_pf && |
| 113 | !transhuge_vma_suitable(vma, (vma->vm_end - HPAGE_PMD_SIZE))) |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 114 | return false; |
| 115 | |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 116 | /* |
| 117 | * Enabled via shmem mount options or sysfs settings. |
| 118 | * Must be done before hugepage flags check since shmem has its |
| 119 | * own flags. |
| 120 | */ |
| 121 | if (!in_pf && shmem_file(vma->vm_file)) |
David Stevens | 2cf1338 | 2023-01-13 11:30:11 +0900 | [diff] [blame] | 122 | return shmem_is_huge(file_inode(vma->vm_file), vma->vm_pgoff, |
| 123 | !enforce_sysfs, vma->vm_mm, vm_flags); |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 124 | |
Zach O'Keefe | a7f4e6e | 2022-07-06 16:59:25 -0700 | [diff] [blame] | 125 | /* Enforce sysfs THP requirements as necessary */ |
| 126 | if (enforce_sysfs && |
| 127 | (!hugepage_flags_enabled() || (!(vm_flags & VM_HUGEPAGE) && |
| 128 | !hugepage_flags_always()))) |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 129 | return false; |
| 130 | |
| 131 | /* Only regular file is valid */ |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 132 | if (!in_pf && file_thp_enabled(vma)) |
Yang Shi | 78d12c1 | 2022-05-19 14:08:49 -0700 | [diff] [blame] | 133 | return true; |
Michal Hocko | 7635d9c | 2018-12-28 00:38:21 -0800 | [diff] [blame] | 134 | |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 135 | if (!vma_is_anonymous(vma)) |
| 136 | return false; |
| 137 | |
| 138 | if (vma_is_temporary_stack(vma)) |
| 139 | return false; |
| 140 | |
| 141 | /* |
| 142 | * THPeligible bit of smaps should show 1 for proper VMAs even |
| 143 | * though anon_vma is not initialized yet. |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 144 | * |
| 145 | * Allow page fault since anon_vma may be not initialized until |
| 146 | * the first page fault. |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 147 | */ |
| 148 | if (!vma->anon_vma) |
Yang Shi | 7da4e2c | 2022-06-16 10:48:38 -0700 | [diff] [blame] | 149 | return (smaps || in_pf); |
Yang Shi | 9fec516 | 2022-06-16 10:48:37 -0700 | [diff] [blame] | 150 | |
| 151 | return true; |
Michal Hocko | 7635d9c | 2018-12-28 00:38:21 -0800 | [diff] [blame] | 152 | } |
| 153 | |
Miaohe Lin | aaa9705 | 2021-05-04 18:33:55 -0700 | [diff] [blame] | 154 | static bool get_huge_zero_page(void) |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 155 | { |
| 156 | struct page *zero_page; |
| 157 | retry: |
| 158 | if (likely(atomic_inc_not_zero(&huge_zero_refcount))) |
Miaohe Lin | aaa9705 | 2021-05-04 18:33:55 -0700 | [diff] [blame] | 159 | return true; |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 160 | |
| 161 | zero_page = alloc_pages((GFP_TRANSHUGE | __GFP_ZERO) & ~__GFP_MOVABLE, |
| 162 | HPAGE_PMD_ORDER); |
Kirill A. Shutemov | d8a8e1f | 2012-12-12 13:51:09 -0800 | [diff] [blame] | 163 | if (!zero_page) { |
| 164 | count_vm_event(THP_ZERO_PAGE_ALLOC_FAILED); |
Miaohe Lin | aaa9705 | 2021-05-04 18:33:55 -0700 | [diff] [blame] | 165 | return false; |
Kirill A. Shutemov | d8a8e1f | 2012-12-12 13:51:09 -0800 | [diff] [blame] | 166 | } |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 167 | preempt_disable(); |
Kirill A. Shutemov | 5918d10 | 2013-04-29 15:08:44 -0700 | [diff] [blame] | 168 | if (cmpxchg(&huge_zero_page, NULL, zero_page)) { |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 169 | preempt_enable(); |
Yu Zhao | 5ddacbe | 2014-10-29 14:50:26 -0700 | [diff] [blame] | 170 | __free_pages(zero_page, compound_order(zero_page)); |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 171 | goto retry; |
| 172 | } |
Hugh Dickins | 3b77e8c | 2021-06-15 18:23:49 -0700 | [diff] [blame] | 173 | WRITE_ONCE(huge_zero_pfn, page_to_pfn(zero_page)); |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 174 | |
| 175 | /* We take additional reference here. It will be put back by shrinker */ |
| 176 | atomic_set(&huge_zero_refcount, 2); |
| 177 | preempt_enable(); |
Liu Shixin | f498150 | 2022-09-09 10:16:53 +0800 | [diff] [blame] | 178 | count_vm_event(THP_ZERO_PAGE_ALLOC); |
Miaohe Lin | aaa9705 | 2021-05-04 18:33:55 -0700 | [diff] [blame] | 179 | return true; |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 180 | } |
| 181 | |
Aaron Lu | 6fcb52a | 2016-10-07 17:00:08 -0700 | [diff] [blame] | 182 | static void put_huge_zero_page(void) |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 183 | { |
| 184 | /* |
| 185 | * Counter should never go to zero here. Only shrinker can put |
| 186 | * last reference. |
| 187 | */ |
| 188 | BUG_ON(atomic_dec_and_test(&huge_zero_refcount)); |
| 189 | } |
| 190 | |
Aaron Lu | 6fcb52a | 2016-10-07 17:00:08 -0700 | [diff] [blame] | 191 | struct page *mm_get_huge_zero_page(struct mm_struct *mm) |
| 192 | { |
| 193 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) |
| 194 | return READ_ONCE(huge_zero_page); |
| 195 | |
| 196 | if (!get_huge_zero_page()) |
| 197 | return NULL; |
| 198 | |
| 199 | if (test_and_set_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) |
| 200 | put_huge_zero_page(); |
| 201 | |
| 202 | return READ_ONCE(huge_zero_page); |
| 203 | } |
| 204 | |
| 205 | void mm_put_huge_zero_page(struct mm_struct *mm) |
| 206 | { |
| 207 | if (test_bit(MMF_HUGE_ZERO_PAGE, &mm->flags)) |
| 208 | put_huge_zero_page(); |
| 209 | } |
| 210 | |
Glauber Costa | 4889646 | 2013-08-28 10:18:15 +1000 | [diff] [blame] | 211 | static unsigned long shrink_huge_zero_page_count(struct shrinker *shrink, |
| 212 | struct shrink_control *sc) |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 213 | { |
Glauber Costa | 4889646 | 2013-08-28 10:18:15 +1000 | [diff] [blame] | 214 | /* we can free zero page only if last reference remains */ |
| 215 | return atomic_read(&huge_zero_refcount) == 1 ? HPAGE_PMD_NR : 0; |
| 216 | } |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 217 | |
Glauber Costa | 4889646 | 2013-08-28 10:18:15 +1000 | [diff] [blame] | 218 | static unsigned long shrink_huge_zero_page_scan(struct shrinker *shrink, |
| 219 | struct shrink_control *sc) |
| 220 | { |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 221 | if (atomic_cmpxchg(&huge_zero_refcount, 1, 0) == 1) { |
Kirill A. Shutemov | 5918d10 | 2013-04-29 15:08:44 -0700 | [diff] [blame] | 222 | struct page *zero_page = xchg(&huge_zero_page, NULL); |
| 223 | BUG_ON(zero_page == NULL); |
Hugh Dickins | 3b77e8c | 2021-06-15 18:23:49 -0700 | [diff] [blame] | 224 | WRITE_ONCE(huge_zero_pfn, ~0UL); |
Yu Zhao | 5ddacbe | 2014-10-29 14:50:26 -0700 | [diff] [blame] | 225 | __free_pages(zero_page, compound_order(zero_page)); |
Glauber Costa | 4889646 | 2013-08-28 10:18:15 +1000 | [diff] [blame] | 226 | return HPAGE_PMD_NR; |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 227 | } |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | static struct shrinker huge_zero_page_shrinker = { |
Glauber Costa | 4889646 | 2013-08-28 10:18:15 +1000 | [diff] [blame] | 233 | .count_objects = shrink_huge_zero_page_count, |
| 234 | .scan_objects = shrink_huge_zero_page_scan, |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 235 | .seeks = DEFAULT_SEEKS, |
| 236 | }; |
| 237 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 238 | #ifdef CONFIG_SYSFS |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 239 | static ssize_t enabled_show(struct kobject *kobj, |
| 240 | struct kobj_attribute *attr, char *buf) |
| 241 | { |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 242 | const char *output; |
| 243 | |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 244 | if (test_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags)) |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 245 | output = "[always] madvise never"; |
| 246 | else if (test_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, |
| 247 | &transparent_hugepage_flags)) |
| 248 | output = "always [madvise] never"; |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 249 | else |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 250 | output = "always madvise [never]"; |
| 251 | |
| 252 | return sysfs_emit(buf, "%s\n", output); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 253 | } |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 254 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 255 | static ssize_t enabled_store(struct kobject *kobj, |
| 256 | struct kobj_attribute *attr, |
| 257 | const char *buf, size_t count) |
| 258 | { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 259 | ssize_t ret = count; |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 260 | |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 261 | if (sysfs_streq(buf, "always")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 262 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 263 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 264 | } else if (sysfs_streq(buf, "madvise")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 265 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
| 266 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 267 | } else if (sysfs_streq(buf, "never")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 268 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); |
| 269 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 270 | } else |
| 271 | ret = -EINVAL; |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 272 | |
| 273 | if (ret > 0) { |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 274 | int err = start_stop_khugepaged(); |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 275 | if (err) |
| 276 | ret = err; |
| 277 | } |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 278 | return ret; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 279 | } |
Miaohe Lin | 37139bb | 2022-07-04 21:21:53 +0800 | [diff] [blame] | 280 | |
| 281 | static struct kobj_attribute enabled_attr = __ATTR_RW(enabled); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 282 | |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 283 | ssize_t single_hugepage_flag_show(struct kobject *kobj, |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 284 | struct kobj_attribute *attr, char *buf, |
| 285 | enum transparent_hugepage_flag flag) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 286 | { |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 287 | return sysfs_emit(buf, "%d\n", |
| 288 | !!test_bit(flag, &transparent_hugepage_flags)); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 289 | } |
Ben Hutchings | e27e615 | 2011-04-14 15:22:21 -0700 | [diff] [blame] | 290 | |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 291 | ssize_t single_hugepage_flag_store(struct kobject *kobj, |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 292 | struct kobj_attribute *attr, |
| 293 | const char *buf, size_t count, |
| 294 | enum transparent_hugepage_flag flag) |
| 295 | { |
Ben Hutchings | e27e615 | 2011-04-14 15:22:21 -0700 | [diff] [blame] | 296 | unsigned long value; |
| 297 | int ret; |
| 298 | |
| 299 | ret = kstrtoul(buf, 10, &value); |
| 300 | if (ret < 0) |
| 301 | return ret; |
| 302 | if (value > 1) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 303 | return -EINVAL; |
| 304 | |
Ben Hutchings | e27e615 | 2011-04-14 15:22:21 -0700 | [diff] [blame] | 305 | if (value) |
| 306 | set_bit(flag, &transparent_hugepage_flags); |
| 307 | else |
| 308 | clear_bit(flag, &transparent_hugepage_flags); |
| 309 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 310 | return count; |
| 311 | } |
| 312 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 313 | static ssize_t defrag_show(struct kobject *kobj, |
| 314 | struct kobj_attribute *attr, char *buf) |
| 315 | { |
Joe Perches | bfb0ffe | 2020-12-14 19:14:46 -0800 | [diff] [blame] | 316 | const char *output; |
| 317 | |
| 318 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, |
| 319 | &transparent_hugepage_flags)) |
| 320 | output = "[always] defer defer+madvise madvise never"; |
| 321 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, |
| 322 | &transparent_hugepage_flags)) |
| 323 | output = "always [defer] defer+madvise madvise never"; |
| 324 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, |
| 325 | &transparent_hugepage_flags)) |
| 326 | output = "always defer [defer+madvise] madvise never"; |
| 327 | else if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, |
| 328 | &transparent_hugepage_flags)) |
| 329 | output = "always defer defer+madvise [madvise] never"; |
| 330 | else |
| 331 | output = "always defer defer+madvise madvise [never]"; |
| 332 | |
| 333 | return sysfs_emit(buf, "%s\n", output); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 334 | } |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 335 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 336 | static ssize_t defrag_store(struct kobject *kobj, |
| 337 | struct kobj_attribute *attr, |
| 338 | const char *buf, size_t count) |
| 339 | { |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 340 | if (sysfs_streq(buf, "always")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 341 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
| 342 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); |
| 343 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 344 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 345 | } else if (sysfs_streq(buf, "defer+madvise")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 346 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
| 347 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
| 348 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 349 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 350 | } else if (sysfs_streq(buf, "defer")) { |
David Rientjes | 4fad7fb | 2017-04-07 16:04:54 -0700 | [diff] [blame] | 351 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
| 352 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); |
| 353 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 354 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 355 | } else if (sysfs_streq(buf, "madvise")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 356 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
| 357 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
| 358 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); |
| 359 | set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); |
David Rientjes | f42f255 | 2020-01-30 22:14:48 -0800 | [diff] [blame] | 360 | } else if (sysfs_streq(buf, "never")) { |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 361 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); |
| 362 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); |
| 363 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); |
| 364 | clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); |
| 365 | } else |
| 366 | return -EINVAL; |
| 367 | |
| 368 | return count; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 369 | } |
Miaohe Lin | 37139bb | 2022-07-04 21:21:53 +0800 | [diff] [blame] | 370 | static struct kobj_attribute defrag_attr = __ATTR_RW(defrag); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 371 | |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 372 | static ssize_t use_zero_page_show(struct kobject *kobj, |
Joe Perches | ae7a927 | 2020-12-14 19:14:42 -0800 | [diff] [blame] | 373 | struct kobj_attribute *attr, char *buf) |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 374 | { |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 375 | return single_hugepage_flag_show(kobj, attr, buf, |
Joe Perches | ae7a927 | 2020-12-14 19:14:42 -0800 | [diff] [blame] | 376 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 377 | } |
| 378 | static ssize_t use_zero_page_store(struct kobject *kobj, |
| 379 | struct kobj_attribute *attr, const char *buf, size_t count) |
| 380 | { |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 381 | return single_hugepage_flag_store(kobj, attr, buf, count, |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 382 | TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG); |
| 383 | } |
Miaohe Lin | 37139bb | 2022-07-04 21:21:53 +0800 | [diff] [blame] | 384 | static struct kobj_attribute use_zero_page_attr = __ATTR_RW(use_zero_page); |
Hugh Dickins | 49920d2 | 2016-12-12 16:44:50 -0800 | [diff] [blame] | 385 | |
| 386 | static ssize_t hpage_pmd_size_show(struct kobject *kobj, |
Joe Perches | ae7a927 | 2020-12-14 19:14:42 -0800 | [diff] [blame] | 387 | struct kobj_attribute *attr, char *buf) |
Hugh Dickins | 49920d2 | 2016-12-12 16:44:50 -0800 | [diff] [blame] | 388 | { |
Joe Perches | ae7a927 | 2020-12-14 19:14:42 -0800 | [diff] [blame] | 389 | return sysfs_emit(buf, "%lu\n", HPAGE_PMD_SIZE); |
Hugh Dickins | 49920d2 | 2016-12-12 16:44:50 -0800 | [diff] [blame] | 390 | } |
| 391 | static struct kobj_attribute hpage_pmd_size_attr = |
| 392 | __ATTR_RO(hpage_pmd_size); |
| 393 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 394 | static struct attribute *hugepage_attr[] = { |
| 395 | &enabled_attr.attr, |
| 396 | &defrag_attr.attr, |
Kirill A. Shutemov | 79da540 | 2012-12-12 13:51:12 -0800 | [diff] [blame] | 397 | &use_zero_page_attr.attr, |
Hugh Dickins | 49920d2 | 2016-12-12 16:44:50 -0800 | [diff] [blame] | 398 | &hpage_pmd_size_attr.attr, |
Matthew Wilcox (Oracle) | 396bcc5 | 2020-04-06 20:04:35 -0700 | [diff] [blame] | 399 | #ifdef CONFIG_SHMEM |
Kirill A. Shutemov | 5a6e75f | 2016-07-26 15:26:13 -0700 | [diff] [blame] | 400 | &shmem_enabled_attr.attr, |
| 401 | #endif |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 402 | NULL, |
| 403 | }; |
| 404 | |
Arvind Yadav | 8aa95a2 | 2017-09-06 16:22:03 -0700 | [diff] [blame] | 405 | static const struct attribute_group hugepage_attr_group = { |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 406 | .attrs = hugepage_attr, |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 407 | }; |
| 408 | |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 409 | static int __init hugepage_init_sysfs(struct kobject **hugepage_kobj) |
| 410 | { |
| 411 | int err; |
| 412 | |
| 413 | *hugepage_kobj = kobject_create_and_add("transparent_hugepage", mm_kobj); |
| 414 | if (unlikely(!*hugepage_kobj)) { |
Andrew Morton | ae3a8c1 | 2014-06-04 16:06:58 -0700 | [diff] [blame] | 415 | pr_err("failed to create transparent hugepage kobject\n"); |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 416 | return -ENOMEM; |
| 417 | } |
| 418 | |
| 419 | err = sysfs_create_group(*hugepage_kobj, &hugepage_attr_group); |
| 420 | if (err) { |
Andrew Morton | ae3a8c1 | 2014-06-04 16:06:58 -0700 | [diff] [blame] | 421 | pr_err("failed to register transparent hugepage group\n"); |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 422 | goto delete_obj; |
| 423 | } |
| 424 | |
| 425 | err = sysfs_create_group(*hugepage_kobj, &khugepaged_attr_group); |
| 426 | if (err) { |
Andrew Morton | ae3a8c1 | 2014-06-04 16:06:58 -0700 | [diff] [blame] | 427 | pr_err("failed to register transparent hugepage group\n"); |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 428 | goto remove_hp_group; |
| 429 | } |
| 430 | |
| 431 | return 0; |
| 432 | |
| 433 | remove_hp_group: |
| 434 | sysfs_remove_group(*hugepage_kobj, &hugepage_attr_group); |
| 435 | delete_obj: |
| 436 | kobject_put(*hugepage_kobj); |
| 437 | return err; |
| 438 | } |
| 439 | |
| 440 | static void __init hugepage_exit_sysfs(struct kobject *hugepage_kobj) |
| 441 | { |
| 442 | sysfs_remove_group(hugepage_kobj, &khugepaged_attr_group); |
| 443 | sysfs_remove_group(hugepage_kobj, &hugepage_attr_group); |
| 444 | kobject_put(hugepage_kobj); |
| 445 | } |
| 446 | #else |
| 447 | static inline int hugepage_init_sysfs(struct kobject **hugepage_kobj) |
| 448 | { |
| 449 | return 0; |
| 450 | } |
| 451 | |
| 452 | static inline void hugepage_exit_sysfs(struct kobject *hugepage_kobj) |
| 453 | { |
| 454 | } |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 455 | #endif /* CONFIG_SYSFS */ |
| 456 | |
| 457 | static int __init hugepage_init(void) |
| 458 | { |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 459 | int err; |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 460 | struct kobject *hugepage_kobj; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 461 | |
Andrea Arcangeli | 4b7167b | 2011-01-13 15:47:09 -0800 | [diff] [blame] | 462 | if (!has_transparent_hugepage()) { |
Peter Xu | 3c556d2 | 2023-03-15 13:16:42 -0400 | [diff] [blame] | 463 | transparent_hugepage_flags = 1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED; |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 464 | return -EINVAL; |
Andrea Arcangeli | 4b7167b | 2011-01-13 15:47:09 -0800 | [diff] [blame] | 465 | } |
| 466 | |
Kirill A. Shutemov | ff20c2e | 2016-03-01 09:45:14 +0530 | [diff] [blame] | 467 | /* |
| 468 | * hugepages can't be allocated by the buddy allocator |
| 469 | */ |
Kirill A. Shutemov | 23baf83 | 2023-03-15 14:31:33 +0300 | [diff] [blame] | 470 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER > MAX_ORDER); |
Kirill A. Shutemov | ff20c2e | 2016-03-01 09:45:14 +0530 | [diff] [blame] | 471 | /* |
| 472 | * we use page->mapping and page->index in second tail page |
| 473 | * as list_head: assuming THP order >= 2 |
| 474 | */ |
| 475 | MAYBE_BUILD_BUG_ON(HPAGE_PMD_ORDER < 2); |
| 476 | |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 477 | err = hugepage_init_sysfs(&hugepage_kobj); |
| 478 | if (err) |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 479 | goto err_sysfs; |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 480 | |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 481 | err = khugepaged_init(); |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 482 | if (err) |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 483 | goto err_slab; |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 484 | |
Roman Gushchin | e33c267 | 2022-05-31 20:22:24 -0700 | [diff] [blame] | 485 | err = register_shrinker(&huge_zero_page_shrinker, "thp-zero"); |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 486 | if (err) |
| 487 | goto err_hzp_shrinker; |
Roman Gushchin | e33c267 | 2022-05-31 20:22:24 -0700 | [diff] [blame] | 488 | err = register_shrinker(&deferred_split_shrinker, "thp-deferred_split"); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 489 | if (err) |
| 490 | goto err_split_shrinker; |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 491 | |
Rik van Riel | 97562cd | 2011-01-13 15:47:12 -0800 | [diff] [blame] | 492 | /* |
| 493 | * By default disable transparent hugepages on smaller systems, |
| 494 | * where the extra memory used could hurt more than TLB overhead |
| 495 | * is likely to save. The admin can still enable it through /sys. |
| 496 | */ |
Arun KS | ca79b0c | 2018-12-28 00:34:29 -0800 | [diff] [blame] | 497 | if (totalram_pages() < (512 << (20 - PAGE_SHIFT))) { |
Rik van Riel | 97562cd | 2011-01-13 15:47:12 -0800 | [diff] [blame] | 498 | transparent_hugepage_flags = 0; |
Kirill A. Shutemov | 79553da293 | 2015-04-15 16:14:56 -0700 | [diff] [blame] | 499 | return 0; |
| 500 | } |
Rik van Riel | 97562cd | 2011-01-13 15:47:12 -0800 | [diff] [blame] | 501 | |
Kirill A. Shutemov | 79553da293 | 2015-04-15 16:14:56 -0700 | [diff] [blame] | 502 | err = start_stop_khugepaged(); |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 503 | if (err) |
| 504 | goto err_khugepaged; |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 505 | |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 506 | return 0; |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 507 | err_khugepaged: |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 508 | unregister_shrinker(&deferred_split_shrinker); |
| 509 | err_split_shrinker: |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 510 | unregister_shrinker(&huge_zero_page_shrinker); |
| 511 | err_hzp_shrinker: |
Kirill A. Shutemov | b46e756 | 2016-07-26 15:26:24 -0700 | [diff] [blame] | 512 | khugepaged_destroy(); |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 513 | err_slab: |
Shaohua Li | 569e559 | 2012-01-12 17:19:11 -0800 | [diff] [blame] | 514 | hugepage_exit_sysfs(hugepage_kobj); |
Kirill A. Shutemov | 65ebb64 | 2015-04-15 16:14:20 -0700 | [diff] [blame] | 515 | err_sysfs: |
Andrea Arcangeli | ba76149 | 2011-01-13 15:46:58 -0800 | [diff] [blame] | 516 | return err; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 517 | } |
Paul Gortmaker | a64fb3c | 2014-01-23 15:53:30 -0800 | [diff] [blame] | 518 | subsys_initcall(hugepage_init); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 519 | |
| 520 | static int __init setup_transparent_hugepage(char *str) |
| 521 | { |
| 522 | int ret = 0; |
| 523 | if (!str) |
| 524 | goto out; |
| 525 | if (!strcmp(str, "always")) { |
| 526 | set_bit(TRANSPARENT_HUGEPAGE_FLAG, |
| 527 | &transparent_hugepage_flags); |
| 528 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, |
| 529 | &transparent_hugepage_flags); |
| 530 | ret = 1; |
| 531 | } else if (!strcmp(str, "madvise")) { |
| 532 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, |
| 533 | &transparent_hugepage_flags); |
| 534 | set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, |
| 535 | &transparent_hugepage_flags); |
| 536 | ret = 1; |
| 537 | } else if (!strcmp(str, "never")) { |
| 538 | clear_bit(TRANSPARENT_HUGEPAGE_FLAG, |
| 539 | &transparent_hugepage_flags); |
| 540 | clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, |
| 541 | &transparent_hugepage_flags); |
| 542 | ret = 1; |
| 543 | } |
| 544 | out: |
| 545 | if (!ret) |
Andrew Morton | ae3a8c1 | 2014-06-04 16:06:58 -0700 | [diff] [blame] | 546 | pr_warn("transparent_hugepage= cannot parse, ignored\n"); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 547 | return ret; |
| 548 | } |
| 549 | __setup("transparent_hugepage=", setup_transparent_hugepage); |
| 550 | |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 551 | pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 552 | { |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 553 | if (likely(vma->vm_flags & VM_WRITE)) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 554 | pmd = pmd_mkwrite(pmd); |
| 555 | return pmd; |
| 556 | } |
| 557 | |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 558 | #ifdef CONFIG_MEMCG |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 559 | static inline |
| 560 | struct deferred_split *get_deferred_split_queue(struct folio *folio) |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 561 | { |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 562 | struct mem_cgroup *memcg = folio_memcg(folio); |
| 563 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 564 | |
| 565 | if (memcg) |
| 566 | return &memcg->deferred_split_queue; |
| 567 | else |
| 568 | return &pgdat->deferred_split_queue; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 569 | } |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 570 | #else |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 571 | static inline |
| 572 | struct deferred_split *get_deferred_split_queue(struct folio *folio) |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 573 | { |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 574 | struct pglist_data *pgdat = NODE_DATA(folio_nid(folio)); |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 575 | |
| 576 | return &pgdat->deferred_split_queue; |
| 577 | } |
| 578 | #endif |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 579 | |
| 580 | void prep_transhuge_page(struct page *page) |
| 581 | { |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 582 | struct folio *folio = (struct folio *)page; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 583 | |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 584 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
| 585 | INIT_LIST_HEAD(&folio->_deferred_list); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 586 | set_compound_page_dtor(page, TRANSHUGE_PAGE_DTOR); |
| 587 | } |
| 588 | |
Miaohe Lin | 562beb7 | 2022-03-24 18:13:27 -0700 | [diff] [blame] | 589 | static inline bool is_transparent_hugepage(struct page *page) |
Sean Christopherson | 005ba37 | 2020-01-08 12:24:36 -0800 | [diff] [blame] | 590 | { |
Matthew Wilcox (Oracle) | f04029f | 2023-01-11 14:29:05 +0000 | [diff] [blame] | 591 | struct folio *folio; |
| 592 | |
Sean Christopherson | 005ba37 | 2020-01-08 12:24:36 -0800 | [diff] [blame] | 593 | if (!PageCompound(page)) |
Zou Wei | fa1f68c | 2020-06-04 16:49:46 -0700 | [diff] [blame] | 594 | return false; |
Sean Christopherson | 005ba37 | 2020-01-08 12:24:36 -0800 | [diff] [blame] | 595 | |
Matthew Wilcox (Oracle) | f04029f | 2023-01-11 14:29:05 +0000 | [diff] [blame] | 596 | folio = page_folio(page); |
| 597 | return is_huge_zero_page(&folio->page) || |
| 598 | folio->_folio_dtor == TRANSHUGE_PAGE_DTOR; |
Sean Christopherson | 005ba37 | 2020-01-08 12:24:36 -0800 | [diff] [blame] | 599 | } |
Sean Christopherson | 005ba37 | 2020-01-08 12:24:36 -0800 | [diff] [blame] | 600 | |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 601 | static unsigned long __thp_get_unmapped_area(struct file *filp, |
| 602 | unsigned long addr, unsigned long len, |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 603 | loff_t off, unsigned long flags, unsigned long size) |
| 604 | { |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 605 | loff_t off_end = off + len; |
| 606 | loff_t off_align = round_up(off, size); |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 607 | unsigned long len_pad, ret; |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 608 | |
| 609 | if (off_end <= off_align || (off_end - off_align) < size) |
| 610 | return 0; |
| 611 | |
| 612 | len_pad = len + size; |
| 613 | if (len_pad < len || (off + len_pad) < off) |
| 614 | return 0; |
| 615 | |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 616 | ret = current->mm->get_unmapped_area(filp, addr, len_pad, |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 617 | off >> PAGE_SHIFT, flags); |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 618 | |
| 619 | /* |
| 620 | * The failure might be due to length padding. The caller will retry |
| 621 | * without the padding. |
| 622 | */ |
| 623 | if (IS_ERR_VALUE(ret)) |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 624 | return 0; |
| 625 | |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 626 | /* |
| 627 | * Do not try to align to THP boundary if allocation at the address |
| 628 | * hint succeeds. |
| 629 | */ |
| 630 | if (ret == addr) |
| 631 | return addr; |
| 632 | |
| 633 | ret += (off - ret) & (size - 1); |
| 634 | return ret; |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 635 | } |
| 636 | |
| 637 | unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr, |
| 638 | unsigned long len, unsigned long pgoff, unsigned long flags) |
| 639 | { |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 640 | unsigned long ret; |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 641 | loff_t off = (loff_t)pgoff << PAGE_SHIFT; |
| 642 | |
Kirill A. Shutemov | 97d3d0f | 2020-01-13 16:29:10 -0800 | [diff] [blame] | 643 | ret = __thp_get_unmapped_area(filp, addr, len, off, flags, PMD_SIZE); |
| 644 | if (ret) |
| 645 | return ret; |
William Kucharski | 1854bc6 | 2019-09-22 08:43:15 -0400 | [diff] [blame] | 646 | |
Toshi Kani | 74d2fad | 2016-10-07 16:59:56 -0700 | [diff] [blame] | 647 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); |
| 648 | } |
| 649 | EXPORT_SYMBOL_GPL(thp_get_unmapped_area); |
| 650 | |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 651 | static vm_fault_t __do_huge_pmd_anonymous_page(struct vm_fault *vmf, |
| 652 | struct page *page, gfp_t gfp) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 653 | { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 654 | struct vm_area_struct *vma = vmf->vma; |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 655 | struct folio *folio = page_folio(page); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 656 | pgtable_t pgtable; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 657 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 658 | vm_fault_t ret = 0; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 659 | |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 660 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 661 | |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 662 | if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { |
| 663 | folio_put(folio); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 664 | count_vm_event(THP_FAULT_FALLBACK); |
David Rientjes | 85b9f46 | 2020-04-06 20:04:28 -0700 | [diff] [blame] | 665 | count_vm_event(THP_FAULT_FALLBACK_CHARGE); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 666 | return VM_FAULT_FALLBACK; |
| 667 | } |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 668 | folio_throttle_swaprate(folio, gfp); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 669 | |
Joel Fernandes (Google) | 4cf5892 | 2019-01-03 15:28:34 -0800 | [diff] [blame] | 670 | pgtable = pte_alloc_one(vma->vm_mm); |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 671 | if (unlikely(!pgtable)) { |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 672 | ret = VM_FAULT_OOM; |
| 673 | goto release; |
Johannes Weiner | 00501b5 | 2014-08-08 14:19:20 -0700 | [diff] [blame] | 674 | } |
| 675 | |
Huang Ying | c79b57e | 2017-09-06 16:25:04 -0700 | [diff] [blame] | 676 | clear_huge_page(page, vmf->address, HPAGE_PMD_NR); |
Minchan Kim | 52f3762 | 2013-04-29 15:08:15 -0700 | [diff] [blame] | 677 | /* |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 678 | * The memory barrier inside __folio_mark_uptodate makes sure that |
Minchan Kim | 52f3762 | 2013-04-29 15:08:15 -0700 | [diff] [blame] | 679 | * clear_huge_page writes become visible before the set_pmd_at() |
| 680 | * write. |
| 681 | */ |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 682 | __folio_mark_uptodate(folio); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 683 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 684 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
| 685 | if (unlikely(!pmd_none(*vmf->pmd))) { |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 686 | goto unlock_release; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 687 | } else { |
| 688 | pmd_t entry; |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 689 | |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 690 | ret = check_stable_address_space(vma->vm_mm); |
| 691 | if (ret) |
| 692 | goto unlock_release; |
| 693 | |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 694 | /* Deliver the page fault to userland */ |
| 695 | if (userfaultfd_missing(vma)) { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 696 | spin_unlock(vmf->ptl); |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 697 | folio_put(folio); |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 698 | pte_free(vma->vm_mm, pgtable); |
Miaohe Lin | 8fd5eda | 2021-05-04 18:33:49 -0700 | [diff] [blame] | 699 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
| 700 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); |
| 701 | return ret; |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 702 | } |
| 703 | |
Kirill A. Shutemov | 3122359 | 2013-09-12 15:14:01 -0700 | [diff] [blame] | 704 | entry = mk_huge_pmd(page, vma->vm_page_prot); |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 705 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 706 | folio_add_new_anon_rmap(folio, vma, haddr); |
| 707 | folio_add_lru_vma(folio, vma); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 708 | pgtable_trans_huge_deposit(vma->vm_mm, vmf->pmd, pgtable); |
| 709 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, entry); |
Bibo Mao | fca4057 | 2021-02-24 12:06:42 -0800 | [diff] [blame] | 710 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 711 | add_mm_counter(vma->vm_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
Kirill A. Shutemov | c481290 | 2017-11-15 17:35:37 -0800 | [diff] [blame] | 712 | mm_inc_nr_ptes(vma->vm_mm); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 713 | spin_unlock(vmf->ptl); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 714 | count_vm_event(THP_FAULT_ALLOC); |
Johannes Weiner | 9d82c69 | 2020-06-03 16:02:04 -0700 | [diff] [blame] | 715 | count_memcg_event_mm(vma->vm_mm, THP_FAULT_ALLOC); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 716 | } |
| 717 | |
David Rientjes | aa2e878 | 2012-05-29 15:06:17 -0700 | [diff] [blame] | 718 | return 0; |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 719 | unlock_release: |
| 720 | spin_unlock(vmf->ptl); |
| 721 | release: |
| 722 | if (pgtable) |
| 723 | pte_free(vma->vm_mm, pgtable); |
Kefeng Wang | cfe3236 | 2023-03-02 19:58:29 +0800 | [diff] [blame] | 724 | folio_put(folio); |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 725 | return ret; |
| 726 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 727 | } |
| 728 | |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 729 | /* |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 730 | * always: directly stall for all thp allocations |
| 731 | * defer: wake kswapd and fail if not immediately available |
| 732 | * defer+madvise: wake kswapd and directly stall for MADV_HUGEPAGE, otherwise |
| 733 | * fail if not immediately available |
| 734 | * madvise: directly stall for MADV_HUGEPAGE, otherwise fail if not immediately |
| 735 | * available |
| 736 | * never: never stall for any thp allocation |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 737 | */ |
Rik van Riel | 164cc4f | 2021-02-25 17:16:18 -0800 | [diff] [blame] | 738 | gfp_t vma_thp_gfp_mask(struct vm_area_struct *vma) |
Andrea Arcangeli | 0bbbc0b | 2011-01-13 15:47:05 -0800 | [diff] [blame] | 739 | { |
Rik van Riel | 164cc4f | 2021-02-25 17:16:18 -0800 | [diff] [blame] | 740 | const bool vma_madvised = vma && (vma->vm_flags & VM_HUGEPAGE); |
Michal Hocko | 89c83fb | 2018-11-02 15:48:31 -0700 | [diff] [blame] | 741 | |
David Rientjes | ac79f78 | 2019-09-04 12:54:18 -0700 | [diff] [blame] | 742 | /* Always do synchronous compaction */ |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 743 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags)) |
Andrea Arcangeli | a828260 | 2019-08-13 15:37:53 -0700 | [diff] [blame] | 744 | return GFP_TRANSHUGE | (vma_madvised ? 0 : __GFP_NORETRY); |
David Rientjes | ac79f78 | 2019-09-04 12:54:18 -0700 | [diff] [blame] | 745 | |
| 746 | /* Kick kcompactd and fail quickly */ |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 747 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags)) |
David Rientjes | 19deb76 | 2019-09-04 12:54:20 -0700 | [diff] [blame] | 748 | return GFP_TRANSHUGE_LIGHT | __GFP_KSWAPD_RECLAIM; |
David Rientjes | ac79f78 | 2019-09-04 12:54:18 -0700 | [diff] [blame] | 749 | |
| 750 | /* Synchronous compaction if madvised, otherwise kick kcompactd */ |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 751 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags)) |
David Rientjes | 19deb76 | 2019-09-04 12:54:20 -0700 | [diff] [blame] | 752 | return GFP_TRANSHUGE_LIGHT | |
| 753 | (vma_madvised ? __GFP_DIRECT_RECLAIM : |
| 754 | __GFP_KSWAPD_RECLAIM); |
David Rientjes | ac79f78 | 2019-09-04 12:54:18 -0700 | [diff] [blame] | 755 | |
| 756 | /* Only do synchronous compaction if madvised */ |
David Rientjes | 21440d7 | 2017-02-22 15:45:49 -0800 | [diff] [blame] | 757 | if (test_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags)) |
David Rientjes | 19deb76 | 2019-09-04 12:54:20 -0700 | [diff] [blame] | 758 | return GFP_TRANSHUGE_LIGHT | |
| 759 | (vma_madvised ? __GFP_DIRECT_RECLAIM : 0); |
David Rientjes | ac79f78 | 2019-09-04 12:54:18 -0700 | [diff] [blame] | 760 | |
David Rientjes | 19deb76 | 2019-09-04 12:54:20 -0700 | [diff] [blame] | 761 | return GFP_TRANSHUGE_LIGHT; |
Mel Gorman | 444eb2a4 | 2016-03-17 14:19:23 -0700 | [diff] [blame] | 762 | } |
| 763 | |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 764 | /* Caller must hold page table lock. */ |
Miaohe Lin | 2efeb8d | 2021-02-24 12:07:29 -0800 | [diff] [blame] | 765 | static void set_huge_zero_page(pgtable_t pgtable, struct mm_struct *mm, |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 766 | struct vm_area_struct *vma, unsigned long haddr, pmd_t *pmd, |
Kirill A. Shutemov | 5918d10 | 2013-04-29 15:08:44 -0700 | [diff] [blame] | 767 | struct page *zero_page) |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 768 | { |
| 769 | pmd_t entry; |
Andrew Morton | 7c41416 | 2015-09-08 14:58:43 -0700 | [diff] [blame] | 770 | if (!pmd_none(*pmd)) |
Miaohe Lin | 2efeb8d | 2021-02-24 12:07:29 -0800 | [diff] [blame] | 771 | return; |
Kirill A. Shutemov | 5918d10 | 2013-04-29 15:08:44 -0700 | [diff] [blame] | 772 | entry = mk_pmd(zero_page, vma->vm_page_prot); |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 773 | entry = pmd_mkhuge(entry); |
Qi Zheng | c8bb416 | 2022-08-18 16:27:48 +0800 | [diff] [blame] | 774 | pgtable_trans_huge_deposit(mm, pmd, pgtable); |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 775 | set_pmd_at(mm, haddr, pmd, entry); |
Kirill A. Shutemov | c481290 | 2017-11-15 17:35:37 -0800 | [diff] [blame] | 776 | mm_inc_nr_ptes(mm); |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 777 | } |
| 778 | |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 779 | vm_fault_t do_huge_pmd_anonymous_page(struct vm_fault *vmf) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 780 | { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 781 | struct vm_area_struct *vma = vmf->vma; |
Aneesh Kumar K.V | 077fcf1 | 2015-02-11 15:27:12 -0800 | [diff] [blame] | 782 | gfp_t gfp; |
Matthew Wilcox (Oracle) | cb196ee | 2022-05-12 20:23:01 -0700 | [diff] [blame] | 783 | struct folio *folio; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 784 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 785 | |
Yang Shi | 43675e6 | 2019-07-18 15:57:24 -0700 | [diff] [blame] | 786 | if (!transhuge_vma_suitable(vma, haddr)) |
Kirill A. Shutemov | c029255 | 2013-09-12 15:14:05 -0700 | [diff] [blame] | 787 | return VM_FAULT_FALLBACK; |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 788 | if (unlikely(anon_vma_prepare(vma))) |
| 789 | return VM_FAULT_OOM; |
Yang Shi | 4fa6893 | 2022-06-16 10:48:35 -0700 | [diff] [blame] | 790 | khugepaged_enter_vma(vma, vma->vm_flags); |
Yang Shi | d2081b2 | 2022-05-19 14:08:49 -0700 | [diff] [blame] | 791 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 792 | if (!(vmf->flags & FAULT_FLAG_WRITE) && |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 793 | !mm_forbids_zeropage(vma->vm_mm) && |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 794 | transparent_hugepage_use_zero_page()) { |
| 795 | pgtable_t pgtable; |
| 796 | struct page *zero_page; |
Souptick Joarder | 2b74030 | 2018-08-23 17:01:36 -0700 | [diff] [blame] | 797 | vm_fault_t ret; |
Joel Fernandes (Google) | 4cf5892 | 2019-01-03 15:28:34 -0800 | [diff] [blame] | 798 | pgtable = pte_alloc_one(vma->vm_mm); |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 799 | if (unlikely(!pgtable)) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 800 | return VM_FAULT_OOM; |
Aaron Lu | 6fcb52a | 2016-10-07 17:00:08 -0700 | [diff] [blame] | 801 | zero_page = mm_get_huge_zero_page(vma->vm_mm); |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 802 | if (unlikely(!zero_page)) { |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 803 | pte_free(vma->vm_mm, pgtable); |
Andi Kleen | 81ab420 | 2011-04-14 15:22:06 -0700 | [diff] [blame] | 804 | count_vm_event(THP_FAULT_FALLBACK); |
Kirill A. Shutemov | c029255 | 2013-09-12 15:14:05 -0700 | [diff] [blame] | 805 | return VM_FAULT_FALLBACK; |
Andi Kleen | 81ab420 | 2011-04-14 15:22:06 -0700 | [diff] [blame] | 806 | } |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 807 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 808 | ret = 0; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 809 | if (pmd_none(*vmf->pmd)) { |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 810 | ret = check_stable_address_space(vma->vm_mm); |
| 811 | if (ret) { |
| 812 | spin_unlock(vmf->ptl); |
Gerald Schaefer | bfe8cc1 | 2020-11-21 22:17:15 -0800 | [diff] [blame] | 813 | pte_free(vma->vm_mm, pgtable); |
Michal Hocko | 6b31d59 | 2017-08-18 15:16:15 -0700 | [diff] [blame] | 814 | } else if (userfaultfd_missing(vma)) { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 815 | spin_unlock(vmf->ptl); |
Gerald Schaefer | bfe8cc1 | 2020-11-21 22:17:15 -0800 | [diff] [blame] | 816 | pte_free(vma->vm_mm, pgtable); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 817 | ret = handle_userfault(vmf, VM_UFFD_MISSING); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 818 | VM_BUG_ON(ret & VM_FAULT_FALLBACK); |
| 819 | } else { |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 820 | set_huge_zero_page(pgtable, vma->vm_mm, vma, |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 821 | haddr, vmf->pmd, zero_page); |
Bibo Mao | fca4057 | 2021-02-24 12:06:42 -0800 | [diff] [blame] | 822 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 823 | spin_unlock(vmf->ptl); |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 824 | } |
Gerald Schaefer | bfe8cc1 | 2020-11-21 22:17:15 -0800 | [diff] [blame] | 825 | } else { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 826 | spin_unlock(vmf->ptl); |
Kirill A. Shutemov | bae473a | 2016-07-26 15:25:20 -0700 | [diff] [blame] | 827 | pte_free(vma->vm_mm, pgtable); |
Gerald Schaefer | bfe8cc1 | 2020-11-21 22:17:15 -0800 | [diff] [blame] | 828 | } |
Andrea Arcangeli | 6b251fc | 2015-09-04 15:46:20 -0700 | [diff] [blame] | 829 | return ret; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 830 | } |
Rik van Riel | 164cc4f | 2021-02-25 17:16:18 -0800 | [diff] [blame] | 831 | gfp = vma_thp_gfp_mask(vma); |
Matthew Wilcox (Oracle) | cb196ee | 2022-05-12 20:23:01 -0700 | [diff] [blame] | 832 | folio = vma_alloc_folio(gfp, HPAGE_PMD_ORDER, vma, haddr, true); |
| 833 | if (unlikely(!folio)) { |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 834 | count_vm_event(THP_FAULT_FALLBACK); |
Kirill A. Shutemov | c029255 | 2013-09-12 15:14:05 -0700 | [diff] [blame] | 835 | return VM_FAULT_FALLBACK; |
Kirill A. Shutemov | 128ec03 | 2013-09-12 15:14:03 -0700 | [diff] [blame] | 836 | } |
Matthew Wilcox (Oracle) | cb196ee | 2022-05-12 20:23:01 -0700 | [diff] [blame] | 837 | return __do_huge_pmd_anonymous_page(vmf, &folio->page, gfp); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 838 | } |
| 839 | |
Matthew Wilcox | ae18d6d | 2015-09-08 14:59:14 -0700 | [diff] [blame] | 840 | static void insert_pfn_pmd(struct vm_area_struct *vma, unsigned long addr, |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 841 | pmd_t *pmd, pfn_t pfn, pgprot_t prot, bool write, |
| 842 | pgtable_t pgtable) |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 843 | { |
| 844 | struct mm_struct *mm = vma->vm_mm; |
| 845 | pmd_t entry; |
| 846 | spinlock_t *ptl; |
| 847 | |
| 848 | ptl = pmd_lock(mm, pmd); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 849 | if (!pmd_none(*pmd)) { |
| 850 | if (write) { |
| 851 | if (pmd_pfn(*pmd) != pfn_t_to_pfn(pfn)) { |
| 852 | WARN_ON_ONCE(!is_huge_zero_pmd(*pmd)); |
| 853 | goto out_unlock; |
| 854 | } |
| 855 | entry = pmd_mkyoung(*pmd); |
| 856 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
| 857 | if (pmdp_set_access_flags(vma, addr, pmd, entry, 1)) |
| 858 | update_mmu_cache_pmd(vma, addr, pmd); |
| 859 | } |
| 860 | |
| 861 | goto out_unlock; |
| 862 | } |
| 863 | |
Dan Williams | f25748e3 | 2016-01-15 16:56:43 -0800 | [diff] [blame] | 864 | entry = pmd_mkhuge(pfn_t_pmd(pfn, prot)); |
| 865 | if (pfn_t_devmap(pfn)) |
| 866 | entry = pmd_mkdevmap(entry); |
Ross Zwisler | 01871e5 | 2016-01-15 16:56:02 -0800 | [diff] [blame] | 867 | if (write) { |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 868 | entry = pmd_mkyoung(pmd_mkdirty(entry)); |
| 869 | entry = maybe_pmd_mkwrite(entry, vma); |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 870 | } |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 871 | |
| 872 | if (pgtable) { |
| 873 | pgtable_trans_huge_deposit(mm, pmd, pgtable); |
Kirill A. Shutemov | c481290 | 2017-11-15 17:35:37 -0800 | [diff] [blame] | 874 | mm_inc_nr_ptes(mm); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 875 | pgtable = NULL; |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 876 | } |
| 877 | |
Ross Zwisler | 01871e5 | 2016-01-15 16:56:02 -0800 | [diff] [blame] | 878 | set_pmd_at(mm, addr, pmd, entry); |
| 879 | update_mmu_cache_pmd(vma, addr, pmd); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 880 | |
| 881 | out_unlock: |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 882 | spin_unlock(ptl); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 883 | if (pgtable) |
| 884 | pte_free(mm, pgtable); |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 885 | } |
| 886 | |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 887 | /** |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 888 | * vmf_insert_pfn_pmd - insert a pmd size pfn |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 889 | * @vmf: Structure describing the fault |
| 890 | * @pfn: pfn to insert |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 891 | * @write: whether it's a write fault |
| 892 | * |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 893 | * Insert a pmd size pfn. See vmf_insert_pfn() for additional info. |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 894 | * |
| 895 | * Return: vm_fault_t value. |
| 896 | */ |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 897 | vm_fault_t vmf_insert_pfn_pmd(struct vm_fault *vmf, pfn_t pfn, bool write) |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 898 | { |
Dan Williams | fce86ff | 2019-05-13 17:15:33 -0700 | [diff] [blame] | 899 | unsigned long addr = vmf->address & PMD_MASK; |
| 900 | struct vm_area_struct *vma = vmf->vma; |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 901 | pgprot_t pgprot = vma->vm_page_prot; |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 902 | pgtable_t pgtable = NULL; |
Dan Williams | fce86ff | 2019-05-13 17:15:33 -0700 | [diff] [blame] | 903 | |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 904 | /* |
| 905 | * If we had pmd_special, we could avoid all these restrictions, |
| 906 | * but we need to be consistent with PTEs and architectures that |
| 907 | * can't support a 'special' bit. |
| 908 | */ |
Dave Jiang | e1fb4a0 | 2018-08-17 15:43:40 -0700 | [diff] [blame] | 909 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
| 910 | !pfn_t_devmap(pfn)); |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 911 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
| 912 | (VM_PFNMAP|VM_MIXEDMAP)); |
| 913 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 914 | |
| 915 | if (addr < vma->vm_start || addr >= vma->vm_end) |
| 916 | return VM_FAULT_SIGBUS; |
Borislav Petkov | 308a047 | 2016-10-26 19:43:43 +0200 | [diff] [blame] | 917 | |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 918 | if (arch_needs_pgtable_deposit()) { |
Joel Fernandes (Google) | 4cf5892 | 2019-01-03 15:28:34 -0800 | [diff] [blame] | 919 | pgtable = pte_alloc_one(vma->vm_mm); |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 920 | if (!pgtable) |
| 921 | return VM_FAULT_OOM; |
| 922 | } |
| 923 | |
Borislav Petkov | 308a047 | 2016-10-26 19:43:43 +0200 | [diff] [blame] | 924 | track_pfn_insert(vma, &pgprot, pfn); |
| 925 | |
Dan Williams | fce86ff | 2019-05-13 17:15:33 -0700 | [diff] [blame] | 926 | insert_pfn_pmd(vma, addr, vmf->pmd, pfn, pgprot, write, pgtable); |
Matthew Wilcox | ae18d6d | 2015-09-08 14:59:14 -0700 | [diff] [blame] | 927 | return VM_FAULT_NOPAGE; |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 928 | } |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 929 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pmd); |
Matthew Wilcox | 5cad465 | 2015-09-08 14:58:54 -0700 | [diff] [blame] | 930 | |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 931 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 932 | static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 933 | { |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 934 | if (likely(vma->vm_flags & VM_WRITE)) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 935 | pud = pud_mkwrite(pud); |
| 936 | return pud; |
| 937 | } |
| 938 | |
| 939 | static void insert_pfn_pud(struct vm_area_struct *vma, unsigned long addr, |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 940 | pud_t *pud, pfn_t pfn, bool write) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 941 | { |
| 942 | struct mm_struct *mm = vma->vm_mm; |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 943 | pgprot_t prot = vma->vm_page_prot; |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 944 | pud_t entry; |
| 945 | spinlock_t *ptl; |
| 946 | |
| 947 | ptl = pud_lock(mm, pud); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 948 | if (!pud_none(*pud)) { |
| 949 | if (write) { |
| 950 | if (pud_pfn(*pud) != pfn_t_to_pfn(pfn)) { |
| 951 | WARN_ON_ONCE(!is_huge_zero_pud(*pud)); |
| 952 | goto out_unlock; |
| 953 | } |
| 954 | entry = pud_mkyoung(*pud); |
| 955 | entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma); |
| 956 | if (pudp_set_access_flags(vma, addr, pud, entry, 1)) |
| 957 | update_mmu_cache_pud(vma, addr, pud); |
| 958 | } |
| 959 | goto out_unlock; |
| 960 | } |
| 961 | |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 962 | entry = pud_mkhuge(pfn_t_pud(pfn, prot)); |
| 963 | if (pfn_t_devmap(pfn)) |
| 964 | entry = pud_mkdevmap(entry); |
| 965 | if (write) { |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 966 | entry = pud_mkyoung(pud_mkdirty(entry)); |
| 967 | entry = maybe_pud_mkwrite(entry, vma); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 968 | } |
| 969 | set_pud_at(mm, addr, pud, entry); |
| 970 | update_mmu_cache_pud(vma, addr, pud); |
Aneesh Kumar K.V | c6f3c5e | 2019-04-05 18:39:10 -0700 | [diff] [blame] | 971 | |
| 972 | out_unlock: |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 973 | spin_unlock(ptl); |
| 974 | } |
| 975 | |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 976 | /** |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 977 | * vmf_insert_pfn_pud - insert a pud size pfn |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 978 | * @vmf: Structure describing the fault |
| 979 | * @pfn: pfn to insert |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 980 | * @write: whether it's a write fault |
| 981 | * |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 982 | * Insert a pud size pfn. See vmf_insert_pfn() for additional info. |
Thomas Hellstrom (VMware) | 9a9731b | 2020-03-24 18:48:09 +0100 | [diff] [blame] | 983 | * |
| 984 | * Return: vm_fault_t value. |
| 985 | */ |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 986 | vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, pfn_t pfn, bool write) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 987 | { |
Dan Williams | fce86ff | 2019-05-13 17:15:33 -0700 | [diff] [blame] | 988 | unsigned long addr = vmf->address & PUD_MASK; |
| 989 | struct vm_area_struct *vma = vmf->vma; |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 990 | pgprot_t pgprot = vma->vm_page_prot; |
Dan Williams | fce86ff | 2019-05-13 17:15:33 -0700 | [diff] [blame] | 991 | |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 992 | /* |
| 993 | * If we had pud_special, we could avoid all these restrictions, |
| 994 | * but we need to be consistent with PTEs and architectures that |
| 995 | * can't support a 'special' bit. |
| 996 | */ |
Dave Jiang | 62ec0d8 | 2018-09-04 15:46:16 -0700 | [diff] [blame] | 997 | BUG_ON(!(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) && |
| 998 | !pfn_t_devmap(pfn)); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 999 | BUG_ON((vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP)) == |
| 1000 | (VM_PFNMAP|VM_MIXEDMAP)); |
| 1001 | BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags)); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1002 | |
| 1003 | if (addr < vma->vm_start || addr >= vma->vm_end) |
| 1004 | return VM_FAULT_SIGBUS; |
| 1005 | |
| 1006 | track_pfn_insert(vma, &pgprot, pfn); |
| 1007 | |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 1008 | insert_pfn_pud(vma, addr, vmf->pud, pfn, write); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1009 | return VM_FAULT_NOPAGE; |
| 1010 | } |
Lorenzo Stoakes | 7b806d2 | 2023-03-12 23:40:14 +0000 | [diff] [blame] | 1011 | EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1012 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
| 1013 | |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1014 | static void touch_pmd(struct vm_area_struct *vma, unsigned long addr, |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1015 | pmd_t *pmd, bool write) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1016 | { |
| 1017 | pmd_t _pmd; |
| 1018 | |
Kirill A. Shutemov | a8f9736 | 2017-11-27 06:21:25 +0300 | [diff] [blame] | 1019 | _pmd = pmd_mkyoung(*pmd); |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1020 | if (write) |
Kirill A. Shutemov | a8f9736 | 2017-11-27 06:21:25 +0300 | [diff] [blame] | 1021 | _pmd = pmd_mkdirty(_pmd); |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1022 | if (pmdp_set_access_flags(vma, addr & HPAGE_PMD_MASK, |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1023 | pmd, _pmd, write)) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1024 | update_mmu_cache_pmd(vma, addr, pmd); |
| 1025 | } |
| 1026 | |
| 1027 | struct page *follow_devmap_pmd(struct vm_area_struct *vma, unsigned long addr, |
Keith Busch | df06b37 | 2018-10-26 15:10:28 -0700 | [diff] [blame] | 1028 | pmd_t *pmd, int flags, struct dev_pagemap **pgmap) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1029 | { |
| 1030 | unsigned long pfn = pmd_pfn(*pmd); |
| 1031 | struct mm_struct *mm = vma->vm_mm; |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1032 | struct page *page; |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1033 | int ret; |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1034 | |
| 1035 | assert_spin_locked(pmd_lockptr(mm, pmd)); |
| 1036 | |
Linus Torvalds | f6f3732 | 2017-12-15 18:53:22 -0800 | [diff] [blame] | 1037 | if (flags & FOLL_WRITE && !pmd_write(*pmd)) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1038 | return NULL; |
| 1039 | |
| 1040 | if (pmd_present(*pmd) && pmd_devmap(*pmd)) |
| 1041 | /* pass */; |
| 1042 | else |
| 1043 | return NULL; |
| 1044 | |
| 1045 | if (flags & FOLL_TOUCH) |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1046 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1047 | |
| 1048 | /* |
| 1049 | * device mapped pages can only be returned if the |
| 1050 | * caller will manage the page reference count. |
| 1051 | */ |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1052 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1053 | return ERR_PTR(-EEXIST); |
| 1054 | |
| 1055 | pfn += (addr & ~PMD_MASK) >> PAGE_SHIFT; |
Keith Busch | df06b37 | 2018-10-26 15:10:28 -0700 | [diff] [blame] | 1056 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
| 1057 | if (!*pgmap) |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1058 | return ERR_PTR(-EFAULT); |
| 1059 | page = pfn_to_page(pfn); |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1060 | ret = try_grab_page(page, flags); |
| 1061 | if (ret) |
| 1062 | page = ERR_PTR(ret); |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1063 | |
| 1064 | return page; |
| 1065 | } |
| 1066 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1067 | int copy_huge_pmd(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
| 1068 | pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long addr, |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1069 | struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1070 | { |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 1071 | spinlock_t *dst_ptl, *src_ptl; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1072 | struct page *src_page; |
| 1073 | pmd_t pmd; |
Matthew Wilcox | 12c9d70 | 2016-02-02 16:57:57 -0800 | [diff] [blame] | 1074 | pgtable_t pgtable = NULL; |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1075 | int ret = -ENOMEM; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1076 | |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1077 | /* Skip if can be re-fill on fault */ |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1078 | if (!vma_is_anonymous(dst_vma)) |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1079 | return 0; |
| 1080 | |
Joel Fernandes (Google) | 4cf5892 | 2019-01-03 15:28:34 -0800 | [diff] [blame] | 1081 | pgtable = pte_alloc_one(dst_mm); |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1082 | if (unlikely(!pgtable)) |
| 1083 | goto out; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1084 | |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 1085 | dst_ptl = pmd_lock(dst_mm, dst_pmd); |
| 1086 | src_ptl = pmd_lockptr(src_mm, src_pmd); |
| 1087 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1088 | |
| 1089 | ret = -EAGAIN; |
| 1090 | pmd = *src_pmd; |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1091 | |
| 1092 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION |
| 1093 | if (unlikely(is_swap_pmd(pmd))) { |
| 1094 | swp_entry_t entry = pmd_to_swp_entry(pmd); |
| 1095 | |
| 1096 | VM_BUG_ON(!is_pmd_migration_entry(pmd)); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1097 | if (!is_readable_migration_entry(entry)) { |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 1098 | entry = make_readable_migration_entry( |
| 1099 | swp_offset(entry)); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1100 | pmd = swp_entry_to_pmd(entry); |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 1101 | if (pmd_swp_soft_dirty(*src_pmd)) |
| 1102 | pmd = pmd_swp_mksoft_dirty(pmd); |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1103 | if (pmd_swp_uffd_wp(*src_pmd)) |
| 1104 | pmd = pmd_swp_mkuffd_wp(pmd); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1105 | set_pmd_at(src_mm, addr, src_pmd, pmd); |
| 1106 | } |
Zi Yan | dd8a67f | 2017-11-02 15:59:47 -0700 | [diff] [blame] | 1107 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
Kirill A. Shutemov | af5b0f6 | 2017-11-15 17:35:40 -0800 | [diff] [blame] | 1108 | mm_inc_nr_ptes(dst_mm); |
Zi Yan | dd8a67f | 2017-11-02 15:59:47 -0700 | [diff] [blame] | 1109 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1110 | if (!userfaultfd_wp(dst_vma)) |
| 1111 | pmd = pmd_swp_clear_uffd_wp(pmd); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1112 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); |
| 1113 | ret = 0; |
| 1114 | goto out_unlock; |
| 1115 | } |
| 1116 | #endif |
| 1117 | |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1118 | if (unlikely(!pmd_trans_huge(pmd))) { |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1119 | pte_free(dst_mm, pgtable); |
| 1120 | goto out_unlock; |
| 1121 | } |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 1122 | /* |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 1123 | * When page table lock is held, the huge zero pmd should not be |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 1124 | * under splitting since we don't split the page itself, only pmd to |
| 1125 | * a page table. |
| 1126 | */ |
| 1127 | if (is_huge_zero_pmd(pmd)) { |
Kirill A. Shutemov | 97ae174 | 2012-12-12 13:51:06 -0800 | [diff] [blame] | 1128 | /* |
| 1129 | * get_huge_zero_page() will never allocate a new page here, |
| 1130 | * since we already have a zero page to copy. It just takes a |
| 1131 | * reference. |
| 1132 | */ |
Peter Xu | 5fc7a5f | 2021-06-30 18:48:59 -0700 | [diff] [blame] | 1133 | mm_get_huge_zero_page(dst_mm); |
| 1134 | goto out_zero_page; |
Kirill A. Shutemov | fc9fe82 | 2012-12-12 13:50:51 -0800 | [diff] [blame] | 1135 | } |
Mel Gorman | de466bd | 2013-12-18 17:08:42 -0800 | [diff] [blame] | 1136 | |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1137 | src_page = pmd_page(pmd); |
| 1138 | VM_BUG_ON_PAGE(!PageHead(src_page), src_page); |
Peter Xu | d042035 | 2020-09-25 18:26:00 -0400 | [diff] [blame] | 1139 | |
David Hildenbrand | fb3d824 | 2022-05-09 18:20:43 -0700 | [diff] [blame] | 1140 | get_page(src_page); |
| 1141 | if (unlikely(page_try_dup_anon_rmap(src_page, true, src_vma))) { |
| 1142 | /* Page maybe pinned: split and retry the fault on PTEs. */ |
| 1143 | put_page(src_page); |
Peter Xu | d042035 | 2020-09-25 18:26:00 -0400 | [diff] [blame] | 1144 | pte_free(dst_mm, pgtable); |
| 1145 | spin_unlock(src_ptl); |
| 1146 | spin_unlock(dst_ptl); |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1147 | __split_huge_pmd(src_vma, src_pmd, addr, false, NULL); |
Peter Xu | d042035 | 2020-09-25 18:26:00 -0400 | [diff] [blame] | 1148 | return -EAGAIN; |
| 1149 | } |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1150 | add_mm_counter(dst_mm, MM_ANONPAGES, HPAGE_PMD_NR); |
Peter Xu | 5fc7a5f | 2021-06-30 18:48:59 -0700 | [diff] [blame] | 1151 | out_zero_page: |
Kirill A. Shutemov | c481290 | 2017-11-15 17:35:37 -0800 | [diff] [blame] | 1152 | mm_inc_nr_ptes(dst_mm); |
Kirill A. Shutemov | 628d47c | 2016-07-26 15:25:42 -0700 | [diff] [blame] | 1153 | pgtable_trans_huge_deposit(dst_mm, dst_pmd, pgtable); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1154 | pmdp_set_wrprotect(src_mm, addr, src_pmd); |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 1155 | if (!userfaultfd_wp(dst_vma)) |
| 1156 | pmd = pmd_clear_uffd_wp(pmd); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1157 | pmd = pmd_mkold(pmd_wrprotect(pmd)); |
| 1158 | set_pmd_at(dst_mm, addr, dst_pmd, pmd); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1159 | |
| 1160 | ret = 0; |
| 1161 | out_unlock: |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 1162 | spin_unlock(src_ptl); |
| 1163 | spin_unlock(dst_ptl); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1164 | out: |
| 1165 | return ret; |
| 1166 | } |
| 1167 | |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1168 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
| 1169 | static void touch_pud(struct vm_area_struct *vma, unsigned long addr, |
Miaohe Lin | 5fe653e | 2022-07-04 21:21:49 +0800 | [diff] [blame] | 1170 | pud_t *pud, bool write) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1171 | { |
| 1172 | pud_t _pud; |
| 1173 | |
Kirill A. Shutemov | a8f9736 | 2017-11-27 06:21:25 +0300 | [diff] [blame] | 1174 | _pud = pud_mkyoung(*pud); |
Miaohe Lin | 5fe653e | 2022-07-04 21:21:49 +0800 | [diff] [blame] | 1175 | if (write) |
Kirill A. Shutemov | a8f9736 | 2017-11-27 06:21:25 +0300 | [diff] [blame] | 1176 | _pud = pud_mkdirty(_pud); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1177 | if (pudp_set_access_flags(vma, addr & HPAGE_PUD_MASK, |
Miaohe Lin | 5fe653e | 2022-07-04 21:21:49 +0800 | [diff] [blame] | 1178 | pud, _pud, write)) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1179 | update_mmu_cache_pud(vma, addr, pud); |
| 1180 | } |
| 1181 | |
| 1182 | struct page *follow_devmap_pud(struct vm_area_struct *vma, unsigned long addr, |
Keith Busch | df06b37 | 2018-10-26 15:10:28 -0700 | [diff] [blame] | 1183 | pud_t *pud, int flags, struct dev_pagemap **pgmap) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1184 | { |
| 1185 | unsigned long pfn = pud_pfn(*pud); |
| 1186 | struct mm_struct *mm = vma->vm_mm; |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1187 | struct page *page; |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1188 | int ret; |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1189 | |
| 1190 | assert_spin_locked(pud_lockptr(mm, pud)); |
| 1191 | |
Linus Torvalds | f6f3732 | 2017-12-15 18:53:22 -0800 | [diff] [blame] | 1192 | if (flags & FOLL_WRITE && !pud_write(*pud)) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1193 | return NULL; |
| 1194 | |
| 1195 | if (pud_present(*pud) && pud_devmap(*pud)) |
| 1196 | /* pass */; |
| 1197 | else |
| 1198 | return NULL; |
| 1199 | |
| 1200 | if (flags & FOLL_TOUCH) |
Miaohe Lin | 5fe653e | 2022-07-04 21:21:49 +0800 | [diff] [blame] | 1201 | touch_pud(vma, addr, pud, flags & FOLL_WRITE); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1202 | |
| 1203 | /* |
| 1204 | * device mapped pages can only be returned if the |
| 1205 | * caller will manage the page reference count. |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1206 | * |
| 1207 | * At least one of FOLL_GET | FOLL_PIN must be set, so assert that here: |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1208 | */ |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1209 | if (!(flags & (FOLL_GET | FOLL_PIN))) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1210 | return ERR_PTR(-EEXIST); |
| 1211 | |
| 1212 | pfn += (addr & ~PUD_MASK) >> PAGE_SHIFT; |
Keith Busch | df06b37 | 2018-10-26 15:10:28 -0700 | [diff] [blame] | 1213 | *pgmap = get_dev_pagemap(pfn, *pgmap); |
| 1214 | if (!*pgmap) |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1215 | return ERR_PTR(-EFAULT); |
| 1216 | page = pfn_to_page(pfn); |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1217 | |
| 1218 | ret = try_grab_page(page, flags); |
| 1219 | if (ret) |
| 1220 | page = ERR_PTR(ret); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1221 | |
| 1222 | return page; |
| 1223 | } |
| 1224 | |
| 1225 | int copy_huge_pud(struct mm_struct *dst_mm, struct mm_struct *src_mm, |
| 1226 | pud_t *dst_pud, pud_t *src_pud, unsigned long addr, |
| 1227 | struct vm_area_struct *vma) |
| 1228 | { |
| 1229 | spinlock_t *dst_ptl, *src_ptl; |
| 1230 | pud_t pud; |
| 1231 | int ret; |
| 1232 | |
| 1233 | dst_ptl = pud_lock(dst_mm, dst_pud); |
| 1234 | src_ptl = pud_lockptr(src_mm, src_pud); |
| 1235 | spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING); |
| 1236 | |
| 1237 | ret = -EAGAIN; |
| 1238 | pud = *src_pud; |
| 1239 | if (unlikely(!pud_trans_huge(pud) && !pud_devmap(pud))) |
| 1240 | goto out_unlock; |
| 1241 | |
| 1242 | /* |
| 1243 | * When page table lock is held, the huge zero pud should not be |
| 1244 | * under splitting since we don't split the page itself, only pud to |
| 1245 | * a page table. |
| 1246 | */ |
| 1247 | if (is_huge_zero_pud(pud)) { |
| 1248 | /* No huge zero pud yet */ |
| 1249 | } |
| 1250 | |
David Hildenbrand | fb3d824 | 2022-05-09 18:20:43 -0700 | [diff] [blame] | 1251 | /* |
| 1252 | * TODO: once we support anonymous pages, use page_try_dup_anon_rmap() |
| 1253 | * and split if duplicating fails. |
| 1254 | */ |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1255 | pudp_set_wrprotect(src_mm, addr, src_pud); |
| 1256 | pud = pud_mkold(pud_wrprotect(pud)); |
| 1257 | set_pud_at(dst_mm, addr, dst_pud, pud); |
| 1258 | |
| 1259 | ret = 0; |
| 1260 | out_unlock: |
| 1261 | spin_unlock(src_ptl); |
| 1262 | spin_unlock(dst_ptl); |
| 1263 | return ret; |
| 1264 | } |
| 1265 | |
| 1266 | void huge_pud_set_accessed(struct vm_fault *vmf, pud_t orig_pud) |
| 1267 | { |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1268 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
| 1269 | |
| 1270 | vmf->ptl = pud_lock(vmf->vma->vm_mm, vmf->pud); |
| 1271 | if (unlikely(!pud_same(*vmf->pud, orig_pud))) |
| 1272 | goto unlock; |
| 1273 | |
Miaohe Lin | 5fe653e | 2022-07-04 21:21:49 +0800 | [diff] [blame] | 1274 | touch_pud(vmf->vma, vmf->address, vmf->pud, write); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1275 | unlock: |
| 1276 | spin_unlock(vmf->ptl); |
| 1277 | } |
| 1278 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
| 1279 | |
Yang Shi | 5db4f15 | 2021-06-30 18:51:35 -0700 | [diff] [blame] | 1280 | void huge_pmd_set_accessed(struct vm_fault *vmf) |
Will Deacon | a1dd450 | 2012-12-11 16:01:27 -0800 | [diff] [blame] | 1281 | { |
Minchan Kim | 20f664a | 2017-01-10 16:57:51 -0800 | [diff] [blame] | 1282 | bool write = vmf->flags & FAULT_FLAG_WRITE; |
Will Deacon | a1dd450 | 2012-12-11 16:01:27 -0800 | [diff] [blame] | 1283 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1284 | vmf->ptl = pmd_lock(vmf->vma->vm_mm, vmf->pmd); |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1285 | if (unlikely(!pmd_same(*vmf->pmd, vmf->orig_pmd))) |
Will Deacon | a1dd450 | 2012-12-11 16:01:27 -0800 | [diff] [blame] | 1286 | goto unlock; |
| 1287 | |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1288 | touch_pmd(vmf->vma, vmf->address, vmf->pmd, write); |
Will Deacon | a1dd450 | 2012-12-11 16:01:27 -0800 | [diff] [blame] | 1289 | |
| 1290 | unlock: |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1291 | spin_unlock(vmf->ptl); |
Will Deacon | a1dd450 | 2012-12-11 16:01:27 -0800 | [diff] [blame] | 1292 | } |
| 1293 | |
Yang Shi | 5db4f15 | 2021-06-30 18:51:35 -0700 | [diff] [blame] | 1294 | vm_fault_t do_huge_pmd_wp_page(struct vm_fault *vmf) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1295 | { |
David Hildenbrand | c89357e | 2022-05-09 18:20:45 -0700 | [diff] [blame] | 1296 | const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1297 | struct vm_area_struct *vma = vmf->vma; |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1298 | struct folio *folio; |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1299 | struct page *page; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1300 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
Yang Shi | 5db4f15 | 2021-06-30 18:51:35 -0700 | [diff] [blame] | 1301 | pmd_t orig_pmd = vmf->orig_pmd; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1302 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1303 | vmf->ptl = pmd_lockptr(vma->vm_mm, vmf->pmd); |
Sasha Levin | 81d1b09 | 2014-10-09 15:28:10 -0700 | [diff] [blame] | 1304 | VM_BUG_ON_VMA(!vma->anon_vma, vma); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1305 | |
Kirill A. Shutemov | 93b4796 | 2012-12-12 13:50:54 -0800 | [diff] [blame] | 1306 | if (is_huge_zero_pmd(orig_pmd)) |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1307 | goto fallback; |
| 1308 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1309 | spin_lock(vmf->ptl); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1310 | |
| 1311 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { |
| 1312 | spin_unlock(vmf->ptl); |
| 1313 | return 0; |
| 1314 | } |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1315 | |
| 1316 | page = pmd_page(orig_pmd); |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1317 | folio = page_folio(page); |
Miaohe Lin | f6004e7 | 2021-05-04 18:34:02 -0700 | [diff] [blame] | 1318 | VM_BUG_ON_PAGE(!PageHead(page), page); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1319 | |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1320 | /* Early check when only holding the PT lock. */ |
| 1321 | if (PageAnonExclusive(page)) |
| 1322 | goto reuse; |
| 1323 | |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1324 | if (!folio_trylock(folio)) { |
| 1325 | folio_get(folio); |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1326 | spin_unlock(vmf->ptl); |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1327 | folio_lock(folio); |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1328 | spin_lock(vmf->ptl); |
| 1329 | if (unlikely(!pmd_same(*vmf->pmd, orig_pmd))) { |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1330 | spin_unlock(vmf->ptl); |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1331 | folio_unlock(folio); |
| 1332 | folio_put(folio); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1333 | return 0; |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1334 | } |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1335 | folio_put(folio); |
Huang Ying | ba3c4ce | 2017-09-06 16:22:19 -0700 | [diff] [blame] | 1336 | } |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1337 | |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1338 | /* Recheck after temporarily dropping the PT lock. */ |
| 1339 | if (PageAnonExclusive(page)) { |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1340 | folio_unlock(folio); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1341 | goto reuse; |
| 1342 | } |
| 1343 | |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1344 | /* |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1345 | * See do_wp_page(): we can only reuse the folio exclusively if |
| 1346 | * there are no additional references. Note that we always drain |
| 1347 | * the LRU pagevecs immediately after adding a THP. |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1348 | */ |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1349 | if (folio_ref_count(folio) > |
| 1350 | 1 + folio_test_swapcache(folio) * folio_nr_pages(folio)) |
David Hildenbrand | 3bff7e3 | 2022-03-24 18:13:43 -0700 | [diff] [blame] | 1351 | goto unlock_fallback; |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1352 | if (folio_test_swapcache(folio)) |
| 1353 | folio_free_swap(folio); |
| 1354 | if (folio_ref_count(folio) == 1) { |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1355 | pmd_t entry; |
David Hildenbrand | 6c54dc6 | 2022-05-09 18:20:43 -0700 | [diff] [blame] | 1356 | |
| 1357 | page_move_anon_rmap(page, vma); |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1358 | folio_unlock(folio); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1359 | reuse: |
David Hildenbrand | c89357e | 2022-05-09 18:20:45 -0700 | [diff] [blame] | 1360 | if (unlikely(unshare)) { |
| 1361 | spin_unlock(vmf->ptl); |
| 1362 | return 0; |
| 1363 | } |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1364 | entry = pmd_mkyoung(orig_pmd); |
Linus Torvalds | f55e101 | 2017-11-29 09:01:01 -0800 | [diff] [blame] | 1365 | entry = maybe_pmd_mkwrite(pmd_mkdirty(entry), vma); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1366 | if (pmdp_set_access_flags(vma, haddr, vmf->pmd, entry, 1)) |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1367 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1368 | spin_unlock(vmf->ptl); |
David Hildenbrand | cb8d863 | 2022-10-21 12:11:35 +0200 | [diff] [blame] | 1369 | return 0; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1370 | } |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1371 | |
David Hildenbrand | 3bff7e3 | 2022-03-24 18:13:43 -0700 | [diff] [blame] | 1372 | unlock_fallback: |
Matthew Wilcox (Oracle) | 2fad3d1 | 2022-09-02 20:46:38 +0100 | [diff] [blame] | 1373 | folio_unlock(folio); |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1374 | spin_unlock(vmf->ptl); |
Kirill A. Shutemov | 3917c80 | 2020-06-03 16:00:27 -0700 | [diff] [blame] | 1375 | fallback: |
| 1376 | __split_huge_pmd(vma, vmf->pmd, vmf->address, false, NULL); |
| 1377 | return VM_FAULT_FALLBACK; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1378 | } |
| 1379 | |
David Hildenbrand | c27f479 | 2022-11-08 18:46:48 +0100 | [diff] [blame] | 1380 | static inline bool can_change_pmd_writable(struct vm_area_struct *vma, |
| 1381 | unsigned long addr, pmd_t pmd) |
| 1382 | { |
| 1383 | struct page *page; |
| 1384 | |
| 1385 | if (WARN_ON_ONCE(!(vma->vm_flags & VM_WRITE))) |
| 1386 | return false; |
| 1387 | |
| 1388 | /* Don't touch entries that are not even readable (NUMA hinting). */ |
| 1389 | if (pmd_protnone(pmd)) |
| 1390 | return false; |
| 1391 | |
| 1392 | /* Do we need write faults for softdirty tracking? */ |
| 1393 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) |
| 1394 | return false; |
| 1395 | |
| 1396 | /* Do we need write faults for uffd-wp tracking? */ |
| 1397 | if (userfaultfd_huge_pmd_wp(vma, pmd)) |
| 1398 | return false; |
| 1399 | |
| 1400 | if (!(vma->vm_flags & VM_SHARED)) { |
| 1401 | /* See can_change_pte_writable(). */ |
| 1402 | page = vm_normal_page_pmd(vma, addr, pmd); |
| 1403 | return page && PageAnon(page) && PageAnonExclusive(page); |
| 1404 | } |
| 1405 | |
| 1406 | /* See can_change_pte_writable(). */ |
| 1407 | return pmd_dirty(pmd); |
| 1408 | } |
| 1409 | |
David Hildenbrand | 5535be3 | 2022-08-09 22:56:40 +0200 | [diff] [blame] | 1410 | /* FOLL_FORCE can write to even unwritable PMDs in COW mappings. */ |
| 1411 | static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, |
| 1412 | struct vm_area_struct *vma, |
| 1413 | unsigned int flags) |
Keno Fischer | 8310d48 | 2017-01-24 15:17:48 -0800 | [diff] [blame] | 1414 | { |
David Hildenbrand | 5535be3 | 2022-08-09 22:56:40 +0200 | [diff] [blame] | 1415 | /* If the pmd is writable, we can write to the page. */ |
| 1416 | if (pmd_write(pmd)) |
| 1417 | return true; |
| 1418 | |
| 1419 | /* Maybe FOLL_FORCE is set to override it? */ |
| 1420 | if (!(flags & FOLL_FORCE)) |
| 1421 | return false; |
| 1422 | |
| 1423 | /* But FOLL_FORCE has no effect on shared mappings */ |
| 1424 | if (vma->vm_flags & (VM_MAYSHARE | VM_SHARED)) |
| 1425 | return false; |
| 1426 | |
| 1427 | /* ... or read-only private ones */ |
| 1428 | if (!(vma->vm_flags & VM_MAYWRITE)) |
| 1429 | return false; |
| 1430 | |
| 1431 | /* ... or already writable ones that just need to take a write fault */ |
| 1432 | if (vma->vm_flags & VM_WRITE) |
| 1433 | return false; |
| 1434 | |
| 1435 | /* |
| 1436 | * See can_change_pte_writable(): we broke COW and could map the page |
| 1437 | * writable if we have an exclusive anonymous page ... |
| 1438 | */ |
| 1439 | if (!page || !PageAnon(page) || !PageAnonExclusive(page)) |
| 1440 | return false; |
| 1441 | |
| 1442 | /* ... and a write-fault isn't required for other reasons. */ |
| 1443 | if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) |
| 1444 | return false; |
| 1445 | return !userfaultfd_huge_pmd_wp(vma, pmd); |
Keno Fischer | 8310d48 | 2017-01-24 15:17:48 -0800 | [diff] [blame] | 1446 | } |
| 1447 | |
David Rientjes | b676b29 | 2012-10-08 16:34:03 -0700 | [diff] [blame] | 1448 | struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1449 | unsigned long addr, |
| 1450 | pmd_t *pmd, |
| 1451 | unsigned int flags) |
| 1452 | { |
David Rientjes | b676b29 | 2012-10-08 16:34:03 -0700 | [diff] [blame] | 1453 | struct mm_struct *mm = vma->vm_mm; |
David Hildenbrand | 5535be3 | 2022-08-09 22:56:40 +0200 | [diff] [blame] | 1454 | struct page *page; |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1455 | int ret; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1456 | |
Kirill A. Shutemov | c4088eb | 2013-11-14 14:31:04 -0800 | [diff] [blame] | 1457 | assert_spin_locked(pmd_lockptr(mm, pmd)); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1458 | |
David Hildenbrand | 5535be3 | 2022-08-09 22:56:40 +0200 | [diff] [blame] | 1459 | page = pmd_page(*pmd); |
| 1460 | VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); |
| 1461 | |
| 1462 | if ((flags & FOLL_WRITE) && |
| 1463 | !can_follow_write_pmd(*pmd, page, vma, flags)) |
| 1464 | return NULL; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1465 | |
Kirill A. Shutemov | 85facf2 | 2013-02-04 14:28:42 -0800 | [diff] [blame] | 1466 | /* Avoid dumping huge zero page */ |
| 1467 | if ((flags & FOLL_DUMP) && is_huge_zero_pmd(*pmd)) |
| 1468 | return ERR_PTR(-EFAULT); |
| 1469 | |
Mel Gorman | 2b4847e | 2013-12-18 17:08:32 -0800 | [diff] [blame] | 1470 | /* Full NUMA hinting faults to serialise migration in fault paths */ |
David Hildenbrand | 474098e | 2022-08-25 18:46:57 +0200 | [diff] [blame] | 1471 | if (pmd_protnone(*pmd) && !gup_can_follow_protnone(flags)) |
David Hildenbrand | 5535be3 | 2022-08-09 22:56:40 +0200 | [diff] [blame] | 1472 | return NULL; |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1473 | |
David Hildenbrand | 84209e8 | 2022-11-16 11:26:48 +0100 | [diff] [blame] | 1474 | if (!pmd_write(*pmd) && gup_must_unshare(vma, flags, page)) |
David Hildenbrand | a7f2266 | 2022-05-09 18:20:45 -0700 | [diff] [blame] | 1475 | return ERR_PTR(-EMLINK); |
| 1476 | |
David Hildenbrand | b6a2619 | 2022-05-09 18:20:45 -0700 | [diff] [blame] | 1477 | VM_BUG_ON_PAGE((flags & FOLL_PIN) && PageAnon(page) && |
| 1478 | !PageAnonExclusive(page), page); |
| 1479 | |
Logan Gunthorpe | 0f08923 | 2022-10-21 11:41:08 -0600 | [diff] [blame] | 1480 | ret = try_grab_page(page, flags); |
| 1481 | if (ret) |
| 1482 | return ERR_PTR(ret); |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1483 | |
Dan Williams | 3565fce | 2016-01-15 16:56:55 -0800 | [diff] [blame] | 1484 | if (flags & FOLL_TOUCH) |
Miaohe Lin | a69e471 | 2022-07-04 21:21:50 +0800 | [diff] [blame] | 1485 | touch_pmd(vma, addr, pmd, flags & FOLL_WRITE); |
John Hubbard | 3faa52c | 2020-04-01 21:05:29 -0700 | [diff] [blame] | 1486 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1487 | page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; |
Dan Williams | ca120cf | 2016-09-03 10:38:03 -0700 | [diff] [blame] | 1488 | VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1489 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1490 | return page; |
| 1491 | } |
| 1492 | |
Mel Gorman | d10e63f | 2012-10-25 14:16:31 +0200 | [diff] [blame] | 1493 | /* NUMA hinting page fault entry point for trans huge pmds */ |
Yang Shi | 5db4f15 | 2021-06-30 18:51:35 -0700 | [diff] [blame] | 1494 | vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf) |
Mel Gorman | d10e63f | 2012-10-25 14:16:31 +0200 | [diff] [blame] | 1495 | { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1496 | struct vm_area_struct *vma = vmf->vma; |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1497 | pmd_t oldpmd = vmf->orig_pmd; |
| 1498 | pmd_t pmd; |
Mel Gorman | b32967f | 2012-11-19 12:35:47 +0000 | [diff] [blame] | 1499 | struct page *page; |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1500 | unsigned long haddr = vmf->address & HPAGE_PMD_MASK; |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1501 | int page_nid = NUMA_NO_NODE; |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1502 | int target_nid, last_cpupid = (-1 & LAST_CPUPID_MASK); |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1503 | bool migrated = false, writable = false; |
Peter Zijlstra | 6688cc0 | 2013-10-07 11:29:24 +0100 | [diff] [blame] | 1504 | int flags = 0; |
Mel Gorman | d10e63f | 2012-10-25 14:16:31 +0200 | [diff] [blame] | 1505 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1506 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1507 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1508 | spin_unlock(vmf->ptl); |
Mel Gorman | de466bd | 2013-12-18 17:08:42 -0800 | [diff] [blame] | 1509 | goto out; |
| 1510 | } |
| 1511 | |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1512 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1513 | |
| 1514 | /* |
| 1515 | * Detect now whether the PMD could be writable; this information |
| 1516 | * is only valid while holding the PT lock. |
| 1517 | */ |
| 1518 | writable = pmd_write(pmd); |
| 1519 | if (!writable && vma_wants_manual_pte_write_upgrade(vma) && |
| 1520 | can_change_pmd_writable(vma, vmf->address, pmd)) |
| 1521 | writable = true; |
| 1522 | |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1523 | page = vm_normal_page_pmd(vma, haddr, pmd); |
| 1524 | if (!page) |
| 1525 | goto out_map; |
| 1526 | |
| 1527 | /* See similar comment in do_numa_page for explanation */ |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1528 | if (!writable) |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1529 | flags |= TNF_NO_GROUP; |
| 1530 | |
| 1531 | page_nid = page_to_nid(page); |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1532 | /* |
| 1533 | * For memory tiering mode, cpupid of slow memory page is used |
| 1534 | * to record page access time. So use default value. |
| 1535 | */ |
| 1536 | if (node_is_toptier(page_nid)) |
| 1537 | last_cpupid = page_cpupid_last(page); |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1538 | target_nid = numa_migrate_prep(page, vma, haddr, page_nid, |
| 1539 | &flags); |
| 1540 | |
| 1541 | if (target_nid == NUMA_NO_NODE) { |
| 1542 | put_page(page); |
| 1543 | goto out_map; |
| 1544 | } |
| 1545 | |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1546 | spin_unlock(vmf->ptl); |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1547 | writable = false; |
Peter Zijlstra | 8b1b436 | 2017-06-07 18:05:07 +0200 | [diff] [blame] | 1548 | |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1549 | migrated = migrate_misplaced_page(page, vma, target_nid); |
Peter Zijlstra | 6688cc0 | 2013-10-07 11:29:24 +0100 | [diff] [blame] | 1550 | if (migrated) { |
| 1551 | flags |= TNF_MIGRATED; |
Mel Gorman | 8191acb | 2013-10-07 11:28:45 +0100 | [diff] [blame] | 1552 | page_nid = target_nid; |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1553 | } else { |
Mel Gorman | 074c238 | 2015-03-25 15:55:42 -0700 | [diff] [blame] | 1554 | flags |= TNF_MIGRATE_FAIL; |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1555 | vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); |
| 1556 | if (unlikely(!pmd_same(oldpmd, *vmf->pmd))) { |
| 1557 | spin_unlock(vmf->ptl); |
| 1558 | goto out; |
| 1559 | } |
| 1560 | goto out_map; |
| 1561 | } |
Mel Gorman | b891663 | 2013-10-07 11:28:44 +0100 | [diff] [blame] | 1562 | |
| 1563 | out: |
Anshuman Khandual | 98fa15f | 2019-03-05 15:42:58 -0800 | [diff] [blame] | 1564 | if (page_nid != NUMA_NO_NODE) |
Jan Kara | 82b0f8c | 2016-12-14 15:06:58 -0800 | [diff] [blame] | 1565 | task_numa_fault(last_cpupid, page_nid, HPAGE_PMD_NR, |
Aneesh Kumar K.V | 9a8b300 | 2017-02-24 14:59:56 -0800 | [diff] [blame] | 1566 | flags); |
Mel Gorman | 8191acb | 2013-10-07 11:28:45 +0100 | [diff] [blame] | 1567 | |
Mel Gorman | d10e63f | 2012-10-25 14:16:31 +0200 | [diff] [blame] | 1568 | return 0; |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1569 | |
| 1570 | out_map: |
| 1571 | /* Restore the PMD */ |
| 1572 | pmd = pmd_modify(oldpmd, vma->vm_page_prot); |
| 1573 | pmd = pmd_mkyoung(pmd); |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1574 | if (writable) |
Yang Shi | c5b5a3d | 2021-06-30 18:51:42 -0700 | [diff] [blame] | 1575 | pmd = pmd_mkwrite(pmd); |
| 1576 | set_pmd_at(vma->vm_mm, haddr, vmf->pmd, pmd); |
| 1577 | update_mmu_cache_pmd(vma, vmf->address, vmf->pmd); |
| 1578 | spin_unlock(vmf->ptl); |
| 1579 | goto out; |
Mel Gorman | d10e63f | 2012-10-25 14:16:31 +0200 | [diff] [blame] | 1580 | } |
| 1581 | |
Huang Ying | 319904a | 2016-07-28 15:48:03 -0700 | [diff] [blame] | 1582 | /* |
| 1583 | * Return true if we do MADV_FREE successfully on entire pmd page. |
| 1584 | * Otherwise, return false. |
| 1585 | */ |
| 1586 | bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1587 | pmd_t *pmd, unsigned long addr, unsigned long next) |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1588 | { |
| 1589 | spinlock_t *ptl; |
| 1590 | pmd_t orig_pmd; |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1591 | struct folio *folio; |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1592 | struct mm_struct *mm = tlb->mm; |
Huang Ying | 319904a | 2016-07-28 15:48:03 -0700 | [diff] [blame] | 1593 | bool ret = false; |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1594 | |
Peter Zijlstra | ed6a793 | 2018-08-31 14:46:08 +0200 | [diff] [blame] | 1595 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
Aneesh Kumar K.V | 07e3266 | 2016-12-12 16:42:40 -0800 | [diff] [blame] | 1596 | |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1597 | ptl = pmd_trans_huge_lock(pmd, vma); |
| 1598 | if (!ptl) |
Linus Torvalds | 25eedab | 2016-01-17 18:33:15 -0800 | [diff] [blame] | 1599 | goto out_unlocked; |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1600 | |
| 1601 | orig_pmd = *pmd; |
Huang Ying | 319904a | 2016-07-28 15:48:03 -0700 | [diff] [blame] | 1602 | if (is_huge_zero_pmd(orig_pmd)) |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1603 | goto out; |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1604 | |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1605 | if (unlikely(!pmd_present(orig_pmd))) { |
| 1606 | VM_BUG_ON(thp_migration_supported() && |
| 1607 | !is_pmd_migration_entry(orig_pmd)); |
| 1608 | goto out; |
| 1609 | } |
| 1610 | |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1611 | folio = pfn_folio(pmd_pfn(orig_pmd)); |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1612 | /* |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1613 | * If other processes are mapping this folio, we couldn't discard |
| 1614 | * the folio unless they all do MADV_FREE so let's skip the folio. |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1615 | */ |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1616 | if (folio_mapcount(folio) != 1) |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1617 | goto out; |
| 1618 | |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1619 | if (!folio_trylock(folio)) |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1620 | goto out; |
| 1621 | |
| 1622 | /* |
| 1623 | * If user want to discard part-pages of THP, split it so MADV_FREE |
| 1624 | * will deactivate only them. |
| 1625 | */ |
| 1626 | if (next - addr != HPAGE_PMD_SIZE) { |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1627 | folio_get(folio); |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1628 | spin_unlock(ptl); |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1629 | split_folio(folio); |
| 1630 | folio_unlock(folio); |
| 1631 | folio_put(folio); |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1632 | goto out_unlocked; |
| 1633 | } |
| 1634 | |
Kefeng Wang | fc986a3 | 2022-12-07 10:34:30 +0800 | [diff] [blame] | 1635 | if (folio_test_dirty(folio)) |
| 1636 | folio_clear_dirty(folio); |
| 1637 | folio_unlock(folio); |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1638 | |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1639 | if (pmd_young(orig_pmd) || pmd_dirty(orig_pmd)) { |
Kirill A. Shutemov | 58ceeb6 | 2017-04-13 14:56:26 -0700 | [diff] [blame] | 1640 | pmdp_invalidate(vma, addr, pmd); |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1641 | orig_pmd = pmd_mkold(orig_pmd); |
| 1642 | orig_pmd = pmd_mkclean(orig_pmd); |
| 1643 | |
| 1644 | set_pmd_at(mm, addr, pmd, orig_pmd); |
| 1645 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); |
| 1646 | } |
Shaohua Li | 802a3a9 | 2017-05-03 14:52:32 -0700 | [diff] [blame] | 1647 | |
Kefeng Wang | 6a6fe9e | 2022-12-09 10:06:18 +0800 | [diff] [blame] | 1648 | folio_mark_lazyfree(folio); |
Huang Ying | 319904a | 2016-07-28 15:48:03 -0700 | [diff] [blame] | 1649 | ret = true; |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 1650 | out: |
| 1651 | spin_unlock(ptl); |
| 1652 | out_unlocked: |
| 1653 | return ret; |
| 1654 | } |
| 1655 | |
Aneesh Kumar K.V | 953c66c | 2016-12-12 16:44:32 -0800 | [diff] [blame] | 1656 | static inline void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd) |
| 1657 | { |
| 1658 | pgtable_t pgtable; |
| 1659 | |
| 1660 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); |
| 1661 | pte_free(mm, pgtable); |
Kirill A. Shutemov | c481290 | 2017-11-15 17:35:37 -0800 | [diff] [blame] | 1662 | mm_dec_nr_ptes(mm); |
Aneesh Kumar K.V | 953c66c | 2016-12-12 16:44:32 -0800 | [diff] [blame] | 1663 | } |
| 1664 | |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1665 | int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
Shaohua Li | f21760b | 2012-01-12 17:19:16 -0800 | [diff] [blame] | 1666 | pmd_t *pmd, unsigned long addr) |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1667 | { |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1668 | pmd_t orig_pmd; |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1669 | spinlock_t *ptl; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1670 | |
Peter Zijlstra | ed6a793 | 2018-08-31 14:46:08 +0200 | [diff] [blame] | 1671 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
Aneesh Kumar K.V | 07e3266 | 2016-12-12 16:42:40 -0800 | [diff] [blame] | 1672 | |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1673 | ptl = __pmd_trans_huge_lock(pmd, vma); |
| 1674 | if (!ptl) |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1675 | return 0; |
| 1676 | /* |
| 1677 | * For architectures like ppc64 we look at deposited pgtable |
| 1678 | * when calling pmdp_huge_get_and_clear. So do the |
| 1679 | * pgtable_trans_huge_withdraw after finishing pmdp related |
| 1680 | * operations. |
| 1681 | */ |
Aneesh Kumar K.V | 93a9869 | 2020-05-05 12:47:28 +0530 | [diff] [blame] | 1682 | orig_pmd = pmdp_huge_get_and_clear_full(vma, addr, pmd, |
| 1683 | tlb->fullmm); |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1684 | tlb_remove_pmd_tlb_entry(tlb, pmd, addr); |
Thomas Hellstrom (VMware) | 2484ca9 | 2020-03-24 18:47:17 +0100 | [diff] [blame] | 1685 | if (vma_is_special_huge(vma)) { |
Oliver O'Halloran | 3b6521f | 2017-05-08 15:59:43 -0700 | [diff] [blame] | 1686 | if (arch_needs_pgtable_deposit()) |
| 1687 | zap_deposited_table(tlb->mm, pmd); |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1688 | spin_unlock(ptl); |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1689 | } else if (is_huge_zero_pmd(orig_pmd)) { |
Oliver O'Halloran | c14a6eb | 2017-05-08 15:59:40 -0700 | [diff] [blame] | 1690 | zap_deposited_table(tlb->mm, pmd); |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1691 | spin_unlock(ptl); |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1692 | } else { |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 1693 | struct page *page = NULL; |
| 1694 | int flush_needed = 1; |
| 1695 | |
| 1696 | if (pmd_present(orig_pmd)) { |
| 1697 | page = pmd_page(orig_pmd); |
Hugh Dickins | cea86fe | 2022-02-14 18:26:39 -0800 | [diff] [blame] | 1698 | page_remove_rmap(page, vma, true); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 1699 | VM_BUG_ON_PAGE(page_mapcount(page) < 0, page); |
| 1700 | VM_BUG_ON_PAGE(!PageHead(page), page); |
| 1701 | } else if (thp_migration_supported()) { |
| 1702 | swp_entry_t entry; |
| 1703 | |
| 1704 | VM_BUG_ON(!is_pmd_migration_entry(orig_pmd)); |
| 1705 | entry = pmd_to_swp_entry(orig_pmd); |
Alistair Popple | af5cdaf | 2021-06-30 18:54:06 -0700 | [diff] [blame] | 1706 | page = pfn_swap_entry_to_page(entry); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 1707 | flush_needed = 0; |
| 1708 | } else |
| 1709 | WARN_ONCE(1, "Non present huge pmd without pmd migration enabled!"); |
| 1710 | |
Kirill A. Shutemov | b507238 | 2016-07-26 15:25:34 -0700 | [diff] [blame] | 1711 | if (PageAnon(page)) { |
Oliver O'Halloran | c14a6eb | 2017-05-08 15:59:40 -0700 | [diff] [blame] | 1712 | zap_deposited_table(tlb->mm, pmd); |
Kirill A. Shutemov | b507238 | 2016-07-26 15:25:34 -0700 | [diff] [blame] | 1713 | add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR); |
| 1714 | } else { |
Aneesh Kumar K.V | 953c66c | 2016-12-12 16:44:32 -0800 | [diff] [blame] | 1715 | if (arch_needs_pgtable_deposit()) |
| 1716 | zap_deposited_table(tlb->mm, pmd); |
Yang Shi | fadae29 | 2018-08-17 15:44:55 -0700 | [diff] [blame] | 1717 | add_mm_counter(tlb->mm, mm_counter_file(page), -HPAGE_PMD_NR); |
Kirill A. Shutemov | b507238 | 2016-07-26 15:25:34 -0700 | [diff] [blame] | 1718 | } |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 1719 | |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1720 | spin_unlock(ptl); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 1721 | if (flush_needed) |
| 1722 | tlb_remove_page_size(tlb, page, HPAGE_PMD_SIZE); |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1723 | } |
Kirill A. Shutemov | da14676 | 2015-09-08 14:59:31 -0700 | [diff] [blame] | 1724 | return 1; |
Andrea Arcangeli | 71e3aac | 2011-01-13 15:46:52 -0800 | [diff] [blame] | 1725 | } |
| 1726 | |
Aneesh Kumar K.V | 1dd38b6 | 2016-12-12 16:44:29 -0800 | [diff] [blame] | 1727 | #ifndef pmd_move_must_withdraw |
| 1728 | static inline int pmd_move_must_withdraw(spinlock_t *new_pmd_ptl, |
| 1729 | spinlock_t *old_pmd_ptl, |
| 1730 | struct vm_area_struct *vma) |
| 1731 | { |
| 1732 | /* |
| 1733 | * With split pmd lock we also need to move preallocated |
| 1734 | * PTE page table if new_pmd is on different PMD page table. |
| 1735 | * |
| 1736 | * We also don't deposit and withdraw tables for file pages. |
| 1737 | */ |
| 1738 | return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma); |
| 1739 | } |
| 1740 | #endif |
| 1741 | |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 1742 | static pmd_t move_soft_dirty_pmd(pmd_t pmd) |
| 1743 | { |
| 1744 | #ifdef CONFIG_MEM_SOFT_DIRTY |
| 1745 | if (unlikely(is_pmd_migration_entry(pmd))) |
| 1746 | pmd = pmd_swp_mksoft_dirty(pmd); |
| 1747 | else if (pmd_present(pmd)) |
| 1748 | pmd = pmd_mksoft_dirty(pmd); |
| 1749 | #endif |
| 1750 | return pmd; |
| 1751 | } |
| 1752 | |
Hugh Dickins | bf8616d | 2016-05-19 17:12:54 -0700 | [diff] [blame] | 1753 | bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr, |
Wei Yang | b8aa9d9 | 2020-08-06 23:23:40 -0700 | [diff] [blame] | 1754 | unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd) |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1755 | { |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1756 | spinlock_t *old_ptl, *new_ptl; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1757 | pmd_t pmd; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1758 | struct mm_struct *mm = vma->vm_mm; |
Aaron Lu | 5d19042 | 2016-11-10 17:16:33 +0800 | [diff] [blame] | 1759 | bool force_flush = false; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1760 | |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1761 | /* |
| 1762 | * The destination pmd shouldn't be established, free_pgtables() |
| 1763 | * should have release it. |
| 1764 | */ |
| 1765 | if (WARN_ON(!pmd_none(*new_pmd))) { |
| 1766 | VM_BUG_ON(pmd_trans_huge(*new_pmd)); |
Kirill A. Shutemov | 4b471e8 | 2016-01-15 16:53:39 -0800 | [diff] [blame] | 1767 | return false; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1768 | } |
| 1769 | |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1770 | /* |
| 1771 | * We don't have to worry about the ordering of src and dst |
Michel Lespinasse | c1e8d7c | 2020-06-08 21:33:54 -0700 | [diff] [blame] | 1772 | * ptlocks because exclusive mmap_lock prevents deadlock. |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1773 | */ |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1774 | old_ptl = __pmd_trans_huge_lock(old_pmd, vma); |
| 1775 | if (old_ptl) { |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1776 | new_ptl = pmd_lockptr(mm, new_pmd); |
| 1777 | if (new_ptl != old_ptl) |
| 1778 | spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING); |
Aneesh Kumar K.V | 8809aa2 | 2015-06-24 16:57:44 -0700 | [diff] [blame] | 1779 | pmd = pmdp_huge_get_and_clear(mm, old_addr, old_pmd); |
Linus Torvalds | eb66ae0 | 2018-10-12 15:22:59 -0700 | [diff] [blame] | 1780 | if (pmd_present(pmd)) |
Aaron Lu | a2ce266 | 2016-11-29 13:27:31 +0800 | [diff] [blame] | 1781 | force_flush = true; |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1782 | VM_BUG_ON(!pmd_none(*new_pmd)); |
Kirill A. Shutemov | 3592806 | 2013-12-12 17:12:33 -0800 | [diff] [blame] | 1783 | |
Aneesh Kumar K.V | 1dd38b6 | 2016-12-12 16:44:29 -0800 | [diff] [blame] | 1784 | if (pmd_move_must_withdraw(new_ptl, old_ptl, vma)) { |
Aneesh Kumar K.V | b3084f4 | 2014-01-13 11:34:24 +0530 | [diff] [blame] | 1785 | pgtable_t pgtable; |
Kirill A. Shutemov | 3592806 | 2013-12-12 17:12:33 -0800 | [diff] [blame] | 1786 | pgtable = pgtable_trans_huge_withdraw(mm, old_pmd); |
| 1787 | pgtable_trans_huge_deposit(mm, new_pmd, pgtable); |
Kirill A. Shutemov | 3592806 | 2013-12-12 17:12:33 -0800 | [diff] [blame] | 1788 | } |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 1789 | pmd = move_soft_dirty_pmd(pmd); |
| 1790 | set_pmd_at(mm, new_addr, new_pmd, pmd); |
Aaron Lu | 5d19042 | 2016-11-10 17:16:33 +0800 | [diff] [blame] | 1791 | if (force_flush) |
Miaohe Lin | 7c38f18 | 2022-07-04 21:21:46 +0800 | [diff] [blame] | 1792 | flush_pmd_tlb_range(vma, old_addr, old_addr + PMD_SIZE); |
Linus Torvalds | eb66ae0 | 2018-10-12 15:22:59 -0700 | [diff] [blame] | 1793 | if (new_ptl != old_ptl) |
| 1794 | spin_unlock(new_ptl); |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1795 | spin_unlock(old_ptl); |
Kirill A. Shutemov | 4b471e8 | 2016-01-15 16:53:39 -0800 | [diff] [blame] | 1796 | return true; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1797 | } |
Kirill A. Shutemov | 4b471e8 | 2016-01-15 16:53:39 -0800 | [diff] [blame] | 1798 | return false; |
Andrea Arcangeli | 37a1c49 | 2011-10-31 17:08:30 -0700 | [diff] [blame] | 1799 | } |
| 1800 | |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 1801 | /* |
| 1802 | * Returns |
| 1803 | * - 0 if PMD could not be locked |
Ingo Molnar | f0953a1 | 2021-05-06 18:06:47 -0700 | [diff] [blame] | 1804 | * - 1 if PMD was locked but protections unchanged and TLB flush unnecessary |
Yang Shi | e346e66 | 2021-06-30 18:51:55 -0700 | [diff] [blame] | 1805 | * or if prot_numa but THP migration is not supported |
Ingo Molnar | f0953a1 | 2021-05-06 18:06:47 -0700 | [diff] [blame] | 1806 | * - HPAGE_PMD_NR if protections changed and TLB flush necessary |
Mel Gorman | f123d74 | 2013-10-07 11:28:49 +0100 | [diff] [blame] | 1807 | */ |
Nadav Amit | 4a18419 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1808 | int change_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma, |
| 1809 | pmd_t *pmd, unsigned long addr, pgprot_t newprot, |
| 1810 | unsigned long cp_flags) |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 1811 | { |
| 1812 | struct mm_struct *mm = vma->vm_mm; |
Kirill A. Shutemov | bf92915 | 2013-11-14 14:30:54 -0800 | [diff] [blame] | 1813 | spinlock_t *ptl; |
Nadav Amit | c9fe665 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1814 | pmd_t oldpmd, entry; |
Peter Xu | 5870544 | 2020-04-06 20:05:45 -0700 | [diff] [blame] | 1815 | bool prot_numa = cp_flags & MM_CP_PROT_NUMA; |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 1816 | bool uffd_wp = cp_flags & MM_CP_UFFD_WP; |
| 1817 | bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; |
David Hildenbrand | 6a56ccb | 2022-11-08 18:46:50 +0100 | [diff] [blame] | 1818 | int ret = 1; |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 1819 | |
Nadav Amit | 4a18419 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1820 | tlb_change_page_size(tlb, HPAGE_PMD_SIZE); |
| 1821 | |
Yang Shi | e346e66 | 2021-06-30 18:51:55 -0700 | [diff] [blame] | 1822 | if (prot_numa && !thp_migration_supported()) |
| 1823 | return 1; |
| 1824 | |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1825 | ptl = __pmd_trans_huge_lock(pmd, vma); |
Kirill A. Shutemov | 0a85e51d | 2017-04-13 14:56:17 -0700 | [diff] [blame] | 1826 | if (!ptl) |
| 1827 | return 0; |
Mel Gorman | e944fd6 | 2015-02-12 14:58:35 -0800 | [diff] [blame] | 1828 | |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1829 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION |
| 1830 | if (is_swap_pmd(*pmd)) { |
| 1831 | swp_entry_t entry = pmd_to_swp_entry(*pmd); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1832 | struct page *page = pfn_swap_entry_to_page(entry); |
David Hildenbrand | 24bf08c | 2023-04-05 18:02:35 +0200 | [diff] [blame] | 1833 | pmd_t newpmd; |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1834 | |
| 1835 | VM_BUG_ON(!is_pmd_migration_entry(*pmd)); |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 1836 | if (is_writable_migration_entry(entry)) { |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1837 | /* |
| 1838 | * A protection check is difficult so |
| 1839 | * just be safe and disable write |
| 1840 | */ |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 1841 | if (PageAnon(page)) |
| 1842 | entry = make_readable_exclusive_migration_entry(swp_offset(entry)); |
| 1843 | else |
| 1844 | entry = make_readable_migration_entry(swp_offset(entry)); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1845 | newpmd = swp_entry_to_pmd(entry); |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 1846 | if (pmd_swp_soft_dirty(*pmd)) |
| 1847 | newpmd = pmd_swp_mksoft_dirty(newpmd); |
David Hildenbrand | 24bf08c | 2023-04-05 18:02:35 +0200 | [diff] [blame] | 1848 | } else { |
| 1849 | newpmd = *pmd; |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1850 | } |
David Hildenbrand | 24bf08c | 2023-04-05 18:02:35 +0200 | [diff] [blame] | 1851 | |
| 1852 | if (uffd_wp) |
| 1853 | newpmd = pmd_swp_mkuffd_wp(newpmd); |
| 1854 | else if (uffd_wp_resolve) |
| 1855 | newpmd = pmd_swp_clear_uffd_wp(newpmd); |
| 1856 | if (!pmd_same(*pmd, newpmd)) |
| 1857 | set_pmd_at(mm, addr, pmd, newpmd); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1858 | goto unlock; |
| 1859 | } |
| 1860 | #endif |
| 1861 | |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1862 | if (prot_numa) { |
| 1863 | struct page *page; |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1864 | bool toptier; |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1865 | /* |
| 1866 | * Avoid trapping faults against the zero page. The read-only |
| 1867 | * data is likely to be read-cached on the local CPU and |
| 1868 | * local/remote hits to the zero page are not interesting. |
| 1869 | */ |
| 1870 | if (is_huge_zero_pmd(*pmd)) |
| 1871 | goto unlock; |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 1872 | |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1873 | if (pmd_protnone(*pmd)) |
| 1874 | goto unlock; |
Kirill A. Shutemov | 0a85e51d | 2017-04-13 14:56:17 -0700 | [diff] [blame] | 1875 | |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1876 | page = pmd_page(*pmd); |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1877 | toptier = node_is_toptier(page_to_nid(page)); |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1878 | /* |
| 1879 | * Skip scanning top tier node if normal numa |
| 1880 | * balancing is disabled |
| 1881 | */ |
| 1882 | if (!(sysctl_numa_balancing_mode & NUMA_BALANCING_NORMAL) && |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1883 | toptier) |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1884 | goto unlock; |
Huang Ying | 3302453 | 2022-07-13 16:39:51 +0800 | [diff] [blame] | 1885 | |
| 1886 | if (sysctl_numa_balancing_mode & NUMA_BALANCING_MEMORY_TIERING && |
| 1887 | !toptier) |
| 1888 | xchg_page_access_time(page, jiffies_to_msecs(jiffies)); |
Huang Ying | a1a3a2f | 2022-03-22 14:46:27 -0700 | [diff] [blame] | 1889 | } |
Kirill A. Shutemov | ced1080 | 2017-04-13 14:56:20 -0700 | [diff] [blame] | 1890 | /* |
Michel Lespinasse | 3e4e28c | 2020-06-08 21:33:51 -0700 | [diff] [blame] | 1891 | * In case prot_numa, we are under mmap_read_lock(mm). It's critical |
Kirill A. Shutemov | ced1080 | 2017-04-13 14:56:20 -0700 | [diff] [blame] | 1892 | * to not clear pmd intermittently to avoid race with MADV_DONTNEED |
Michel Lespinasse | 3e4e28c | 2020-06-08 21:33:51 -0700 | [diff] [blame] | 1893 | * which is also under mmap_read_lock(mm): |
Kirill A. Shutemov | ced1080 | 2017-04-13 14:56:20 -0700 | [diff] [blame] | 1894 | * |
| 1895 | * CPU0: CPU1: |
| 1896 | * change_huge_pmd(prot_numa=1) |
| 1897 | * pmdp_huge_get_and_clear_notify() |
| 1898 | * madvise_dontneed() |
| 1899 | * zap_pmd_range() |
| 1900 | * pmd_trans_huge(*pmd) == 0 (without ptl) |
| 1901 | * // skip the pmd |
| 1902 | * set_pmd_at(); |
| 1903 | * // pmd is re-established |
| 1904 | * |
| 1905 | * The race makes MADV_DONTNEED miss the huge pmd and don't clear it |
| 1906 | * which may break userspace. |
| 1907 | * |
Nadav Amit | 4f83145 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1908 | * pmdp_invalidate_ad() is required to make sure we don't miss |
Kirill A. Shutemov | ced1080 | 2017-04-13 14:56:20 -0700 | [diff] [blame] | 1909 | * dirty/young flags set by hardware. |
| 1910 | */ |
Nadav Amit | 4f83145 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1911 | oldpmd = pmdp_invalidate_ad(vma, addr, pmd); |
Kirill A. Shutemov | ced1080 | 2017-04-13 14:56:20 -0700 | [diff] [blame] | 1912 | |
Nadav Amit | c9fe665 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1913 | entry = pmd_modify(oldpmd, newprot); |
Peter Xu | f1eb1ba | 2022-12-14 15:15:33 -0500 | [diff] [blame] | 1914 | if (uffd_wp) |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 1915 | entry = pmd_mkuffd_wp(entry); |
Peter Xu | f1eb1ba | 2022-12-14 15:15:33 -0500 | [diff] [blame] | 1916 | else if (uffd_wp_resolve) |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 1917 | /* |
| 1918 | * Leave the write bit to be handled by PF interrupt |
| 1919 | * handler, then things like COW could be properly |
| 1920 | * handled. |
| 1921 | */ |
| 1922 | entry = pmd_clear_uffd_wp(entry); |
David Hildenbrand | c27f479 | 2022-11-08 18:46:48 +0100 | [diff] [blame] | 1923 | |
| 1924 | /* See change_pte_range(). */ |
| 1925 | if ((cp_flags & MM_CP_TRY_CHANGE_WRITABLE) && !pmd_write(entry) && |
| 1926 | can_change_pmd_writable(vma, addr, entry)) |
| 1927 | entry = pmd_mkwrite(entry); |
| 1928 | |
Kirill A. Shutemov | 0a85e51d | 2017-04-13 14:56:17 -0700 | [diff] [blame] | 1929 | ret = HPAGE_PMD_NR; |
| 1930 | set_pmd_at(mm, addr, pmd, entry); |
Nadav Amit | 4a18419 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1931 | |
Nadav Amit | c9fe665 | 2022-05-09 18:20:50 -0700 | [diff] [blame] | 1932 | if (huge_pmd_needs_flush(oldpmd, entry)) |
| 1933 | tlb_flush_pmd_range(tlb, addr, HPAGE_PMD_SIZE); |
Kirill A. Shutemov | 0a85e51d | 2017-04-13 14:56:17 -0700 | [diff] [blame] | 1934 | unlock: |
| 1935 | spin_unlock(ptl); |
Johannes Weiner | cd7548a | 2011-01-13 15:47:04 -0800 | [diff] [blame] | 1936 | return ret; |
| 1937 | } |
| 1938 | |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1939 | /* |
Huang Ying | 8f19b0c | 2016-07-26 15:27:04 -0700 | [diff] [blame] | 1940 | * Returns page table lock pointer if a given pmd maps a thp, NULL otherwise. |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1941 | * |
Huang Ying | 8f19b0c | 2016-07-26 15:27:04 -0700 | [diff] [blame] | 1942 | * Note that if it returns page table lock pointer, this routine returns without |
| 1943 | * unlocking page table lock. So callers must unlock it. |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1944 | */ |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1945 | spinlock_t *__pmd_trans_huge_lock(pmd_t *pmd, struct vm_area_struct *vma) |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1946 | { |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1947 | spinlock_t *ptl; |
| 1948 | ptl = pmd_lock(vma->vm_mm, pmd); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 1949 | if (likely(is_swap_pmd(*pmd) || pmd_trans_huge(*pmd) || |
| 1950 | pmd_devmap(*pmd))) |
Kirill A. Shutemov | b6ec57f | 2016-01-21 16:40:25 -0800 | [diff] [blame] | 1951 | return ptl; |
| 1952 | spin_unlock(ptl); |
| 1953 | return NULL; |
Naoya Horiguchi | 025c5b2 | 2012-03-21 16:33:57 -0700 | [diff] [blame] | 1954 | } |
| 1955 | |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1956 | /* |
Miaohe Lin | d965e39 | 2022-07-04 21:21:48 +0800 | [diff] [blame] | 1957 | * Returns page table lock pointer if a given pud maps a thp, NULL otherwise. |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1958 | * |
Miaohe Lin | d965e39 | 2022-07-04 21:21:48 +0800 | [diff] [blame] | 1959 | * Note that if it returns page table lock pointer, this routine returns without |
| 1960 | * unlocking page table lock. So callers must unlock it. |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1961 | */ |
| 1962 | spinlock_t *__pud_trans_huge_lock(pud_t *pud, struct vm_area_struct *vma) |
| 1963 | { |
| 1964 | spinlock_t *ptl; |
| 1965 | |
| 1966 | ptl = pud_lock(vma->vm_mm, pud); |
| 1967 | if (likely(pud_trans_huge(*pud) || pud_devmap(*pud))) |
| 1968 | return ptl; |
| 1969 | spin_unlock(ptl); |
| 1970 | return NULL; |
| 1971 | } |
| 1972 | |
| 1973 | #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
| 1974 | int zap_huge_pud(struct mmu_gather *tlb, struct vm_area_struct *vma, |
| 1975 | pud_t *pud, unsigned long addr) |
| 1976 | { |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1977 | spinlock_t *ptl; |
| 1978 | |
| 1979 | ptl = __pud_trans_huge_lock(pud, vma); |
| 1980 | if (!ptl) |
| 1981 | return 0; |
Miaohe Lin | 7492907 | 2022-07-04 21:21:54 +0800 | [diff] [blame] | 1982 | |
Qian Cai | 70516b9 | 2019-03-05 15:50:00 -0800 | [diff] [blame] | 1983 | pudp_huge_get_and_clear_full(tlb->mm, addr, pud, tlb->fullmm); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1984 | tlb_remove_pud_tlb_entry(tlb, pud, addr); |
Thomas Hellstrom (VMware) | 2484ca9 | 2020-03-24 18:47:17 +0100 | [diff] [blame] | 1985 | if (vma_is_special_huge(vma)) { |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 1986 | spin_unlock(ptl); |
| 1987 | /* No zero page support yet */ |
| 1988 | } else { |
| 1989 | /* No support for anonymous PUD pages yet */ |
| 1990 | BUG(); |
| 1991 | } |
| 1992 | return 1; |
| 1993 | } |
| 1994 | |
| 1995 | static void __split_huge_pud_locked(struct vm_area_struct *vma, pud_t *pud, |
| 1996 | unsigned long haddr) |
| 1997 | { |
| 1998 | VM_BUG_ON(haddr & ~HPAGE_PUD_MASK); |
| 1999 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); |
| 2000 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PUD_SIZE, vma); |
| 2001 | VM_BUG_ON(!pud_trans_huge(*pud) && !pud_devmap(*pud)); |
| 2002 | |
Yisheng Xie | ce9311c | 2017-03-09 16:17:00 -0800 | [diff] [blame] | 2003 | count_vm_event(THP_SPLIT_PUD); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 2004 | |
| 2005 | pudp_huge_clear_flush_notify(vma, haddr, pud); |
| 2006 | } |
| 2007 | |
| 2008 | void __split_huge_pud(struct vm_area_struct *vma, pud_t *pud, |
| 2009 | unsigned long address) |
| 2010 | { |
| 2011 | spinlock_t *ptl; |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2012 | struct mmu_notifier_range range; |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 2013 | |
Alistair Popple | 7d4a8be | 2023-01-10 13:57:22 +1100 | [diff] [blame] | 2014 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
Jérôme Glisse | 6f4f13e | 2019-05-13 17:20:49 -0700 | [diff] [blame] | 2015 | address & HPAGE_PUD_MASK, |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2016 | (address & HPAGE_PUD_MASK) + HPAGE_PUD_SIZE); |
| 2017 | mmu_notifier_invalidate_range_start(&range); |
| 2018 | ptl = pud_lock(vma->vm_mm, pud); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 2019 | if (unlikely(!pud_trans_huge(*pud) && !pud_devmap(*pud))) |
| 2020 | goto out; |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2021 | __split_huge_pud_locked(vma, pud, range.start); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 2022 | |
| 2023 | out: |
| 2024 | spin_unlock(ptl); |
Jérôme Glisse | 4645b9f | 2017-11-15 17:34:11 -0800 | [diff] [blame] | 2025 | /* |
| 2026 | * No need to double call mmu_notifier->invalidate_range() callback as |
| 2027 | * the above pudp_huge_clear_flush_notify() did already call it. |
| 2028 | */ |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2029 | mmu_notifier_invalidate_range_only_end(&range); |
Matthew Wilcox | a00cc7d | 2017-02-24 14:57:02 -0800 | [diff] [blame] | 2030 | } |
| 2031 | #endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
| 2032 | |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2033 | static void __split_huge_zero_page_pmd(struct vm_area_struct *vma, |
| 2034 | unsigned long haddr, pmd_t *pmd) |
| 2035 | { |
| 2036 | struct mm_struct *mm = vma->vm_mm; |
| 2037 | pgtable_t pgtable; |
David Hildenbrand | 42b2af2 | 2023-03-02 18:54:23 +0100 | [diff] [blame] | 2038 | pmd_t _pmd, old_pmd; |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2039 | int i; |
| 2040 | |
Jérôme Glisse | 0f10851 | 2017-11-15 17:34:07 -0800 | [diff] [blame] | 2041 | /* |
| 2042 | * Leave pmd empty until pte is filled note that it is fine to delay |
| 2043 | * notification until mmu_notifier_invalidate_range_end() as we are |
| 2044 | * replacing a zero pmd write protected page with a zero pte write |
| 2045 | * protected page. |
| 2046 | * |
Mike Rapoport | ee65728 | 2022-06-27 09:00:26 +0300 | [diff] [blame] | 2047 | * See Documentation/mm/mmu_notifier.rst |
Jérôme Glisse | 0f10851 | 2017-11-15 17:34:07 -0800 | [diff] [blame] | 2048 | */ |
David Hildenbrand | 42b2af2 | 2023-03-02 18:54:23 +0100 | [diff] [blame] | 2049 | old_pmd = pmdp_huge_clear_flush(vma, haddr, pmd); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2050 | |
| 2051 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); |
| 2052 | pmd_populate(mm, &_pmd, pgtable); |
| 2053 | |
| 2054 | for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) { |
| 2055 | pte_t *pte, entry; |
| 2056 | entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot); |
| 2057 | entry = pte_mkspecial(entry); |
David Hildenbrand | 42b2af2 | 2023-03-02 18:54:23 +0100 | [diff] [blame] | 2058 | if (pmd_uffd_wp(old_pmd)) |
| 2059 | entry = pte_mkuffd_wp(entry); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2060 | pte = pte_offset_map(&_pmd, haddr); |
| 2061 | VM_BUG_ON(!pte_none(*pte)); |
| 2062 | set_pte_at(mm, haddr, pte, entry); |
| 2063 | pte_unmap(pte); |
| 2064 | } |
| 2065 | smp_wmb(); /* make pte visible before pmd */ |
| 2066 | pmd_populate(mm, pmd, pgtable); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2067 | } |
| 2068 | |
| 2069 | static void __split_huge_pmd_locked(struct vm_area_struct *vma, pmd_t *pmd, |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2070 | unsigned long haddr, bool freeze) |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2071 | { |
| 2072 | struct mm_struct *mm = vma->vm_mm; |
| 2073 | struct page *page; |
| 2074 | pgtable_t pgtable; |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2075 | pmd_t old_pmd, _pmd; |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 2076 | bool young, write, soft_dirty, pmd_migration = false, uffd_wp = false; |
Peter Xu | 0ccf7f1 | 2022-08-11 12:13:28 -0400 | [diff] [blame] | 2077 | bool anon_exclusive = false, dirty = false; |
Kirill A. Shutemov | 2ac015e | 2016-02-24 18:58:03 +0300 | [diff] [blame] | 2078 | unsigned long addr; |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2079 | int i; |
| 2080 | |
| 2081 | VM_BUG_ON(haddr & ~HPAGE_PMD_MASK); |
| 2082 | VM_BUG_ON_VMA(vma->vm_start > haddr, vma); |
| 2083 | VM_BUG_ON_VMA(vma->vm_end < haddr + HPAGE_PMD_SIZE, vma); |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 2084 | VM_BUG_ON(!is_pmd_migration_entry(*pmd) && !pmd_trans_huge(*pmd) |
| 2085 | && !pmd_devmap(*pmd)); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2086 | |
| 2087 | count_vm_event(THP_SPLIT_PMD); |
| 2088 | |
Kirill A. Shutemov | d21b9e5 | 2016-07-26 15:25:37 -0700 | [diff] [blame] | 2089 | if (!vma_is_anonymous(vma)) { |
Hugh Dickins | 99fa8a4 | 2021-06-15 18:23:45 -0700 | [diff] [blame] | 2090 | old_pmd = pmdp_huge_clear_flush_notify(vma, haddr, pmd); |
Aneesh Kumar K.V | 953c66c | 2016-12-12 16:44:32 -0800 | [diff] [blame] | 2091 | /* |
| 2092 | * We are going to unmap this huge page. So |
| 2093 | * just go ahead and zap it |
| 2094 | */ |
| 2095 | if (arch_needs_pgtable_deposit()) |
| 2096 | zap_deposited_table(mm, pmd); |
Thomas Hellstrom (VMware) | 2484ca9 | 2020-03-24 18:47:17 +0100 | [diff] [blame] | 2097 | if (vma_is_special_huge(vma)) |
Kirill A. Shutemov | d21b9e5 | 2016-07-26 15:25:37 -0700 | [diff] [blame] | 2098 | return; |
Hugh Dickins | 99fa8a4 | 2021-06-15 18:23:45 -0700 | [diff] [blame] | 2099 | if (unlikely(is_pmd_migration_entry(old_pmd))) { |
| 2100 | swp_entry_t entry; |
| 2101 | |
| 2102 | entry = pmd_to_swp_entry(old_pmd); |
Alistair Popple | af5cdaf | 2021-06-30 18:54:06 -0700 | [diff] [blame] | 2103 | page = pfn_swap_entry_to_page(entry); |
Hugh Dickins | 99fa8a4 | 2021-06-15 18:23:45 -0700 | [diff] [blame] | 2104 | } else { |
| 2105 | page = pmd_page(old_pmd); |
| 2106 | if (!PageDirty(page) && pmd_dirty(old_pmd)) |
| 2107 | set_page_dirty(page); |
| 2108 | if (!PageReferenced(page) && pmd_young(old_pmd)) |
| 2109 | SetPageReferenced(page); |
Hugh Dickins | cea86fe | 2022-02-14 18:26:39 -0800 | [diff] [blame] | 2110 | page_remove_rmap(page, vma, true); |
Hugh Dickins | 99fa8a4 | 2021-06-15 18:23:45 -0700 | [diff] [blame] | 2111 | put_page(page); |
| 2112 | } |
Yang Shi | fadae29 | 2018-08-17 15:44:55 -0700 | [diff] [blame] | 2113 | add_mm_counter(mm, mm_counter_file(page), -HPAGE_PMD_NR); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2114 | return; |
Hugh Dickins | 99fa8a4 | 2021-06-15 18:23:45 -0700 | [diff] [blame] | 2115 | } |
| 2116 | |
Hugh Dickins | 3b77e8c | 2021-06-15 18:23:49 -0700 | [diff] [blame] | 2117 | if (is_huge_zero_pmd(*pmd)) { |
Jérôme Glisse | 4645b9f | 2017-11-15 17:34:11 -0800 | [diff] [blame] | 2118 | /* |
| 2119 | * FIXME: Do we want to invalidate secondary mmu by calling |
| 2120 | * mmu_notifier_invalidate_range() see comments below inside |
| 2121 | * __split_huge_pmd() ? |
| 2122 | * |
| 2123 | * We are going from a zero huge page write protected to zero |
| 2124 | * small page also write protected so it does not seems useful |
| 2125 | * to invalidate secondary mmu at this time. |
| 2126 | */ |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2127 | return __split_huge_zero_page_pmd(vma, haddr, pmd); |
| 2128 | } |
| 2129 | |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2130 | /* |
| 2131 | * Up to this point the pmd is present and huge and userland has the |
| 2132 | * whole access to the hugepage during the split (which happens in |
| 2133 | * place). If we overwrite the pmd with the not-huge version pointing |
| 2134 | * to the pte here (which of course we could if all CPUs were bug |
| 2135 | * free), userland could trigger a small page size TLB miss on the |
| 2136 | * small sized TLB while the hugepage TLB entry is still established in |
| 2137 | * the huge TLB. Some CPU doesn't like that. |
Alexander A. Klimov | 42742d9 | 2020-08-06 23:26:08 -0700 | [diff] [blame] | 2138 | * See http://support.amd.com/TechDocs/41322_10h_Rev_Gd.pdf, Erratum |
| 2139 | * 383 on page 105. Intel should be safe but is also warns that it's |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2140 | * only safe if the permission and cache attributes of the two entries |
| 2141 | * loaded in the two TLB is identical (which should be the case here). |
| 2142 | * But it is generally safer to never allow small and huge TLB entries |
| 2143 | * for the same virtual address to be loaded simultaneously. So instead |
| 2144 | * of doing "pmd_populate(); flush_pmd_tlb_range();" we first mark the |
| 2145 | * current pmd notpresent (atomically because here the pmd_trans_huge |
| 2146 | * must remain set at all times on the pmd until the split is complete |
| 2147 | * for this pmd), then we flush the SMP TLB and finally we write the |
| 2148 | * non-huge version of the pmd entry with pmd_populate. |
| 2149 | */ |
| 2150 | old_pmd = pmdp_invalidate(vma, haddr, pmd); |
| 2151 | |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2152 | pmd_migration = is_pmd_migration_entry(old_pmd); |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2153 | if (unlikely(pmd_migration)) { |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 2154 | swp_entry_t entry; |
| 2155 | |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2156 | entry = pmd_to_swp_entry(old_pmd); |
Alistair Popple | af5cdaf | 2021-06-30 18:54:06 -0700 | [diff] [blame] | 2157 | page = pfn_swap_entry_to_page(entry); |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 2158 | write = is_writable_migration_entry(entry); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2159 | if (PageAnon(page)) |
| 2160 | anon_exclusive = is_readable_exclusive_migration_entry(entry); |
Peter Xu | 2e34687 | 2022-08-11 12:13:29 -0400 | [diff] [blame] | 2161 | young = is_migration_entry_young(entry); |
| 2162 | dirty = is_migration_entry_dirty(entry); |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2163 | soft_dirty = pmd_swp_soft_dirty(old_pmd); |
Peter Xu | f45ec5f | 2020-04-06 20:06:01 -0700 | [diff] [blame] | 2164 | uffd_wp = pmd_swp_uffd_wp(old_pmd); |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2165 | } else { |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2166 | page = pmd_page(old_pmd); |
Peter Xu | 0ccf7f1 | 2022-08-11 12:13:28 -0400 | [diff] [blame] | 2167 | if (pmd_dirty(old_pmd)) { |
| 2168 | dirty = true; |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2169 | SetPageDirty(page); |
Peter Xu | 0ccf7f1 | 2022-08-11 12:13:28 -0400 | [diff] [blame] | 2170 | } |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2171 | write = pmd_write(old_pmd); |
| 2172 | young = pmd_young(old_pmd); |
| 2173 | soft_dirty = pmd_soft_dirty(old_pmd); |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 2174 | uffd_wp = pmd_uffd_wp(old_pmd); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2175 | |
Hugh Dickins | 9d84604 | 2022-03-22 14:46:11 -0700 | [diff] [blame] | 2176 | VM_BUG_ON_PAGE(!page_count(page), page); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2177 | |
| 2178 | /* |
| 2179 | * Without "freeze", we'll simply split the PMD, propagating the |
| 2180 | * PageAnonExclusive() flag for each PTE by setting it for |
| 2181 | * each subpage -- no need to (temporarily) clear. |
| 2182 | * |
| 2183 | * With "freeze" we want to replace mapped pages by |
| 2184 | * migration entries right away. This is only possible if we |
| 2185 | * managed to clear PageAnonExclusive() -- see |
| 2186 | * set_pmd_migration_entry(). |
| 2187 | * |
| 2188 | * In case we cannot clear PageAnonExclusive(), split the PMD |
| 2189 | * only and let try_to_migrate_one() fail later. |
David Hildenbrand | 088b8aa | 2022-09-01 10:35:59 +0200 | [diff] [blame] | 2190 | * |
| 2191 | * See page_try_share_anon_rmap(): invalidate PMD first. |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2192 | */ |
| 2193 | anon_exclusive = PageAnon(page) && PageAnonExclusive(page); |
| 2194 | if (freeze && anon_exclusive && page_try_share_anon_rmap(page)) |
| 2195 | freeze = false; |
Hugh Dickins | 96d82de | 2022-11-22 01:51:50 -0800 | [diff] [blame] | 2196 | if (!freeze) |
| 2197 | page_ref_add(page, HPAGE_PMD_NR - 1); |
Peter Xu | 2e83ee1 | 2018-12-21 14:30:50 -0800 | [diff] [blame] | 2198 | } |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2199 | |
Aneesh Kumar K.V | 423ac9a | 2018-01-31 16:18:24 -0800 | [diff] [blame] | 2200 | /* |
| 2201 | * Withdraw the table only after we mark the pmd entry invalid. |
| 2202 | * This's critical for some architectures (Power). |
| 2203 | */ |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2204 | pgtable = pgtable_trans_huge_withdraw(mm, pmd); |
| 2205 | pmd_populate(mm, &_pmd, pgtable); |
| 2206 | |
Kirill A. Shutemov | 2ac015e | 2016-02-24 18:58:03 +0300 | [diff] [blame] | 2207 | for (i = 0, addr = haddr; i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE) { |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2208 | pte_t entry, *pte; |
| 2209 | /* |
| 2210 | * Note that NUMA hinting access restrictions are not |
| 2211 | * transferred to avoid any possibility of altering |
| 2212 | * permissions across VMAs. |
| 2213 | */ |
Zi Yan | 84c3fc4 | 2017-09-08 16:11:01 -0700 | [diff] [blame] | 2214 | if (freeze || pmd_migration) { |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2215 | swp_entry_t swp_entry; |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 2216 | if (write) |
| 2217 | swp_entry = make_writable_migration_entry( |
| 2218 | page_to_pfn(page + i)); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2219 | else if (anon_exclusive) |
| 2220 | swp_entry = make_readable_exclusive_migration_entry( |
| 2221 | page_to_pfn(page + i)); |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 2222 | else |
| 2223 | swp_entry = make_readable_migration_entry( |
| 2224 | page_to_pfn(page + i)); |
Peter Xu | 2e34687 | 2022-08-11 12:13:29 -0400 | [diff] [blame] | 2225 | if (young) |
| 2226 | swp_entry = make_migration_entry_young(swp_entry); |
| 2227 | if (dirty) |
| 2228 | swp_entry = make_migration_entry_dirty(swp_entry); |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2229 | entry = swp_entry_to_pte(swp_entry); |
Andrea Arcangeli | 804dd15 | 2016-08-25 15:16:57 -0700 | [diff] [blame] | 2230 | if (soft_dirty) |
| 2231 | entry = pte_swp_mksoft_dirty(entry); |
Peter Xu | f45ec5f | 2020-04-06 20:06:01 -0700 | [diff] [blame] | 2232 | if (uffd_wp) |
| 2233 | entry = pte_swp_mkuffd_wp(entry); |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2234 | } else { |
Andrea Arcangeli | 6d2329f | 2016-10-07 17:01:22 -0700 | [diff] [blame] | 2235 | entry = mk_pte(page + i, READ_ONCE(vma->vm_page_prot)); |
David Hildenbrand | 1462c52 | 2023-04-11 16:25:12 +0200 | [diff] [blame] | 2236 | if (write) |
David Hildenbrand | f3ebdf0 | 2023-04-18 16:21:13 +0200 | [diff] [blame] | 2237 | entry = pte_mkwrite(entry); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2238 | if (anon_exclusive) |
| 2239 | SetPageAnonExclusive(page + i); |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2240 | if (!young) |
| 2241 | entry = pte_mkold(entry); |
Peter Xu | e833bc5 | 2022-11-25 13:58:57 -0500 | [diff] [blame] | 2242 | /* NOTE: this may set soft-dirty too on some archs */ |
| 2243 | if (dirty) |
| 2244 | entry = pte_mkdirty(entry); |
Andrea Arcangeli | 804dd15 | 2016-08-25 15:16:57 -0700 | [diff] [blame] | 2245 | if (soft_dirty) |
| 2246 | entry = pte_mksoft_dirty(entry); |
Peter Xu | 292924b | 2020-04-06 20:05:49 -0700 | [diff] [blame] | 2247 | if (uffd_wp) |
| 2248 | entry = pte_mkuffd_wp(entry); |
Hugh Dickins | 96d82de | 2022-11-22 01:51:50 -0800 | [diff] [blame] | 2249 | page_add_anon_rmap(page + i, vma, addr, false); |
Kirill A. Shutemov | ba98828 | 2016-01-15 16:53:56 -0800 | [diff] [blame] | 2250 | } |
Kirill A. Shutemov | 2ac015e | 2016-02-24 18:58:03 +0300 | [diff] [blame] | 2251 | pte = pte_offset_map(&_pmd, addr); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2252 | BUG_ON(!pte_none(*pte)); |
Kirill A. Shutemov | 2ac015e | 2016-02-24 18:58:03 +0300 | [diff] [blame] | 2253 | set_pte_at(mm, addr, pte, entry); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2254 | pte_unmap(pte); |
| 2255 | } |
| 2256 | |
Hugh Dickins | cb67f42 | 2022-11-02 18:51:38 -0700 | [diff] [blame] | 2257 | if (!pmd_migration) |
| 2258 | page_remove_rmap(page, vma, true); |
Hugh Dickins | 96d82de | 2022-11-22 01:51:50 -0800 | [diff] [blame] | 2259 | if (freeze) |
| 2260 | put_page(page); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2261 | |
| 2262 | smp_wmb(); /* make pte visible before pmd */ |
| 2263 | pmd_populate(mm, pmd, pgtable); |
| 2264 | } |
| 2265 | |
| 2266 | void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, |
Matthew Wilcox (Oracle) | af28a98 | 2022-01-21 10:44:52 -0500 | [diff] [blame] | 2267 | unsigned long address, bool freeze, struct folio *folio) |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2268 | { |
| 2269 | spinlock_t *ptl; |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2270 | struct mmu_notifier_range range; |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2271 | |
Alistair Popple | 7d4a8be | 2023-01-10 13:57:22 +1100 | [diff] [blame] | 2272 | mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma->vm_mm, |
Jérôme Glisse | 6f4f13e | 2019-05-13 17:20:49 -0700 | [diff] [blame] | 2273 | address & HPAGE_PMD_MASK, |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2274 | (address & HPAGE_PMD_MASK) + HPAGE_PMD_SIZE); |
| 2275 | mmu_notifier_invalidate_range_start(&range); |
| 2276 | ptl = pmd_lock(vma->vm_mm, pmd); |
Naoya Horiguchi | 33f4751 | 2016-07-14 12:07:32 -0700 | [diff] [blame] | 2277 | |
| 2278 | /* |
Matthew Wilcox (Oracle) | af28a98 | 2022-01-21 10:44:52 -0500 | [diff] [blame] | 2279 | * If caller asks to setup a migration entry, we need a folio to check |
| 2280 | * pmd against. Otherwise we can end up replacing wrong folio. |
Naoya Horiguchi | 33f4751 | 2016-07-14 12:07:32 -0700 | [diff] [blame] | 2281 | */ |
Matthew Wilcox (Oracle) | af28a98 | 2022-01-21 10:44:52 -0500 | [diff] [blame] | 2282 | VM_BUG_ON(freeze && !folio); |
Matthew Wilcox (Oracle) | 83a8441 | 2022-04-06 08:41:39 -0400 | [diff] [blame] | 2283 | VM_WARN_ON_ONCE(folio && !folio_test_locked(folio)); |
Naoya Horiguchi | 33f4751 | 2016-07-14 12:07:32 -0700 | [diff] [blame] | 2284 | |
David Hildenbrand | 7f76091 | 2022-03-24 18:13:56 -0700 | [diff] [blame] | 2285 | if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd) || |
Matthew Wilcox (Oracle) | 83a8441 | 2022-04-06 08:41:39 -0400 | [diff] [blame] | 2286 | is_pmd_migration_entry(*pmd)) { |
Miaohe Lin | cea3332 | 2022-07-04 21:22:00 +0800 | [diff] [blame] | 2287 | /* |
| 2288 | * It's safe to call pmd_page when folio is set because it's |
| 2289 | * guaranteed that pmd is present. |
| 2290 | */ |
Matthew Wilcox (Oracle) | 83a8441 | 2022-04-06 08:41:39 -0400 | [diff] [blame] | 2291 | if (folio && folio != page_folio(pmd_page(*pmd))) |
| 2292 | goto out; |
David Hildenbrand | 7f76091 | 2022-03-24 18:13:56 -0700 | [diff] [blame] | 2293 | __split_huge_pmd_locked(vma, pmd, range.start, freeze); |
Matthew Wilcox (Oracle) | 83a8441 | 2022-04-06 08:41:39 -0400 | [diff] [blame] | 2294 | } |
David Hildenbrand | 7f76091 | 2022-03-24 18:13:56 -0700 | [diff] [blame] | 2295 | |
Kirill A. Shutemov | e90309c | 2016-01-15 16:54:33 -0800 | [diff] [blame] | 2296 | out: |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2297 | spin_unlock(ptl); |
Jérôme Glisse | 4645b9f | 2017-11-15 17:34:11 -0800 | [diff] [blame] | 2298 | /* |
| 2299 | * No need to double call mmu_notifier->invalidate_range() callback. |
| 2300 | * They are 3 cases to consider inside __split_huge_pmd_locked(): |
| 2301 | * 1) pmdp_huge_clear_flush_notify() call invalidate_range() obvious |
| 2302 | * 2) __split_huge_zero_page_pmd() read only zero page and any write |
| 2303 | * fault will trigger a flush_notify before pointing to a new page |
| 2304 | * (it is fine if the secondary mmu keeps pointing to the old zero |
| 2305 | * page in the meantime) |
| 2306 | * 3) Split a huge pmd into pte pointing to the same page. No need |
| 2307 | * to invalidate secondary tlb entry they are all still valid. |
| 2308 | * any further changes to individual pte will notify. So no need |
| 2309 | * to call mmu_notifier->invalidate_range() |
| 2310 | */ |
Jérôme Glisse | ac46d4f | 2018-12-28 00:38:09 -0800 | [diff] [blame] | 2311 | mmu_notifier_invalidate_range_only_end(&range); |
Kirill A. Shutemov | eef1b3b | 2016-01-15 16:53:53 -0800 | [diff] [blame] | 2312 | } |
| 2313 | |
Kirill A. Shutemov | fec89c1 | 2016-03-17 14:20:10 -0700 | [diff] [blame] | 2314 | void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, |
Matthew Wilcox (Oracle) | af28a98 | 2022-01-21 10:44:52 -0500 | [diff] [blame] | 2315 | bool freeze, struct folio *folio) |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2316 | { |
Zach O'Keefe | 5072280 | 2022-07-06 16:59:26 -0700 | [diff] [blame] | 2317 | pmd_t *pmd = mm_find_pmd(vma->vm_mm, address); |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2318 | |
Zach O'Keefe | 5072280 | 2022-07-06 16:59:26 -0700 | [diff] [blame] | 2319 | if (!pmd) |
Hugh Dickins | f72e7dc | 2014-06-23 13:22:05 -0700 | [diff] [blame] | 2320 | return; |
| 2321 | |
Matthew Wilcox (Oracle) | af28a98 | 2022-01-21 10:44:52 -0500 | [diff] [blame] | 2322 | __split_huge_pmd(vma, pmd, address, freeze, folio); |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2323 | } |
| 2324 | |
Miaohe Lin | 71f9e58 | 2021-05-04 18:33:52 -0700 | [diff] [blame] | 2325 | static inline void split_huge_pmd_if_needed(struct vm_area_struct *vma, unsigned long address) |
| 2326 | { |
| 2327 | /* |
| 2328 | * If the new address isn't hpage aligned and it could previously |
| 2329 | * contain an hugepage: check if we need to split an huge pmd. |
| 2330 | */ |
| 2331 | if (!IS_ALIGNED(address, HPAGE_PMD_SIZE) && |
| 2332 | range_in_vma(vma, ALIGN_DOWN(address, HPAGE_PMD_SIZE), |
| 2333 | ALIGN(address, HPAGE_PMD_SIZE))) |
| 2334 | split_huge_pmd_address(vma, address, false, NULL); |
| 2335 | } |
| 2336 | |
Kirill A. Shutemov | e1b9996 | 2015-09-08 14:58:37 -0700 | [diff] [blame] | 2337 | void vma_adjust_trans_huge(struct vm_area_struct *vma, |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2338 | unsigned long start, |
| 2339 | unsigned long end, |
| 2340 | long adjust_next) |
| 2341 | { |
Miaohe Lin | 71f9e58 | 2021-05-04 18:33:52 -0700 | [diff] [blame] | 2342 | /* Check if we need to split start first. */ |
| 2343 | split_huge_pmd_if_needed(vma, start); |
| 2344 | |
| 2345 | /* Check if we need to split end next. */ |
| 2346 | split_huge_pmd_if_needed(vma, end); |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2347 | |
| 2348 | /* |
Matthew Wilcox (Oracle) | 6854050 | 2022-09-06 19:49:00 +0000 | [diff] [blame] | 2349 | * If we're also updating the next vma vm_start, |
Miaohe Lin | 71f9e58 | 2021-05-04 18:33:52 -0700 | [diff] [blame] | 2350 | * check if we need to split it. |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2351 | */ |
| 2352 | if (adjust_next > 0) { |
Matthew Wilcox (Oracle) | 6854050 | 2022-09-06 19:49:00 +0000 | [diff] [blame] | 2353 | struct vm_area_struct *next = find_vma(vma->vm_mm, vma->vm_end); |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2354 | unsigned long nstart = next->vm_start; |
Wei Yang | f9d86a6 | 2020-10-13 16:53:57 -0700 | [diff] [blame] | 2355 | nstart += adjust_next; |
Miaohe Lin | 71f9e58 | 2021-05-04 18:33:52 -0700 | [diff] [blame] | 2356 | split_huge_pmd_if_needed(next, nstart); |
Andrea Arcangeli | 94fcc58 | 2011-01-13 15:47:08 -0800 | [diff] [blame] | 2357 | } |
| 2358 | } |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2359 | |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2360 | static void unmap_folio(struct folio *folio) |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2361 | { |
Alistair Popple | a98a2f0 | 2021-06-30 18:54:16 -0700 | [diff] [blame] | 2362 | enum ttu_flags ttu_flags = TTU_RMAP_LOCKED | TTU_SPLIT_HUGE_PMD | |
| 2363 | TTU_SYNC; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2364 | |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2365 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2366 | |
Alistair Popple | a98a2f0 | 2021-06-30 18:54:16 -0700 | [diff] [blame] | 2367 | /* |
| 2368 | * Anon pages need migration entries to preserve them, but file |
| 2369 | * pages can simply be left unmapped, then faulted back on demand. |
| 2370 | * If that is ever changed (perhaps for mlock), update remap_page(). |
| 2371 | */ |
Matthew Wilcox (Oracle) | 4b8554c | 2022-01-28 14:29:43 -0500 | [diff] [blame] | 2372 | if (folio_test_anon(folio)) |
| 2373 | try_to_migrate(folio, ttu_flags); |
Alistair Popple | a98a2f0 | 2021-06-30 18:54:16 -0700 | [diff] [blame] | 2374 | else |
Matthew Wilcox (Oracle) | 869f7ee | 2022-02-15 09:28:49 -0500 | [diff] [blame] | 2375 | try_to_unmap(folio, ttu_flags | TTU_IGNORE_MLOCK); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2376 | } |
| 2377 | |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2378 | static void remap_page(struct folio *folio, unsigned long nr) |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2379 | { |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2380 | int i = 0; |
Hugh Dickins | ab02c25 | 2021-06-30 18:52:04 -0700 | [diff] [blame] | 2381 | |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2382 | /* If unmap_folio() uses try_to_migrate() on file, remove this check */ |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2383 | if (!folio_test_anon(folio)) |
Hugh Dickins | ab02c25 | 2021-06-30 18:52:04 -0700 | [diff] [blame] | 2384 | return; |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2385 | for (;;) { |
| 2386 | remove_migration_ptes(folio, folio, true); |
| 2387 | i += folio_nr_pages(folio); |
| 2388 | if (i >= nr) |
| 2389 | break; |
| 2390 | folio = folio_next(folio); |
Kirill A. Shutemov | ace71a1 | 2017-02-24 14:57:45 -0800 | [diff] [blame] | 2391 | } |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2392 | } |
| 2393 | |
Alex Shi | 9486663 | 2020-12-15 12:33:24 -0800 | [diff] [blame] | 2394 | static void lru_add_page_tail(struct page *head, struct page *tail, |
Alex Shi | 88dcb9a | 2020-12-15 12:33:20 -0800 | [diff] [blame] | 2395 | struct lruvec *lruvec, struct list_head *list) |
| 2396 | { |
Alex Shi | 9486663 | 2020-12-15 12:33:24 -0800 | [diff] [blame] | 2397 | VM_BUG_ON_PAGE(!PageHead(head), head); |
| 2398 | VM_BUG_ON_PAGE(PageCompound(tail), head); |
| 2399 | VM_BUG_ON_PAGE(PageLRU(tail), head); |
Alex Shi | 6168d0d | 2020-12-15 12:34:29 -0800 | [diff] [blame] | 2400 | lockdep_assert_held(&lruvec->lru_lock); |
Alex Shi | 88dcb9a | 2020-12-15 12:33:20 -0800 | [diff] [blame] | 2401 | |
Alex Shi | 6dbb574 | 2020-12-15 12:33:29 -0800 | [diff] [blame] | 2402 | if (list) { |
Alex Shi | 88dcb9a | 2020-12-15 12:33:20 -0800 | [diff] [blame] | 2403 | /* page reclaim is reclaiming a huge page */ |
Alex Shi | 6dbb574 | 2020-12-15 12:33:29 -0800 | [diff] [blame] | 2404 | VM_WARN_ON(PageLRU(head)); |
Alex Shi | 9486663 | 2020-12-15 12:33:24 -0800 | [diff] [blame] | 2405 | get_page(tail); |
| 2406 | list_add_tail(&tail->lru, list); |
Alex Shi | 88dcb9a | 2020-12-15 12:33:20 -0800 | [diff] [blame] | 2407 | } else { |
Alex Shi | 6dbb574 | 2020-12-15 12:33:29 -0800 | [diff] [blame] | 2408 | /* head is still on lru (and we have it frozen) */ |
| 2409 | VM_WARN_ON(!PageLRU(head)); |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 2410 | if (PageUnevictable(tail)) |
| 2411 | tail->mlock_count = 0; |
| 2412 | else |
| 2413 | list_add_tail(&tail->lru, &head->lru); |
Alex Shi | 6dbb574 | 2020-12-15 12:33:29 -0800 | [diff] [blame] | 2414 | SetPageLRU(tail); |
Alex Shi | 88dcb9a | 2020-12-15 12:33:20 -0800 | [diff] [blame] | 2415 | } |
| 2416 | } |
| 2417 | |
Kirill A. Shutemov | 8df651c | 2016-03-15 14:57:30 -0700 | [diff] [blame] | 2418 | static void __split_huge_page_tail(struct page *head, int tail, |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2419 | struct lruvec *lruvec, struct list_head *list) |
| 2420 | { |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2421 | struct page *page_tail = head + tail; |
| 2422 | |
Kirill A. Shutemov | 8df651c | 2016-03-15 14:57:30 -0700 | [diff] [blame] | 2423 | VM_BUG_ON_PAGE(atomic_read(&page_tail->_mapcount) != -1, page_tail); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2424 | |
| 2425 | /* |
Konstantin Khlebnikov | 605ca5e | 2018-04-05 16:23:28 -0700 | [diff] [blame] | 2426 | * Clone page flags before unfreezing refcount. |
| 2427 | * |
| 2428 | * After successful get_page_unless_zero() might follow flags change, |
Haitao Shi | 8958b24 | 2020-12-15 20:47:26 -0800 | [diff] [blame] | 2429 | * for example lock_page() which set PG_waiters. |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2430 | * |
| 2431 | * Note that for mapped sub-pages of an anonymous THP, |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2432 | * PG_anon_exclusive has been cleared in unmap_folio() and is stored in |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 2433 | * the migration entry instead from where remap_page() will restore it. |
| 2434 | * We can still have PG_anon_exclusive set on effectively unmapped and |
| 2435 | * unreferenced sub-pages of an anonymous THP: we can simply drop |
| 2436 | * PG_anon_exclusive (-> PG_mappedtodisk) for these here. |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2437 | */ |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2438 | page_tail->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; |
| 2439 | page_tail->flags |= (head->flags & |
| 2440 | ((1L << PG_referenced) | |
| 2441 | (1L << PG_swapbacked) | |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 2442 | (1L << PG_swapcache) | |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2443 | (1L << PG_mlocked) | |
| 2444 | (1L << PG_uptodate) | |
| 2445 | (1L << PG_active) | |
Johannes Weiner | 1899ad1 | 2018-10-26 15:06:04 -0700 | [diff] [blame] | 2446 | (1L << PG_workingset) | |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2447 | (1L << PG_locked) | |
Minchan Kim | b8d3c4c | 2016-01-15 16:55:42 -0800 | [diff] [blame] | 2448 | (1L << PG_unevictable) | |
Catalin Marinas | b0284cd | 2022-11-03 18:10:34 -0700 | [diff] [blame] | 2449 | #ifdef CONFIG_ARCH_USES_PG_ARCH_X |
Catalin Marinas | 72e6afa | 2020-07-02 10:19:30 +0100 | [diff] [blame] | 2450 | (1L << PG_arch_2) | |
Peter Collingbourne | ef6458b | 2022-11-03 18:10:37 -0700 | [diff] [blame] | 2451 | (1L << PG_arch_3) | |
Catalin Marinas | 72e6afa | 2020-07-02 10:19:30 +0100 | [diff] [blame] | 2452 | #endif |
Yu Zhao | ec1c86b | 2022-09-18 02:00:02 -0600 | [diff] [blame] | 2453 | (1L << PG_dirty) | |
| 2454 | LRU_GEN_MASK | LRU_REFS_MASK)); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2455 | |
Hugh Dickins | cb67f42 | 2022-11-02 18:51:38 -0700 | [diff] [blame] | 2456 | /* ->mapping in first and second tail page is replaced by other uses */ |
Hugh Dickins | 173d9d9 | 2018-11-30 14:10:16 -0800 | [diff] [blame] | 2457 | VM_BUG_ON_PAGE(tail > 2 && page_tail->mapping != TAIL_MAPPING, |
| 2458 | page_tail); |
| 2459 | page_tail->mapping = head->mapping; |
| 2460 | page_tail->index = head->index + tail; |
Mel Gorman | 71e2d66 | 2022-10-19 14:41:56 +0100 | [diff] [blame] | 2461 | |
| 2462 | /* |
| 2463 | * page->private should not be set in tail pages with the exception |
| 2464 | * of swap cache pages that store the swp_entry_t in tail pages. |
| 2465 | * Fix up and warn once if private is unexpectedly set. |
Hugh Dickins | cb67f42 | 2022-11-02 18:51:38 -0700 | [diff] [blame] | 2466 | * |
Matthew Wilcox (Oracle) | 94688e8 | 2023-01-11 14:28:47 +0000 | [diff] [blame] | 2467 | * What of 32-bit systems, on which folio->_pincount overlays |
Hugh Dickins | cb67f42 | 2022-11-02 18:51:38 -0700 | [diff] [blame] | 2468 | * head[1].private? No problem: THP_SWAP is not enabled on 32-bit, and |
Matthew Wilcox (Oracle) | 94688e8 | 2023-01-11 14:28:47 +0000 | [diff] [blame] | 2469 | * pincount must be 0 for folio_ref_freeze() to have succeeded. |
Mel Gorman | 71e2d66 | 2022-10-19 14:41:56 +0100 | [diff] [blame] | 2470 | */ |
| 2471 | if (!folio_test_swapcache(page_folio(head))) { |
Hugh Dickins | 5aae926 | 2022-10-22 00:51:06 -0700 | [diff] [blame] | 2472 | VM_WARN_ON_ONCE_PAGE(page_tail->private != 0, page_tail); |
Mel Gorman | 71e2d66 | 2022-10-19 14:41:56 +0100 | [diff] [blame] | 2473 | page_tail->private = 0; |
| 2474 | } |
Hugh Dickins | 173d9d9 | 2018-11-30 14:10:16 -0800 | [diff] [blame] | 2475 | |
Konstantin Khlebnikov | 605ca5e | 2018-04-05 16:23:28 -0700 | [diff] [blame] | 2476 | /* Page flags must be visible before we make the page non-compound. */ |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2477 | smp_wmb(); |
| 2478 | |
Konstantin Khlebnikov | 605ca5e | 2018-04-05 16:23:28 -0700 | [diff] [blame] | 2479 | /* |
| 2480 | * Clear PageTail before unfreezing page refcount. |
| 2481 | * |
| 2482 | * After successful get_page_unless_zero() might follow put_page() |
| 2483 | * which needs correct compound_head(). |
| 2484 | */ |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2485 | clear_compound_head(page_tail); |
| 2486 | |
Konstantin Khlebnikov | 605ca5e | 2018-04-05 16:23:28 -0700 | [diff] [blame] | 2487 | /* Finally unfreeze refcount. Additional reference from page cache. */ |
| 2488 | page_ref_unfreeze(page_tail, 1 + (!PageAnon(head) || |
| 2489 | PageSwapCache(head))); |
| 2490 | |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2491 | if (page_is_young(head)) |
| 2492 | set_page_young(page_tail); |
| 2493 | if (page_is_idle(head)) |
| 2494 | set_page_idle(page_tail); |
| 2495 | |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2496 | page_cpupid_xchg_last(page_tail, page_cpupid_last(head)); |
Michal Hocko | 94723aa | 2018-04-10 16:30:07 -0700 | [diff] [blame] | 2497 | |
| 2498 | /* |
| 2499 | * always add to the tail because some iterators expect new |
| 2500 | * pages to show after the currently processed elements - e.g. |
| 2501 | * migrate_pages |
| 2502 | */ |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2503 | lru_add_page_tail(head, page_tail, lruvec, list); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2504 | } |
| 2505 | |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2506 | static void __split_huge_page(struct page *page, struct list_head *list, |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2507 | pgoff_t end) |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2508 | { |
Matthew Wilcox (Oracle) | e809c3f | 2021-06-28 21:59:47 -0400 | [diff] [blame] | 2509 | struct folio *folio = page_folio(page); |
| 2510 | struct page *head = &folio->page; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2511 | struct lruvec *lruvec; |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2512 | struct address_space *swap_cache = NULL; |
| 2513 | unsigned long offset = 0; |
Kirill A. Shutemov | 8cce547 | 2020-10-15 20:05:36 -0700 | [diff] [blame] | 2514 | unsigned int nr = thp_nr_pages(head); |
Kirill A. Shutemov | 8df651c | 2016-03-15 14:57:30 -0700 | [diff] [blame] | 2515 | int i; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2516 | |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2517 | /* complete memcg works before add pages to LRU */ |
Zhou Guanghui | be6c898 | 2021-03-12 21:08:30 -0800 | [diff] [blame] | 2518 | split_page_memcg(head, nr); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2519 | |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2520 | if (PageAnon(head) && PageSwapCache(head)) { |
| 2521 | swp_entry_t entry = { .val = page_private(head) }; |
| 2522 | |
| 2523 | offset = swp_offset(entry); |
| 2524 | swap_cache = swap_address_space(entry); |
| 2525 | xa_lock(&swap_cache->i_pages); |
| 2526 | } |
| 2527 | |
Ingo Molnar | f0953a1 | 2021-05-06 18:06:47 -0700 | [diff] [blame] | 2528 | /* lock lru list/PageCompound, ref frozen by page_ref_freeze */ |
Matthew Wilcox (Oracle) | e809c3f | 2021-06-28 21:59:47 -0400 | [diff] [blame] | 2529 | lruvec = folio_lruvec_lock(folio); |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2530 | |
Yang Shi | eac96c3 | 2021-10-28 14:36:11 -0700 | [diff] [blame] | 2531 | ClearPageHasHWPoisoned(head); |
| 2532 | |
Kirill A. Shutemov | 8cce547 | 2020-10-15 20:05:36 -0700 | [diff] [blame] | 2533 | for (i = nr - 1; i >= 1; i--) { |
Kirill A. Shutemov | 8df651c | 2016-03-15 14:57:30 -0700 | [diff] [blame] | 2534 | __split_huge_page_tail(head, i, lruvec, list); |
Hugh Dickins | d144bf6 | 2021-09-02 14:54:21 -0700 | [diff] [blame] | 2535 | /* Some pages can be beyond EOF: drop them from page cache */ |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2536 | if (head[i].index >= end) { |
Matthew Wilcox (Oracle) | fb5c202 | 2022-06-28 20:15:29 -0400 | [diff] [blame] | 2537 | struct folio *tail = page_folio(head + i); |
| 2538 | |
Hugh Dickins | d144bf6 | 2021-09-02 14:54:21 -0700 | [diff] [blame] | 2539 | if (shmem_mapping(head->mapping)) |
Kirill A. Shutemov | 800d8c6 | 2016-07-26 15:26:18 -0700 | [diff] [blame] | 2540 | shmem_uncharge(head->mapping->host, 1); |
Matthew Wilcox (Oracle) | fb5c202 | 2022-06-28 20:15:29 -0400 | [diff] [blame] | 2541 | else if (folio_test_clear_dirty(tail)) |
| 2542 | folio_account_cleaned(tail, |
| 2543 | inode_to_wb(folio->mapping->host)); |
| 2544 | __filemap_remove_folio(tail, NULL); |
| 2545 | folio_put(tail); |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2546 | } else if (!PageAnon(page)) { |
| 2547 | __xa_store(&head->mapping->i_pages, head[i].index, |
| 2548 | head + i, 0); |
| 2549 | } else if (swap_cache) { |
| 2550 | __xa_store(&swap_cache->i_pages, offset + i, |
| 2551 | head + i, 0); |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2552 | } |
| 2553 | } |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2554 | |
| 2555 | ClearPageCompound(head); |
Alex Shi | 6168d0d | 2020-12-15 12:34:29 -0800 | [diff] [blame] | 2556 | unlock_page_lruvec(lruvec); |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2557 | /* Caller disabled irqs, so they are still disabled here */ |
Vlastimil Babka | f7da677 | 2019-08-24 17:54:59 -0700 | [diff] [blame] | 2558 | |
Kirill A. Shutemov | 8cce547 | 2020-10-15 20:05:36 -0700 | [diff] [blame] | 2559 | split_page_owner(head, nr); |
Vlastimil Babka | f7da677 | 2019-08-24 17:54:59 -0700 | [diff] [blame] | 2560 | |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2561 | /* See comment in __split_huge_page_tail() */ |
| 2562 | if (PageAnon(head)) { |
Matthew Wilcox | aa5dc07 | 2017-12-04 10:16:10 -0500 | [diff] [blame] | 2563 | /* Additional pin to swap cache */ |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2564 | if (PageSwapCache(head)) { |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 2565 | page_ref_add(head, 2); |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2566 | xa_unlock(&swap_cache->i_pages); |
| 2567 | } else { |
Huang Ying | 38d8b4e | 2017-07-06 15:37:18 -0700 | [diff] [blame] | 2568 | page_ref_inc(head); |
Matthew Wilcox (Oracle) | 4101196 | 2019-09-23 15:34:52 -0700 | [diff] [blame] | 2569 | } |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2570 | } else { |
Matthew Wilcox | aa5dc07 | 2017-12-04 10:16:10 -0500 | [diff] [blame] | 2571 | /* Additional pin to page cache */ |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2572 | page_ref_add(head, 2); |
Matthew Wilcox | b93b016 | 2018-04-10 16:36:56 -0700 | [diff] [blame] | 2573 | xa_unlock(&head->mapping->i_pages); |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2574 | } |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2575 | local_irq_enable(); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2576 | |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2577 | remap_page(folio, nr); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2578 | |
Huang Ying | c4f9c70 | 2020-10-15 20:06:07 -0700 | [diff] [blame] | 2579 | if (PageSwapCache(head)) { |
| 2580 | swp_entry_t entry = { .val = page_private(head) }; |
| 2581 | |
| 2582 | split_swap_cluster(entry); |
| 2583 | } |
| 2584 | |
Kirill A. Shutemov | 8cce547 | 2020-10-15 20:05:36 -0700 | [diff] [blame] | 2585 | for (i = 0; i < nr; i++) { |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2586 | struct page *subpage = head + i; |
| 2587 | if (subpage == page) |
| 2588 | continue; |
| 2589 | unlock_page(subpage); |
| 2590 | |
| 2591 | /* |
| 2592 | * Subpages may be freed if there wasn't any mapping |
| 2593 | * like if add_to_swap() is running on a lru page that |
| 2594 | * had its mapping zapped. And freeing these pages |
| 2595 | * requires taking the lru_lock so we do the put_page |
| 2596 | * of the tail pages after the split is complete. |
| 2597 | */ |
Miaohe Lin | 0b17546 | 2022-07-04 21:21:56 +0800 | [diff] [blame] | 2598 | free_page_and_swap_cache(subpage); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2599 | } |
| 2600 | } |
| 2601 | |
Huang Ying | b8f593c | 2017-07-06 15:37:28 -0700 | [diff] [blame] | 2602 | /* Racy check whether the huge page can be split */ |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 2603 | bool can_split_folio(struct folio *folio, int *pextra_pins) |
Huang Ying | b8f593c | 2017-07-06 15:37:28 -0700 | [diff] [blame] | 2604 | { |
| 2605 | int extra_pins; |
| 2606 | |
Matthew Wilcox | aa5dc07 | 2017-12-04 10:16:10 -0500 | [diff] [blame] | 2607 | /* Additional pins from page cache */ |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 2608 | if (folio_test_anon(folio)) |
| 2609 | extra_pins = folio_test_swapcache(folio) ? |
| 2610 | folio_nr_pages(folio) : 0; |
Huang Ying | b8f593c | 2017-07-06 15:37:28 -0700 | [diff] [blame] | 2611 | else |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 2612 | extra_pins = folio_nr_pages(folio); |
Huang Ying | b8f593c | 2017-07-06 15:37:28 -0700 | [diff] [blame] | 2613 | if (pextra_pins) |
| 2614 | *pextra_pins = extra_pins; |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 2615 | return folio_mapcount(folio) == folio_ref_count(folio) - extra_pins - 1; |
Huang Ying | b8f593c | 2017-07-06 15:37:28 -0700 | [diff] [blame] | 2616 | } |
| 2617 | |
Andrea Arcangeli | 6d0a07e | 2016-05-12 15:42:25 -0700 | [diff] [blame] | 2618 | /* |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2619 | * This function splits huge page into normal pages. @page can point to any |
| 2620 | * subpage of huge page to split. Split doesn't change the position of @page. |
| 2621 | * |
| 2622 | * Only caller must hold pin on the @page, otherwise split fails with -EBUSY. |
| 2623 | * The huge page must be locked. |
| 2624 | * |
| 2625 | * If @list is null, tail pages will be added to LRU list, otherwise, to @list. |
| 2626 | * |
| 2627 | * Both head page and tail pages will inherit mapping, flags, and so on from |
| 2628 | * the hugepage. |
| 2629 | * |
| 2630 | * GUP pin and PG_locked transferred to @page. Rest subpages can be freed if |
| 2631 | * they are not mapped. |
| 2632 | * |
| 2633 | * Returns 0 if the hugepage is split successfully. |
| 2634 | * Returns -EBUSY if the page is pinned or if anon_vma disappeared from under |
| 2635 | * us. |
| 2636 | */ |
| 2637 | int split_huge_page_to_list(struct page *page, struct list_head *list) |
| 2638 | { |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2639 | struct folio *folio = page_folio(page); |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 2640 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2641 | XA_STATE(xas, &folio->mapping->i_pages, folio->index); |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2642 | struct anon_vma *anon_vma = NULL; |
| 2643 | struct address_space *mapping = NULL; |
Yang Shi | 504e070 | 2021-06-15 18:24:07 -0700 | [diff] [blame] | 2644 | int extra_pins, ret; |
Hugh Dickins | 006d3ff | 2018-11-30 14:10:21 -0800 | [diff] [blame] | 2645 | pgoff_t end; |
Xu Yu | 478d134 | 2022-04-28 23:14:43 -0700 | [diff] [blame] | 2646 | bool is_hzp; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2647 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2648 | VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); |
| 2649 | VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2650 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2651 | is_hzp = is_huge_zero_page(&folio->page); |
Naoya Horiguchi | 4737edb | 2023-04-06 17:20:04 +0900 | [diff] [blame] | 2652 | if (is_hzp) { |
| 2653 | pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); |
Xu Yu | 478d134 | 2022-04-28 23:14:43 -0700 | [diff] [blame] | 2654 | return -EBUSY; |
Naoya Horiguchi | 4737edb | 2023-04-06 17:20:04 +0900 | [diff] [blame] | 2655 | } |
Xu Yu | 478d134 | 2022-04-28 23:14:43 -0700 | [diff] [blame] | 2656 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2657 | if (folio_test_writeback(folio)) |
Huang Ying | 5980768 | 2017-09-06 16:22:34 -0700 | [diff] [blame] | 2658 | return -EBUSY; |
| 2659 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2660 | if (folio_test_anon(folio)) { |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2661 | /* |
Michel Lespinasse | c1e8d7c | 2020-06-08 21:33:54 -0700 | [diff] [blame] | 2662 | * The caller does not necessarily hold an mmap_lock that would |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2663 | * prevent the anon_vma disappearing so we first we take a |
| 2664 | * reference to it and then lock the anon_vma for write. This |
Matthew Wilcox (Oracle) | 2f031c6 | 2022-01-29 16:06:53 -0500 | [diff] [blame] | 2665 | * is similar to folio_lock_anon_vma_read except the write lock |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2666 | * is taken to serialise against parallel split or collapse |
| 2667 | * operations. |
| 2668 | */ |
Matthew Wilcox (Oracle) | 29eea9b | 2022-09-02 20:46:50 +0100 | [diff] [blame] | 2669 | anon_vma = folio_get_anon_vma(folio); |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2670 | if (!anon_vma) { |
| 2671 | ret = -EBUSY; |
| 2672 | goto out; |
| 2673 | } |
Hugh Dickins | 006d3ff | 2018-11-30 14:10:21 -0800 | [diff] [blame] | 2674 | end = -1; |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2675 | mapping = NULL; |
| 2676 | anon_vma_lock_write(anon_vma); |
| 2677 | } else { |
Yin Fengwei | 6a3edd29 | 2022-08-10 14:49:07 +0800 | [diff] [blame] | 2678 | gfp_t gfp; |
| 2679 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2680 | mapping = folio->mapping; |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2681 | |
| 2682 | /* Truncated ? */ |
| 2683 | if (!mapping) { |
| 2684 | ret = -EBUSY; |
| 2685 | goto out; |
| 2686 | } |
| 2687 | |
Yin Fengwei | 6a3edd29 | 2022-08-10 14:49:07 +0800 | [diff] [blame] | 2688 | gfp = current_gfp_context(mapping_gfp_mask(mapping) & |
| 2689 | GFP_RECLAIM_MASK); |
| 2690 | |
| 2691 | if (folio_test_private(folio) && |
| 2692 | !filemap_release_folio(folio, gfp)) { |
| 2693 | ret = -EBUSY; |
| 2694 | goto out; |
| 2695 | } |
| 2696 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2697 | xas_split_alloc(&xas, folio, folio_order(folio), gfp); |
Matthew Wilcox (Oracle) | 6b24ca4 | 2020-06-27 22:19:08 -0400 | [diff] [blame] | 2698 | if (xas_error(&xas)) { |
| 2699 | ret = xas_error(&xas); |
| 2700 | goto out; |
| 2701 | } |
| 2702 | |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2703 | anon_vma = NULL; |
| 2704 | i_mmap_lock_read(mapping); |
Hugh Dickins | 006d3ff | 2018-11-30 14:10:21 -0800 | [diff] [blame] | 2705 | |
| 2706 | /* |
| 2707 | *__split_huge_page() may need to trim off pages beyond EOF: |
| 2708 | * but on 32-bit, i_size_read() takes an irq-unsafe seqlock, |
| 2709 | * which cannot be nested inside the page tree lock. So note |
| 2710 | * end now: i_size itself may be changed at any moment, but |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2711 | * folio lock is good enough to serialize the trimming. |
Hugh Dickins | 006d3ff | 2018-11-30 14:10:21 -0800 | [diff] [blame] | 2712 | */ |
| 2713 | end = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE); |
Hugh Dickins | d144bf6 | 2021-09-02 14:54:21 -0700 | [diff] [blame] | 2714 | if (shmem_mapping(mapping)) |
| 2715 | end = shmem_fallocend(mapping->host, end); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2716 | } |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2717 | |
| 2718 | /* |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2719 | * Racy check if we can split the page, before unmap_folio() will |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2720 | * split PMDs |
| 2721 | */ |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 2722 | if (!can_split_folio(folio, &extra_pins)) { |
Baolin Wang | fd4a7ac | 2022-10-24 16:34:22 +0800 | [diff] [blame] | 2723 | ret = -EAGAIN; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2724 | goto out_unlock; |
| 2725 | } |
| 2726 | |
Matthew Wilcox (Oracle) | 684555a | 2022-09-02 20:46:49 +0100 | [diff] [blame] | 2727 | unmap_folio(folio); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2728 | |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2729 | /* block interrupt reentry in xa_lock and spinlock */ |
| 2730 | local_irq_disable(); |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2731 | if (mapping) { |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2732 | /* |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2733 | * Check if the folio is present in page cache. |
| 2734 | * We assume all tail are present too, if folio is there. |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2735 | */ |
Matthew Wilcox (Oracle) | 6b24ca4 | 2020-06-27 22:19:08 -0400 | [diff] [blame] | 2736 | xas_lock(&xas); |
| 2737 | xas_reset(&xas); |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2738 | if (xas_load(&xas) != folio) |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2739 | goto fail; |
| 2740 | } |
| 2741 | |
Joonsoo Kim | 0139aa7 | 2016-05-19 17:10:49 -0700 | [diff] [blame] | 2742 | /* Prevent deferred_split_scan() touching ->_refcount */ |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2743 | spin_lock(&ds_queue->split_queue_lock); |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2744 | if (folio_ref_freeze(folio, 1 + extra_pins)) { |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2745 | if (!list_empty(&folio->_deferred_list)) { |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2746 | ds_queue->split_queue_len--; |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2747 | list_del(&folio->_deferred_list); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2748 | } |
Wei Yang | afb9717 | 2020-01-30 22:14:35 -0800 | [diff] [blame] | 2749 | spin_unlock(&ds_queue->split_queue_lock); |
Kirill A. Shutemov | 06d3eff | 2019-10-18 20:20:30 -0700 | [diff] [blame] | 2750 | if (mapping) { |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2751 | int nr = folio_nr_pages(folio); |
Muchun Song | bf9ecea | 2021-02-24 12:03:27 -0800 | [diff] [blame] | 2752 | |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2753 | xas_split(&xas, folio, folio_order(folio)); |
| 2754 | if (folio_test_swapbacked(folio)) { |
| 2755 | __lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, |
Muchun Song | 57b2847 | 2021-02-24 12:03:31 -0800 | [diff] [blame] | 2756 | -nr); |
Marek Szyprowski | 1ca7554 | 2021-10-18 15:16:19 -0700 | [diff] [blame] | 2757 | } else { |
Matthew Wilcox (Oracle) | 3e9a13d | 2022-09-02 20:46:48 +0100 | [diff] [blame] | 2758 | __lruvec_stat_mod_folio(folio, NR_FILE_THPS, |
Muchun Song | bf9ecea | 2021-02-24 12:03:27 -0800 | [diff] [blame] | 2759 | -nr); |
Marek Szyprowski | 1ca7554 | 2021-10-18 15:16:19 -0700 | [diff] [blame] | 2760 | filemap_nr_thps_dec(mapping); |
| 2761 | } |
Kirill A. Shutemov | 06d3eff | 2019-10-18 20:20:30 -0700 | [diff] [blame] | 2762 | } |
| 2763 | |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2764 | __split_huge_page(page, list, end); |
Huang Ying | c4f9c70 | 2020-10-15 20:06:07 -0700 | [diff] [blame] | 2765 | ret = 0; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2766 | } else { |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2767 | spin_unlock(&ds_queue->split_queue_lock); |
Yang Shi | 504e070 | 2021-06-15 18:24:07 -0700 | [diff] [blame] | 2768 | fail: |
| 2769 | if (mapping) |
Matthew Wilcox (Oracle) | 6b24ca4 | 2020-06-27 22:19:08 -0400 | [diff] [blame] | 2770 | xas_unlock(&xas); |
Alex Shi | b676983 | 2020-12-15 12:33:33 -0800 | [diff] [blame] | 2771 | local_irq_enable(); |
Matthew Wilcox (Oracle) | 4eecb8b | 2022-01-28 23:32:59 -0500 | [diff] [blame] | 2772 | remap_page(folio, folio_nr_pages(folio)); |
Baolin Wang | fd4a7ac | 2022-10-24 16:34:22 +0800 | [diff] [blame] | 2773 | ret = -EAGAIN; |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2774 | } |
| 2775 | |
| 2776 | out_unlock: |
Kirill A. Shutemov | baa355f | 2016-07-26 15:25:51 -0700 | [diff] [blame] | 2777 | if (anon_vma) { |
| 2778 | anon_vma_unlock_write(anon_vma); |
| 2779 | put_anon_vma(anon_vma); |
| 2780 | } |
| 2781 | if (mapping) |
| 2782 | i_mmap_unlock_read(mapping); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2783 | out: |
Matthew Wilcox (Oracle) | 69a37a8 | 2022-06-08 15:18:34 -0400 | [diff] [blame] | 2784 | xas_destroy(&xas); |
Kirill A. Shutemov | e9b61f1 | 2016-01-15 16:54:10 -0800 | [diff] [blame] | 2785 | count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); |
| 2786 | return ret; |
| 2787 | } |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2788 | |
| 2789 | void free_transhuge_page(struct page *page) |
| 2790 | { |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2791 | struct folio *folio = (struct folio *)page; |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 2792 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2793 | unsigned long flags; |
| 2794 | |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2795 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2796 | if (!list_empty(&folio->_deferred_list)) { |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2797 | ds_queue->split_queue_len--; |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2798 | list_del(&folio->_deferred_list); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2799 | } |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2800 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2801 | free_compound_page(page); |
| 2802 | } |
| 2803 | |
Matthew Wilcox (Oracle) | f158ed6 | 2023-01-11 14:29:13 +0000 | [diff] [blame] | 2804 | void deferred_split_folio(struct folio *folio) |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2805 | { |
Matthew Wilcox (Oracle) | f8baa6b | 2023-01-11 14:29:12 +0000 | [diff] [blame] | 2806 | struct deferred_split *ds_queue = get_deferred_split_queue(folio); |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2807 | #ifdef CONFIG_MEMCG |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2808 | struct mem_cgroup *memcg = folio_memcg(folio); |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2809 | #endif |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2810 | unsigned long flags; |
| 2811 | |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2812 | VM_BUG_ON_FOLIO(folio_order(folio) < 2, folio); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2813 | |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2814 | /* |
| 2815 | * The try_to_unmap() in page reclaim path might reach here too, |
| 2816 | * this may cause a race condition to corrupt deferred split queue. |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2817 | * And, if page reclaim is already handling the same folio, it is |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2818 | * unnecessary to handle it again in shrinker. |
| 2819 | * |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2820 | * Check the swapcache flag to determine if the folio is being |
| 2821 | * handled by page reclaim since THP swap would add the folio into |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2822 | * swap cache before calling try_to_unmap(). |
| 2823 | */ |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2824 | if (folio_test_swapcache(folio)) |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2825 | return; |
| 2826 | |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2827 | if (!list_empty(&folio->_deferred_list)) |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2828 | return; |
| 2829 | |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2830 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2831 | if (list_empty(&folio->_deferred_list)) { |
Kirill A. Shutemov | f9719a0 | 2016-03-17 14:18:45 -0700 | [diff] [blame] | 2832 | count_vm_event(THP_DEFERRED_SPLIT_PAGE); |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2833 | list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2834 | ds_queue->split_queue_len++; |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2835 | #ifdef CONFIG_MEMCG |
| 2836 | if (memcg) |
Matthew Wilcox (Oracle) | 8991de9 | 2023-01-11 14:29:11 +0000 | [diff] [blame] | 2837 | set_shrinker_bit(memcg, folio_nid(folio), |
Yang Shi | 2bfd363 | 2021-05-04 18:36:11 -0700 | [diff] [blame] | 2838 | deferred_split_shrinker.id); |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2839 | #endif |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2840 | } |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2841 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2842 | } |
| 2843 | |
| 2844 | static unsigned long deferred_split_count(struct shrinker *shrink, |
| 2845 | struct shrink_control *sc) |
| 2846 | { |
Kirill A. Shutemov | a3d0a918 | 2016-02-02 16:57:08 -0800 | [diff] [blame] | 2847 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2848 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2849 | |
| 2850 | #ifdef CONFIG_MEMCG |
| 2851 | if (sc->memcg) |
| 2852 | ds_queue = &sc->memcg->deferred_split_queue; |
| 2853 | #endif |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2854 | return READ_ONCE(ds_queue->split_queue_len); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2855 | } |
| 2856 | |
| 2857 | static unsigned long deferred_split_scan(struct shrinker *shrink, |
| 2858 | struct shrink_control *sc) |
| 2859 | { |
Kirill A. Shutemov | a3d0a918 | 2016-02-02 16:57:08 -0800 | [diff] [blame] | 2860 | struct pglist_data *pgdata = NODE_DATA(sc->nid); |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2861 | struct deferred_split *ds_queue = &pgdata->deferred_split_queue; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2862 | unsigned long flags; |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2863 | LIST_HEAD(list); |
| 2864 | struct folio *folio, *next; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2865 | int split = 0; |
| 2866 | |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2867 | #ifdef CONFIG_MEMCG |
| 2868 | if (sc->memcg) |
| 2869 | ds_queue = &sc->memcg->deferred_split_queue; |
| 2870 | #endif |
| 2871 | |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2872 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2873 | /* Take pin on all head pages to avoid freeing them under us */ |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2874 | list_for_each_entry_safe(folio, next, &ds_queue->split_queue, |
| 2875 | _deferred_list) { |
| 2876 | if (folio_try_get(folio)) { |
| 2877 | list_move(&folio->_deferred_list, &list); |
Kirill A. Shutemov | e3ae195 | 2016-02-02 16:57:15 -0800 | [diff] [blame] | 2878 | } else { |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2879 | /* We lost race with folio_put() */ |
| 2880 | list_del_init(&folio->_deferred_list); |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2881 | ds_queue->split_queue_len--; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2882 | } |
Kirill A. Shutemov | e3ae195 | 2016-02-02 16:57:15 -0800 | [diff] [blame] | 2883 | if (!--sc->nr_to_scan) |
| 2884 | break; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2885 | } |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2886 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2887 | |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2888 | list_for_each_entry_safe(folio, next, &list, _deferred_list) { |
| 2889 | if (!folio_trylock(folio)) |
Kirill A. Shutemov | fa41b90 | 2018-03-22 16:17:31 -0700 | [diff] [blame] | 2890 | goto next; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2891 | /* split_huge_page() removes page from list on success */ |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2892 | if (!split_folio(folio)) |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2893 | split++; |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2894 | folio_unlock(folio); |
Kirill A. Shutemov | fa41b90 | 2018-03-22 16:17:31 -0700 | [diff] [blame] | 2895 | next: |
Matthew Wilcox (Oracle) | 4375a55 | 2023-01-11 14:29:10 +0000 | [diff] [blame] | 2896 | folio_put(folio); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2897 | } |
| 2898 | |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2899 | spin_lock_irqsave(&ds_queue->split_queue_lock, flags); |
| 2900 | list_splice_tail(&list, &ds_queue->split_queue); |
| 2901 | spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2902 | |
Kirill A. Shutemov | cb8d68e | 2016-02-02 16:57:12 -0800 | [diff] [blame] | 2903 | /* |
| 2904 | * Stop shrinker if we didn't split any page, but the queue is empty. |
| 2905 | * This can happen if pages were freed under us. |
| 2906 | */ |
Yang Shi | 364c1ee | 2019-09-23 15:38:06 -0700 | [diff] [blame] | 2907 | if (!split && list_empty(&ds_queue->split_queue)) |
Kirill A. Shutemov | cb8d68e | 2016-02-02 16:57:12 -0800 | [diff] [blame] | 2908 | return SHRINK_STOP; |
| 2909 | return split; |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2910 | } |
| 2911 | |
| 2912 | static struct shrinker deferred_split_shrinker = { |
| 2913 | .count_objects = deferred_split_count, |
| 2914 | .scan_objects = deferred_split_scan, |
| 2915 | .seeks = DEFAULT_SEEKS, |
Yang Shi | 87eaceb | 2019-09-23 15:38:15 -0700 | [diff] [blame] | 2916 | .flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | |
| 2917 | SHRINKER_NONSLAB, |
Kirill A. Shutemov | 9a98225 | 2016-01-15 16:54:17 -0800 | [diff] [blame] | 2918 | }; |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2919 | |
| 2920 | #ifdef CONFIG_DEBUG_FS |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 2921 | static void split_huge_pages_all(void) |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2922 | { |
| 2923 | struct zone *zone; |
| 2924 | struct page *page; |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2925 | struct folio *folio; |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2926 | unsigned long pfn, max_zone_pfn; |
| 2927 | unsigned long total = 0, split = 0; |
| 2928 | |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 2929 | pr_debug("Split all THPs\n"); |
Miaohe Lin | a17206d | 2022-07-04 21:21:57 +0800 | [diff] [blame] | 2930 | for_each_zone(zone) { |
| 2931 | if (!managed_zone(zone)) |
| 2932 | continue; |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2933 | max_zone_pfn = zone_end_pfn(zone); |
| 2934 | for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { |
Miaohe Lin | a17206d | 2022-07-04 21:21:57 +0800 | [diff] [blame] | 2935 | int nr_pages; |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2936 | |
Naoya Horiguchi | 2b7aa91 | 2022-09-08 13:11:50 +0900 | [diff] [blame] | 2937 | page = pfn_to_online_page(pfn); |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2938 | if (!page || PageTail(page)) |
| 2939 | continue; |
| 2940 | folio = page_folio(page); |
| 2941 | if (!folio_try_get(folio)) |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2942 | continue; |
| 2943 | |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2944 | if (unlikely(page_folio(page) != folio)) |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2945 | goto next; |
| 2946 | |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2947 | if (zone != folio_zone(folio)) |
| 2948 | goto next; |
| 2949 | |
| 2950 | if (!folio_test_large(folio) |
| 2951 | || folio_test_hugetlb(folio) |
| 2952 | || !folio_test_lru(folio)) |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2953 | goto next; |
| 2954 | |
| 2955 | total++; |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2956 | folio_lock(folio); |
| 2957 | nr_pages = folio_nr_pages(folio); |
| 2958 | if (!split_folio(folio)) |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2959 | split++; |
Miaohe Lin | a17206d | 2022-07-04 21:21:57 +0800 | [diff] [blame] | 2960 | pfn += nr_pages - 1; |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2961 | folio_unlock(folio); |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2962 | next: |
Kefeng Wang | 630e7c5 | 2022-12-29 20:25:03 +0800 | [diff] [blame] | 2963 | folio_put(folio); |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 2964 | cond_resched(); |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2965 | } |
| 2966 | } |
| 2967 | |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 2968 | pr_debug("%lu of %lu THP split\n", split, total); |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 2969 | } |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 2970 | |
| 2971 | static inline bool vma_not_suitable_for_thp_split(struct vm_area_struct *vma) |
| 2972 | { |
| 2973 | return vma_is_special_huge(vma) || (vma->vm_flags & VM_IO) || |
| 2974 | is_vm_hugetlb_page(vma); |
| 2975 | } |
| 2976 | |
| 2977 | static int split_huge_pages_pid(int pid, unsigned long vaddr_start, |
| 2978 | unsigned long vaddr_end) |
| 2979 | { |
| 2980 | int ret = 0; |
| 2981 | struct task_struct *task; |
| 2982 | struct mm_struct *mm; |
| 2983 | unsigned long total = 0, split = 0; |
| 2984 | unsigned long addr; |
| 2985 | |
| 2986 | vaddr_start &= PAGE_MASK; |
| 2987 | vaddr_end &= PAGE_MASK; |
| 2988 | |
| 2989 | /* Find the task_struct from pid */ |
| 2990 | rcu_read_lock(); |
| 2991 | task = find_task_by_vpid(pid); |
| 2992 | if (!task) { |
| 2993 | rcu_read_unlock(); |
| 2994 | ret = -ESRCH; |
| 2995 | goto out; |
| 2996 | } |
| 2997 | get_task_struct(task); |
| 2998 | rcu_read_unlock(); |
| 2999 | |
| 3000 | /* Find the mm_struct */ |
| 3001 | mm = get_task_mm(task); |
| 3002 | put_task_struct(task); |
| 3003 | |
| 3004 | if (!mm) { |
| 3005 | ret = -EINVAL; |
| 3006 | goto out; |
| 3007 | } |
| 3008 | |
| 3009 | pr_debug("Split huge pages in pid: %d, vaddr: [0x%lx - 0x%lx]\n", |
| 3010 | pid, vaddr_start, vaddr_end); |
| 3011 | |
| 3012 | mmap_read_lock(mm); |
| 3013 | /* |
| 3014 | * always increase addr by PAGE_SIZE, since we could have a PTE page |
| 3015 | * table filled with PTE-mapped THPs, each of which is distinct. |
| 3016 | */ |
| 3017 | for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) { |
Miaohe Lin | 74ba2b3 | 2022-07-04 21:21:52 +0800 | [diff] [blame] | 3018 | struct vm_area_struct *vma = vma_lookup(mm, addr); |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3019 | struct page *page; |
| 3020 | |
Miaohe Lin | 74ba2b3 | 2022-07-04 21:21:52 +0800 | [diff] [blame] | 3021 | if (!vma) |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3022 | break; |
| 3023 | |
| 3024 | /* skip special VMA and hugetlb VMA */ |
| 3025 | if (vma_not_suitable_for_thp_split(vma)) { |
| 3026 | addr = vma->vm_end; |
| 3027 | continue; |
| 3028 | } |
| 3029 | |
| 3030 | /* FOLL_DUMP to ignore special (like zero) pages */ |
Miaohe Lin | 87d2762 | 2022-03-22 14:45:29 -0700 | [diff] [blame] | 3031 | page = follow_page(vma, addr, FOLL_GET | FOLL_DUMP); |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3032 | |
Haiyue Wang | f7091ed | 2022-08-23 21:58:41 +0800 | [diff] [blame] | 3033 | if (IS_ERR_OR_NULL(page)) |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3034 | continue; |
| 3035 | |
| 3036 | if (!is_transparent_hugepage(page)) |
| 3037 | goto next; |
| 3038 | |
| 3039 | total++; |
Matthew Wilcox (Oracle) | d4b4084 | 2022-02-04 14:13:31 -0500 | [diff] [blame] | 3040 | if (!can_split_folio(page_folio(page), NULL)) |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3041 | goto next; |
| 3042 | |
| 3043 | if (!trylock_page(page)) |
| 3044 | goto next; |
| 3045 | |
| 3046 | if (!split_huge_page(page)) |
| 3047 | split++; |
| 3048 | |
| 3049 | unlock_page(page); |
| 3050 | next: |
| 3051 | put_page(page); |
| 3052 | cond_resched(); |
| 3053 | } |
| 3054 | mmap_read_unlock(mm); |
| 3055 | mmput(mm); |
| 3056 | |
| 3057 | pr_debug("%lu of %lu THP split\n", split, total); |
| 3058 | |
| 3059 | out: |
| 3060 | return ret; |
| 3061 | } |
| 3062 | |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3063 | static int split_huge_pages_in_file(const char *file_path, pgoff_t off_start, |
| 3064 | pgoff_t off_end) |
| 3065 | { |
| 3066 | struct filename *file; |
| 3067 | struct file *candidate; |
| 3068 | struct address_space *mapping; |
| 3069 | int ret = -EINVAL; |
| 3070 | pgoff_t index; |
| 3071 | int nr_pages = 1; |
| 3072 | unsigned long total = 0, split = 0; |
| 3073 | |
| 3074 | file = getname_kernel(file_path); |
| 3075 | if (IS_ERR(file)) |
| 3076 | return ret; |
| 3077 | |
| 3078 | candidate = file_open_name(file, O_RDONLY, 0); |
| 3079 | if (IS_ERR(candidate)) |
| 3080 | goto out; |
| 3081 | |
| 3082 | pr_debug("split file-backed THPs in file: %s, page offset: [0x%lx - 0x%lx]\n", |
| 3083 | file_path, off_start, off_end); |
| 3084 | |
| 3085 | mapping = candidate->f_mapping; |
| 3086 | |
| 3087 | for (index = off_start; index < off_end; index += nr_pages) { |
Christoph Hellwig | 1fb130b | 2023-03-07 15:34:04 +0100 | [diff] [blame] | 3088 | struct folio *folio = filemap_get_folio(mapping, index); |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3089 | |
| 3090 | nr_pages = 1; |
Christoph Hellwig | 66dabbb | 2023-03-07 15:34:10 +0100 | [diff] [blame] | 3091 | if (IS_ERR(folio)) |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3092 | continue; |
| 3093 | |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3094 | if (!folio_test_large(folio)) |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3095 | goto next; |
| 3096 | |
| 3097 | total++; |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3098 | nr_pages = folio_nr_pages(folio); |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3099 | |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3100 | if (!folio_trylock(folio)) |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3101 | goto next; |
| 3102 | |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3103 | if (!split_folio(folio)) |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3104 | split++; |
| 3105 | |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3106 | folio_unlock(folio); |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3107 | next: |
Matthew Wilcox (Oracle) | 9ee2c08 | 2022-10-19 19:33:29 +0100 | [diff] [blame] | 3108 | folio_put(folio); |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3109 | cond_resched(); |
| 3110 | } |
| 3111 | |
| 3112 | filp_close(candidate, NULL); |
| 3113 | ret = 0; |
| 3114 | |
| 3115 | pr_debug("%lu of %lu file-backed THP split\n", split, total); |
| 3116 | out: |
| 3117 | putname(file); |
| 3118 | return ret; |
| 3119 | } |
| 3120 | |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3121 | #define MAX_INPUT_BUF_SZ 255 |
| 3122 | |
| 3123 | static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, |
| 3124 | size_t count, loff_t *ppops) |
| 3125 | { |
| 3126 | static DEFINE_MUTEX(split_debug_mutex); |
| 3127 | ssize_t ret; |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3128 | /* hold pid, start_vaddr, end_vaddr or file_path, off_start, off_end */ |
| 3129 | char input_buf[MAX_INPUT_BUF_SZ]; |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3130 | int pid; |
| 3131 | unsigned long vaddr_start, vaddr_end; |
| 3132 | |
| 3133 | ret = mutex_lock_interruptible(&split_debug_mutex); |
| 3134 | if (ret) |
| 3135 | return ret; |
| 3136 | |
| 3137 | ret = -EFAULT; |
| 3138 | |
| 3139 | memset(input_buf, 0, MAX_INPUT_BUF_SZ); |
| 3140 | if (copy_from_user(input_buf, buf, min_t(size_t, count, MAX_INPUT_BUF_SZ))) |
| 3141 | goto out; |
| 3142 | |
| 3143 | input_buf[MAX_INPUT_BUF_SZ - 1] = '\0'; |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3144 | |
| 3145 | if (input_buf[0] == '/') { |
| 3146 | char *tok; |
| 3147 | char *buf = input_buf; |
| 3148 | char file_path[MAX_INPUT_BUF_SZ]; |
| 3149 | pgoff_t off_start = 0, off_end = 0; |
| 3150 | size_t input_len = strlen(input_buf); |
| 3151 | |
| 3152 | tok = strsep(&buf, ","); |
| 3153 | if (tok) { |
Matthew Wilcox (Oracle) | 1212e00 | 2021-06-30 18:52:11 -0700 | [diff] [blame] | 3154 | strcpy(file_path, tok); |
Zi Yan | fbe3750 | 2021-05-04 18:34:26 -0700 | [diff] [blame] | 3155 | } else { |
| 3156 | ret = -EINVAL; |
| 3157 | goto out; |
| 3158 | } |
| 3159 | |
| 3160 | ret = sscanf(buf, "0x%lx,0x%lx", &off_start, &off_end); |
| 3161 | if (ret != 2) { |
| 3162 | ret = -EINVAL; |
| 3163 | goto out; |
| 3164 | } |
| 3165 | ret = split_huge_pages_in_file(file_path, off_start, off_end); |
| 3166 | if (!ret) |
| 3167 | ret = input_len; |
| 3168 | |
| 3169 | goto out; |
| 3170 | } |
| 3171 | |
Zi Yan | fa6c023 | 2021-05-04 18:34:23 -0700 | [diff] [blame] | 3172 | ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); |
| 3173 | if (ret == 1 && pid == 1) { |
| 3174 | split_huge_pages_all(); |
| 3175 | ret = strlen(input_buf); |
| 3176 | goto out; |
| 3177 | } else if (ret != 3) { |
| 3178 | ret = -EINVAL; |
| 3179 | goto out; |
| 3180 | } |
| 3181 | |
| 3182 | ret = split_huge_pages_pid(pid, vaddr_start, vaddr_end); |
| 3183 | if (!ret) |
| 3184 | ret = strlen(input_buf); |
| 3185 | out: |
| 3186 | mutex_unlock(&split_debug_mutex); |
| 3187 | return ret; |
| 3188 | |
| 3189 | } |
| 3190 | |
| 3191 | static const struct file_operations split_huge_pages_fops = { |
| 3192 | .owner = THIS_MODULE, |
| 3193 | .write = split_huge_pages_write, |
| 3194 | .llseek = no_llseek, |
| 3195 | }; |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 3196 | |
| 3197 | static int __init split_huge_pages_debugfs(void) |
| 3198 | { |
Greg Kroah-Hartman | d9f7979 | 2019-03-05 15:46:09 -0800 | [diff] [blame] | 3199 | debugfs_create_file("split_huge_pages", 0200, NULL, NULL, |
| 3200 | &split_huge_pages_fops); |
Kirill A. Shutemov | 49071d4 | 2016-01-15 16:54:40 -0800 | [diff] [blame] | 3201 | return 0; |
| 3202 | } |
| 3203 | late_initcall(split_huge_pages_debugfs); |
| 3204 | #endif |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3205 | |
| 3206 | #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION |
David Hildenbrand | 7f5abe6 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3207 | int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3208 | struct page *page) |
| 3209 | { |
| 3210 | struct vm_area_struct *vma = pvmw->vma; |
| 3211 | struct mm_struct *mm = vma->vm_mm; |
| 3212 | unsigned long address = pvmw->address; |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3213 | bool anon_exclusive; |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3214 | pmd_t pmdval; |
| 3215 | swp_entry_t entry; |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 3216 | pmd_t pmdswp; |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3217 | |
| 3218 | if (!(pvmw->pmd && !pvmw->pte)) |
David Hildenbrand | 7f5abe6 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3219 | return 0; |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3220 | |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3221 | flush_cache_range(vma, address, address + HPAGE_PMD_SIZE); |
Huang Ying | 8a8683a | 2020-03-05 22:28:29 -0800 | [diff] [blame] | 3222 | pmdval = pmdp_invalidate(vma, address, pvmw->pmd); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3223 | |
David Hildenbrand | 088b8aa | 2022-09-01 10:35:59 +0200 | [diff] [blame] | 3224 | /* See page_try_share_anon_rmap(): invalidate PMD first. */ |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3225 | anon_exclusive = PageAnon(page) && PageAnonExclusive(page); |
| 3226 | if (anon_exclusive && page_try_share_anon_rmap(page)) { |
| 3227 | set_pmd_at(mm, address, pvmw->pmd, pmdval); |
David Hildenbrand | 7f5abe6 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3228 | return -EBUSY; |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3229 | } |
| 3230 | |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3231 | if (pmd_dirty(pmdval)) |
| 3232 | set_page_dirty(page); |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 3233 | if (pmd_write(pmdval)) |
| 3234 | entry = make_writable_migration_entry(page_to_pfn(page)); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3235 | else if (anon_exclusive) |
| 3236 | entry = make_readable_exclusive_migration_entry(page_to_pfn(page)); |
Alistair Popple | 4dd845b | 2021-06-30 18:54:09 -0700 | [diff] [blame] | 3237 | else |
| 3238 | entry = make_readable_migration_entry(page_to_pfn(page)); |
Peter Xu | 2e34687 | 2022-08-11 12:13:29 -0400 | [diff] [blame] | 3239 | if (pmd_young(pmdval)) |
| 3240 | entry = make_migration_entry_young(entry); |
| 3241 | if (pmd_dirty(pmdval)) |
| 3242 | entry = make_migration_entry_dirty(entry); |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 3243 | pmdswp = swp_entry_to_pmd(entry); |
| 3244 | if (pmd_soft_dirty(pmdval)) |
| 3245 | pmdswp = pmd_swp_mksoft_dirty(pmdswp); |
David Hildenbrand | 24bf08c | 2023-04-05 18:02:35 +0200 | [diff] [blame] | 3246 | if (pmd_uffd_wp(pmdval)) |
| 3247 | pmdswp = pmd_swp_mkuffd_wp(pmdswp); |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 3248 | set_pmd_at(mm, address, pvmw->pmd, pmdswp); |
Hugh Dickins | cea86fe | 2022-02-14 18:26:39 -0800 | [diff] [blame] | 3249 | page_remove_rmap(page, vma, true); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3250 | put_page(page); |
Anshuman Khandual | 283fd6f | 2022-03-24 18:09:58 -0700 | [diff] [blame] | 3251 | trace_set_migration_pmd(address, pmd_val(pmdswp)); |
David Hildenbrand | 7f5abe6 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3252 | |
| 3253 | return 0; |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3254 | } |
| 3255 | |
| 3256 | void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) |
| 3257 | { |
| 3258 | struct vm_area_struct *vma = pvmw->vma; |
| 3259 | struct mm_struct *mm = vma->vm_mm; |
| 3260 | unsigned long address = pvmw->address; |
Miaohe Lin | 4fba8f2 | 2022-07-04 21:21:51 +0800 | [diff] [blame] | 3261 | unsigned long haddr = address & HPAGE_PMD_MASK; |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3262 | pmd_t pmde; |
| 3263 | swp_entry_t entry; |
| 3264 | |
| 3265 | if (!(pvmw->pmd && !pvmw->pte)) |
| 3266 | return; |
| 3267 | |
| 3268 | entry = pmd_to_swp_entry(*pvmw->pmd); |
| 3269 | get_page(new); |
Peter Xu | 2e34687 | 2022-08-11 12:13:29 -0400 | [diff] [blame] | 3270 | pmde = mk_huge_pmd(new, READ_ONCE(vma->vm_page_prot)); |
Naoya Horiguchi | ab6e3d0 | 2017-09-08 16:11:04 -0700 | [diff] [blame] | 3271 | if (pmd_swp_soft_dirty(*pvmw->pmd)) |
| 3272 | pmde = pmd_mksoft_dirty(pmde); |
David Hildenbrand | 3c811f7 | 2023-04-11 16:25:10 +0200 | [diff] [blame] | 3273 | if (is_writable_migration_entry(entry)) |
David Hildenbrand | f3ebdf0 | 2023-04-18 16:21:13 +0200 | [diff] [blame] | 3274 | pmde = pmd_mkwrite(pmde); |
Peter Xu | 8f34f1e | 2021-06-30 18:49:02 -0700 | [diff] [blame] | 3275 | if (pmd_swp_uffd_wp(*pvmw->pmd)) |
Peter Xu | f1eb1ba | 2022-12-14 15:15:33 -0500 | [diff] [blame] | 3276 | pmde = pmd_mkuffd_wp(pmde); |
Peter Xu | 2e34687 | 2022-08-11 12:13:29 -0400 | [diff] [blame] | 3277 | if (!is_migration_entry_young(entry)) |
| 3278 | pmde = pmd_mkold(pmde); |
| 3279 | /* NOTE: this may contain setting soft-dirty on some archs */ |
| 3280 | if (PageDirty(new) && is_migration_entry_dirty(entry)) |
| 3281 | pmde = pmd_mkdirty(pmde); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3282 | |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3283 | if (PageAnon(new)) { |
| 3284 | rmap_t rmap_flags = RMAP_COMPOUND; |
| 3285 | |
| 3286 | if (!is_readable_migration_entry(entry)) |
| 3287 | rmap_flags |= RMAP_EXCLUSIVE; |
| 3288 | |
Miaohe Lin | 4fba8f2 | 2022-07-04 21:21:51 +0800 | [diff] [blame] | 3289 | page_add_anon_rmap(new, vma, haddr, rmap_flags); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3290 | } else { |
Hugh Dickins | cea86fe | 2022-02-14 18:26:39 -0800 | [diff] [blame] | 3291 | page_add_file_rmap(new, vma, true); |
David Hildenbrand | 6c28760 | 2022-05-09 18:20:44 -0700 | [diff] [blame] | 3292 | } |
| 3293 | VM_BUG_ON(pmd_write(pmde) && PageAnon(new) && !PageAnonExclusive(new)); |
Miaohe Lin | 4fba8f2 | 2022-07-04 21:21:51 +0800 | [diff] [blame] | 3294 | set_pmd_at(mm, haddr, pvmw->pmd, pmde); |
Muchun Song | 5cbcf22 | 2022-03-22 14:41:53 -0700 | [diff] [blame] | 3295 | |
| 3296 | /* No need to invalidate - it was non-present before */ |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3297 | update_mmu_cache_pmd(vma, address, pvmw->pmd); |
Anshuman Khandual | 283fd6f | 2022-03-24 18:09:58 -0700 | [diff] [blame] | 3298 | trace_remove_migration_pmd(address, pmd_val(pmde)); |
Zi Yan | 616b837 | 2017-09-08 16:10:57 -0700 | [diff] [blame] | 3299 | } |
| 3300 | #endif |