| /* |
| * linux/mm/memory_hotplug.c |
| * |
| * Copyright (C) |
| */ |
| |
| #include <linux/stddef.h> |
| #include <linux/mm.h> |
| #include <linux/swap.h> |
| #include <linux/interrupt.h> |
| #include <linux/pagemap.h> |
| #include <linux/bootmem.h> |
| #include <linux/compiler.h> |
| #include <linux/export.h> |
| #include <linux/pagevec.h> |
| #include <linux/writeback.h> |
| #include <linux/slab.h> |
| #include <linux/sysctl.h> |
| #include <linux/cpu.h> |
| #include <linux/memory.h> |
| #include <linux/memory_hotplug.h> |
| #include <linux/highmem.h> |
| #include <linux/vmalloc.h> |
| #include <linux/ioport.h> |
| #include <linux/delay.h> |
| #include <linux/migrate.h> |
| #include <linux/page-isolation.h> |
| #include <linux/pfn.h> |
| #include <linux/suspend.h> |
| #include <linux/mm_inline.h> |
| #include <linux/firmware-map.h> |
| #include <linux/stop_machine.h> |
| #include <linux/hugetlb.h> |
| #include <linux/memblock.h> |
| |
| #include <asm/tlbflush.h> |
| |
| #include "internal.h" |
| |
| /* |
| * online_page_callback contains pointer to current page onlining function. |
| * Initially it is generic_online_page(). If it is required it could be |
| * changed by calling set_online_page_callback() for callback registration |
| * and restore_online_page_callback() for generic callback restore. |
| */ |
| |
| static void generic_online_page(struct page *page); |
| |
| static online_page_callback_t online_page_callback = generic_online_page; |
| |
| DEFINE_MUTEX(mem_hotplug_mutex); |
| |
| void lock_memory_hotplug(void) |
| { |
| mutex_lock(&mem_hotplug_mutex); |
| } |
| |
| void unlock_memory_hotplug(void) |
| { |
| mutex_unlock(&mem_hotplug_mutex); |
| } |
| |
| |
| /* add this memory to iomem resource */ |
| static struct resource *register_memory_resource(u64 start, u64 size) |
| { |
| struct resource *res; |
| res = kzalloc(sizeof(struct resource), GFP_KERNEL); |
| BUG_ON(!res); |
| |
| res->name = "System RAM"; |
| res->start = start; |
| res->end = start + size - 1; |
| res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; |
| if (request_resource(&iomem_resource, res) < 0) { |
| pr_debug("System RAM resource %pR cannot be added\n", res); |
| kfree(res); |
| res = NULL; |
| } |
| return res; |
| } |
| |
| static void release_memory_resource(struct resource *res) |
| { |
| if (!res) |
| return; |
| release_resource(res); |
| kfree(res); |
| return; |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE |
| void get_page_bootmem(unsigned long info, struct page *page, |
| unsigned long type) |
| { |
| page->lru.next = (struct list_head *) type; |
| SetPagePrivate(page); |
| set_page_private(page, info); |
| atomic_inc(&page->_count); |
| } |
| |
| void put_page_bootmem(struct page *page) |
| { |
| unsigned long type; |
| |
| type = (unsigned long) page->lru.next; |
| BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || |
| type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); |
| |
| if (atomic_dec_return(&page->_count) == 1) { |
| ClearPagePrivate(page); |
| set_page_private(page, 0); |
| INIT_LIST_HEAD(&page->lru); |
| free_reserved_page(page); |
| } |
| } |
| |
| #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE |
| #ifndef CONFIG_SPARSEMEM_VMEMMAP |
| static void register_page_bootmem_info_section(unsigned long start_pfn) |
| { |
| unsigned long *usemap, mapsize, section_nr, i; |
| struct mem_section *ms; |
| struct page *page, *memmap; |
| |
| section_nr = pfn_to_section_nr(start_pfn); |
| ms = __nr_to_section(section_nr); |
| |
| /* Get section's memmap address */ |
| memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); |
| |
| /* |
| * Get page for the memmap's phys address |
| * XXX: need more consideration for sparse_vmemmap... |
| */ |
| page = virt_to_page(memmap); |
| mapsize = sizeof(struct page) * PAGES_PER_SECTION; |
| mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; |
| |
| /* remember memmap's page */ |
| for (i = 0; i < mapsize; i++, page++) |
| get_page_bootmem(section_nr, page, SECTION_INFO); |
| |
| usemap = __nr_to_section(section_nr)->pageblock_flags; |
| page = virt_to_page(usemap); |
| |
| mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; |
| |
| for (i = 0; i < mapsize; i++, page++) |
| get_page_bootmem(section_nr, page, MIX_SECTION_INFO); |
| |
| } |
| #else /* CONFIG_SPARSEMEM_VMEMMAP */ |
| static void register_page_bootmem_info_section(unsigned long start_pfn) |
| { |
| unsigned long *usemap, mapsize, section_nr, i; |
| struct mem_section *ms; |
| struct page *page, *memmap; |
| |
| if (!pfn_valid(start_pfn)) |
| return; |
| |
| section_nr = pfn_to_section_nr(start_pfn); |
| ms = __nr_to_section(section_nr); |
| |
| memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); |
| |
| register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); |
| |
| usemap = __nr_to_section(section_nr)->pageblock_flags; |
| page = virt_to_page(usemap); |
| |
| mapsize = PAGE_ALIGN(usemap_size()) >> PAGE_SHIFT; |
| |
| for (i = 0; i < mapsize; i++, page++) |
| get_page_bootmem(section_nr, page, MIX_SECTION_INFO); |
| } |
| #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ |
| |
| void register_page_bootmem_info_node(struct pglist_data *pgdat) |
| { |
| unsigned long i, pfn, end_pfn, nr_pages; |
| int node = pgdat->node_id; |
| struct page *page; |
| struct zone *zone; |
| |
| nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; |
| page = virt_to_page(pgdat); |
| |
| for (i = 0; i < nr_pages; i++, page++) |
| get_page_bootmem(node, page, NODE_INFO); |
| |
| zone = &pgdat->node_zones[0]; |
| for (; zone < pgdat->node_zones + MAX_NR_ZONES - 1; zone++) { |
| if (zone_is_initialized(zone)) { |
| nr_pages = zone->wait_table_hash_nr_entries |
| * sizeof(wait_queue_head_t); |
| nr_pages = PAGE_ALIGN(nr_pages) >> PAGE_SHIFT; |
| page = virt_to_page(zone->wait_table); |
| |
| for (i = 0; i < nr_pages; i++, page++) |
| get_page_bootmem(node, page, NODE_INFO); |
| } |
| } |
| |
| pfn = pgdat->node_start_pfn; |
| end_pfn = pgdat_end_pfn(pgdat); |
| |
| /* register section info */ |
| for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
| /* |
| * Some platforms can assign the same pfn to multiple nodes - on |
| * node0 as well as nodeN. To avoid registering a pfn against |
| * multiple nodes we check that this pfn does not already |
| * reside in some other nodes. |
| */ |
| if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) |
| register_page_bootmem_info_section(pfn); |
| } |
| } |
| #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ |
| |
| static void grow_zone_span(struct zone *zone, unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long old_zone_end_pfn; |
| |
| zone_span_writelock(zone); |
| |
| old_zone_end_pfn = zone_end_pfn(zone); |
| if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) |
| zone->zone_start_pfn = start_pfn; |
| |
| zone->spanned_pages = max(old_zone_end_pfn, end_pfn) - |
| zone->zone_start_pfn; |
| |
| zone_span_writeunlock(zone); |
| } |
| |
| static void resize_zone(struct zone *zone, unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| zone_span_writelock(zone); |
| |
| if (end_pfn - start_pfn) { |
| zone->zone_start_pfn = start_pfn; |
| zone->spanned_pages = end_pfn - start_pfn; |
| } else { |
| /* |
| * make it consist as free_area_init_core(), |
| * if spanned_pages = 0, then keep start_pfn = 0 |
| */ |
| zone->zone_start_pfn = 0; |
| zone->spanned_pages = 0; |
| } |
| |
| zone_span_writeunlock(zone); |
| } |
| |
| static void fix_zone_id(struct zone *zone, unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| enum zone_type zid = zone_idx(zone); |
| int nid = zone->zone_pgdat->node_id; |
| unsigned long pfn; |
| |
| for (pfn = start_pfn; pfn < end_pfn; pfn++) |
| set_page_links(pfn_to_page(pfn), zid, nid, pfn); |
| } |
| |
| /* Can fail with -ENOMEM from allocating a wait table with vmalloc() or |
| * alloc_bootmem_node_nopanic() */ |
| static int __ref ensure_zone_is_initialized(struct zone *zone, |
| unsigned long start_pfn, unsigned long num_pages) |
| { |
| if (!zone_is_initialized(zone)) |
| return init_currently_empty_zone(zone, start_pfn, num_pages, |
| MEMMAP_HOTPLUG); |
| return 0; |
| } |
| |
| static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2, |
| unsigned long start_pfn, unsigned long end_pfn) |
| { |
| int ret; |
| unsigned long flags; |
| unsigned long z1_start_pfn; |
| |
| ret = ensure_zone_is_initialized(z1, start_pfn, end_pfn - start_pfn); |
| if (ret) |
| return ret; |
| |
| pgdat_resize_lock(z1->zone_pgdat, &flags); |
| |
| /* can't move pfns which are higher than @z2 */ |
| if (end_pfn > zone_end_pfn(z2)) |
| goto out_fail; |
| /* the move out part must be at the left most of @z2 */ |
| if (start_pfn > z2->zone_start_pfn) |
| goto out_fail; |
| /* must included/overlap */ |
| if (end_pfn <= z2->zone_start_pfn) |
| goto out_fail; |
| |
| /* use start_pfn for z1's start_pfn if z1 is empty */ |
| if (!zone_is_empty(z1)) |
| z1_start_pfn = z1->zone_start_pfn; |
| else |
| z1_start_pfn = start_pfn; |
| |
| resize_zone(z1, z1_start_pfn, end_pfn); |
| resize_zone(z2, end_pfn, zone_end_pfn(z2)); |
| |
| pgdat_resize_unlock(z1->zone_pgdat, &flags); |
| |
| fix_zone_id(z1, start_pfn, end_pfn); |
| |
| return 0; |
| out_fail: |
| pgdat_resize_unlock(z1->zone_pgdat, &flags); |
| return -1; |
| } |
| |
| static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2, |
| unsigned long start_pfn, unsigned long end_pfn) |
| { |
| int ret; |
| unsigned long flags; |
| unsigned long z2_end_pfn; |
| |
| ret = ensure_zone_is_initialized(z2, start_pfn, end_pfn - start_pfn); |
| if (ret) |
| return ret; |
| |
| pgdat_resize_lock(z1->zone_pgdat, &flags); |
| |
| /* can't move pfns which are lower than @z1 */ |
| if (z1->zone_start_pfn > start_pfn) |
| goto out_fail; |
| /* the move out part mast at the right most of @z1 */ |
| if (zone_end_pfn(z1) > end_pfn) |
| goto out_fail; |
| /* must included/overlap */ |
| if (start_pfn >= zone_end_pfn(z1)) |
| goto out_fail; |
| |
| /* use end_pfn for z2's end_pfn if z2 is empty */ |
| if (!zone_is_empty(z2)) |
| z2_end_pfn = zone_end_pfn(z2); |
| else |
| z2_end_pfn = end_pfn; |
| |
| resize_zone(z1, z1->zone_start_pfn, start_pfn); |
| resize_zone(z2, start_pfn, z2_end_pfn); |
| |
| pgdat_resize_unlock(z1->zone_pgdat, &flags); |
| |
| fix_zone_id(z2, start_pfn, end_pfn); |
| |
| return 0; |
| out_fail: |
| pgdat_resize_unlock(z1->zone_pgdat, &flags); |
| return -1; |
| } |
| |
| static void grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long old_pgdat_end_pfn = pgdat_end_pfn(pgdat); |
| |
| if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) |
| pgdat->node_start_pfn = start_pfn; |
| |
| pgdat->node_spanned_pages = max(old_pgdat_end_pfn, end_pfn) - |
| pgdat->node_start_pfn; |
| } |
| |
| static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn) |
| { |
| struct pglist_data *pgdat = zone->zone_pgdat; |
| int nr_pages = PAGES_PER_SECTION; |
| int nid = pgdat->node_id; |
| int zone_type; |
| unsigned long flags; |
| int ret; |
| |
| zone_type = zone - pgdat->node_zones; |
| ret = ensure_zone_is_initialized(zone, phys_start_pfn, nr_pages); |
| if (ret) |
| return ret; |
| |
| pgdat_resize_lock(zone->zone_pgdat, &flags); |
| grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages); |
| grow_pgdat_span(zone->zone_pgdat, phys_start_pfn, |
| phys_start_pfn + nr_pages); |
| pgdat_resize_unlock(zone->zone_pgdat, &flags); |
| memmap_init_zone(nr_pages, nid, zone_type, |
| phys_start_pfn, MEMMAP_HOTPLUG); |
| return 0; |
| } |
| |
| static int __meminit __add_section(int nid, struct zone *zone, |
| unsigned long phys_start_pfn) |
| { |
| int ret; |
| |
| if (pfn_valid(phys_start_pfn)) |
| return -EEXIST; |
| |
| ret = sparse_add_one_section(zone, phys_start_pfn); |
| |
| if (ret < 0) |
| return ret; |
| |
| ret = __add_zone(zone, phys_start_pfn); |
| |
| if (ret < 0) |
| return ret; |
| |
| return register_new_memory(nid, __pfn_to_section(phys_start_pfn)); |
| } |
| |
| /* |
| * Reasonably generic function for adding memory. It is |
| * expected that archs that support memory hotplug will |
| * call this function after deciding the zone to which to |
| * add the new pages. |
| */ |
| int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn, |
| unsigned long nr_pages) |
| { |
| unsigned long i; |
| int err = 0; |
| int start_sec, end_sec; |
| /* during initialize mem_map, align hot-added range to section */ |
| start_sec = pfn_to_section_nr(phys_start_pfn); |
| end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1); |
| |
| for (i = start_sec; i <= end_sec; i++) { |
| err = __add_section(nid, zone, i << PFN_SECTION_SHIFT); |
| |
| /* |
| * EEXIST is finally dealt with by ioresource collision |
| * check. see add_memory() => register_memory_resource() |
| * Warning will be printed if there is collision. |
| */ |
| if (err && (err != -EEXIST)) |
| break; |
| err = 0; |
| } |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(__add_pages); |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ |
| static int find_smallest_section_pfn(int nid, struct zone *zone, |
| unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| struct mem_section *ms; |
| |
| for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SECTION) { |
| ms = __pfn_to_section(start_pfn); |
| |
| if (unlikely(!valid_section(ms))) |
| continue; |
| |
| if (unlikely(pfn_to_nid(start_pfn) != nid)) |
| continue; |
| |
| if (zone && zone != page_zone(pfn_to_page(start_pfn))) |
| continue; |
| |
| return start_pfn; |
| } |
| |
| return 0; |
| } |
| |
| /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ |
| static int find_biggest_section_pfn(int nid, struct zone *zone, |
| unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| struct mem_section *ms; |
| unsigned long pfn; |
| |
| /* pfn is the end pfn of a memory section. */ |
| pfn = end_pfn - 1; |
| for (; pfn >= start_pfn; pfn -= PAGES_PER_SECTION) { |
| ms = __pfn_to_section(pfn); |
| |
| if (unlikely(!valid_section(ms))) |
| continue; |
| |
| if (unlikely(pfn_to_nid(pfn) != nid)) |
| continue; |
| |
| if (zone && zone != page_zone(pfn_to_page(pfn))) |
| continue; |
| |
| return pfn; |
| } |
| |
| return 0; |
| } |
| |
| static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long zone_start_pfn = zone->zone_start_pfn; |
| unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ |
| unsigned long zone_end_pfn = z; |
| unsigned long pfn; |
| struct mem_section *ms; |
| int nid = zone_to_nid(zone); |
| |
| zone_span_writelock(zone); |
| if (zone_start_pfn == start_pfn) { |
| /* |
| * If the section is smallest section in the zone, it need |
| * shrink zone->zone_start_pfn and zone->zone_spanned_pages. |
| * In this case, we find second smallest valid mem_section |
| * for shrinking zone. |
| */ |
| pfn = find_smallest_section_pfn(nid, zone, end_pfn, |
| zone_end_pfn); |
| if (pfn) { |
| zone->zone_start_pfn = pfn; |
| zone->spanned_pages = zone_end_pfn - pfn; |
| } |
| } else if (zone_end_pfn == end_pfn) { |
| /* |
| * If the section is biggest section in the zone, it need |
| * shrink zone->spanned_pages. |
| * In this case, we find second biggest valid mem_section for |
| * shrinking zone. |
| */ |
| pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, |
| start_pfn); |
| if (pfn) |
| zone->spanned_pages = pfn - zone_start_pfn + 1; |
| } |
| |
| /* |
| * The section is not biggest or smallest mem_section in the zone, it |
| * only creates a hole in the zone. So in this case, we need not |
| * change the zone. But perhaps, the zone has only hole data. Thus |
| * it check the zone has only hole or not. |
| */ |
| pfn = zone_start_pfn; |
| for (; pfn < zone_end_pfn; pfn += PAGES_PER_SECTION) { |
| ms = __pfn_to_section(pfn); |
| |
| if (unlikely(!valid_section(ms))) |
| continue; |
| |
| if (page_zone(pfn_to_page(pfn)) != zone) |
| continue; |
| |
| /* If the section is current section, it continues the loop */ |
| if (start_pfn == pfn) |
| continue; |
| |
| /* If we find valid section, we have nothing to do */ |
| zone_span_writeunlock(zone); |
| return; |
| } |
| |
| /* The zone has no valid section */ |
| zone->zone_start_pfn = 0; |
| zone->spanned_pages = 0; |
| zone_span_writeunlock(zone); |
| } |
| |
| static void shrink_pgdat_span(struct pglist_data *pgdat, |
| unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pgdat_start_pfn = pgdat->node_start_pfn; |
| unsigned long p = pgdat_end_pfn(pgdat); /* pgdat_end_pfn namespace clash */ |
| unsigned long pgdat_end_pfn = p; |
| unsigned long pfn; |
| struct mem_section *ms; |
| int nid = pgdat->node_id; |
| |
| if (pgdat_start_pfn == start_pfn) { |
| /* |
| * If the section is smallest section in the pgdat, it need |
| * shrink pgdat->node_start_pfn and pgdat->node_spanned_pages. |
| * In this case, we find second smallest valid mem_section |
| * for shrinking zone. |
| */ |
| pfn = find_smallest_section_pfn(nid, NULL, end_pfn, |
| pgdat_end_pfn); |
| if (pfn) { |
| pgdat->node_start_pfn = pfn; |
| pgdat->node_spanned_pages = pgdat_end_pfn - pfn; |
| } |
| } else if (pgdat_end_pfn == end_pfn) { |
| /* |
| * If the section is biggest section in the pgdat, it need |
| * shrink pgdat->node_spanned_pages. |
| * In this case, we find second biggest valid mem_section for |
| * shrinking zone. |
| */ |
| pfn = find_biggest_section_pfn(nid, NULL, pgdat_start_pfn, |
| start_pfn); |
| if (pfn) |
| pgdat->node_spanned_pages = pfn - pgdat_start_pfn + 1; |
| } |
| |
| /* |
| * If the section is not biggest or smallest mem_section in the pgdat, |
| * it only creates a hole in the pgdat. So in this case, we need not |
| * change the pgdat. |
| * But perhaps, the pgdat has only hole data. Thus it check the pgdat |
| * has only hole or not. |
| */ |
| pfn = pgdat_start_pfn; |
| for (; pfn < pgdat_end_pfn; pfn += PAGES_PER_SECTION) { |
| ms = __pfn_to_section(pfn); |
| |
| if (unlikely(!valid_section(ms))) |
| continue; |
| |
| if (pfn_to_nid(pfn) != nid) |
| continue; |
| |
| /* If the section is current section, it continues the loop */ |
| if (start_pfn == pfn) |
| continue; |
| |
| /* If we find valid section, we have nothing to do */ |
| return; |
| } |
| |
| /* The pgdat has no valid section */ |
| pgdat->node_start_pfn = 0; |
| pgdat->node_spanned_pages = 0; |
| } |
| |
| static void __remove_zone(struct zone *zone, unsigned long start_pfn) |
| { |
| struct pglist_data *pgdat = zone->zone_pgdat; |
| int nr_pages = PAGES_PER_SECTION; |
| int zone_type; |
| unsigned long flags; |
| |
| zone_type = zone - pgdat->node_zones; |
| |
| pgdat_resize_lock(zone->zone_pgdat, &flags); |
| shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); |
| shrink_pgdat_span(pgdat, start_pfn, start_pfn + nr_pages); |
| pgdat_resize_unlock(zone->zone_pgdat, &flags); |
| } |
| |
| static int __remove_section(struct zone *zone, struct mem_section *ms) |
| { |
| unsigned long start_pfn; |
| int scn_nr; |
| int ret = -EINVAL; |
| |
| if (!valid_section(ms)) |
| return ret; |
| |
| ret = unregister_memory_section(ms); |
| if (ret) |
| return ret; |
| |
| scn_nr = __section_nr(ms); |
| start_pfn = section_nr_to_pfn(scn_nr); |
| __remove_zone(zone, start_pfn); |
| |
| sparse_remove_one_section(zone, ms); |
| return 0; |
| } |
| |
| /** |
| * __remove_pages() - remove sections of pages from a zone |
| * @zone: zone from which pages need to be removed |
| * @phys_start_pfn: starting pageframe (must be aligned to start of a section) |
| * @nr_pages: number of pages to remove (must be multiple of section size) |
| * |
| * Generic helper function to remove section mappings and sysfs entries |
| * for the section of the memory we are removing. Caller needs to make |
| * sure that pages are marked reserved and zones are adjust properly by |
| * calling offline_pages(). |
| */ |
| int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, |
| unsigned long nr_pages) |
| { |
| unsigned long i; |
| int sections_to_remove; |
| resource_size_t start, size; |
| int ret = 0; |
| |
| /* |
| * We can only remove entire sections |
| */ |
| BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); |
| BUG_ON(nr_pages % PAGES_PER_SECTION); |
| |
| start = phys_start_pfn << PAGE_SHIFT; |
| size = nr_pages * PAGE_SIZE; |
| ret = release_mem_region_adjustable(&iomem_resource, start, size); |
| if (ret) { |
| resource_size_t endres = start + size - 1; |
| |
| pr_warn("Unable to release resource <%pa-%pa> (%d)\n", |
| &start, &endres, ret); |
| } |
| |
| sections_to_remove = nr_pages / PAGES_PER_SECTION; |
| for (i = 0; i < sections_to_remove; i++) { |
| unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; |
| ret = __remove_section(zone, __pfn_to_section(pfn)); |
| if (ret) |
| break; |
| } |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(__remove_pages); |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |
| |
| int set_online_page_callback(online_page_callback_t callback) |
| { |
| int rc = -EINVAL; |
| |
| lock_memory_hotplug(); |
| |
| if (online_page_callback == generic_online_page) { |
| online_page_callback = callback; |
| rc = 0; |
| } |
| |
| unlock_memory_hotplug(); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(set_online_page_callback); |
| |
| int restore_online_page_callback(online_page_callback_t callback) |
| { |
| int rc = -EINVAL; |
| |
| lock_memory_hotplug(); |
| |
| if (online_page_callback == callback) { |
| online_page_callback = generic_online_page; |
| rc = 0; |
| } |
| |
| unlock_memory_hotplug(); |
| |
| return rc; |
| } |
| EXPORT_SYMBOL_GPL(restore_online_page_callback); |
| |
| void __online_page_set_limits(struct page *page) |
| { |
| } |
| EXPORT_SYMBOL_GPL(__online_page_set_limits); |
| |
| void __online_page_increment_counters(struct page *page) |
| { |
| adjust_managed_page_count(page, 1); |
| } |
| EXPORT_SYMBOL_GPL(__online_page_increment_counters); |
| |
| void __online_page_free(struct page *page) |
| { |
| __free_reserved_page(page); |
| } |
| EXPORT_SYMBOL_GPL(__online_page_free); |
| |
| static void generic_online_page(struct page *page) |
| { |
| __online_page_set_limits(page); |
| __online_page_increment_counters(page); |
| __online_page_free(page); |
| } |
| |
| static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, |
| void *arg) |
| { |
| unsigned long i; |
| unsigned long onlined_pages = *(unsigned long *)arg; |
| struct page *page; |
| if (PageReserved(pfn_to_page(start_pfn))) |
| for (i = 0; i < nr_pages; i++) { |
| page = pfn_to_page(start_pfn + i); |
| (*online_page_callback)(page); |
| onlined_pages++; |
| } |
| *(unsigned long *)arg = onlined_pages; |
| return 0; |
| } |
| |
| #ifdef CONFIG_MOVABLE_NODE |
| /* |
| * When CONFIG_MOVABLE_NODE, we permit onlining of a node which doesn't have |
| * normal memory. |
| */ |
| static bool can_online_high_movable(struct zone *zone) |
| { |
| return true; |
| } |
| #else /* CONFIG_MOVABLE_NODE */ |
| /* ensure every online node has NORMAL memory */ |
| static bool can_online_high_movable(struct zone *zone) |
| { |
| return node_state(zone_to_nid(zone), N_NORMAL_MEMORY); |
| } |
| #endif /* CONFIG_MOVABLE_NODE */ |
| |
| /* check which state of node_states will be changed when online memory */ |
| static void node_states_check_changes_online(unsigned long nr_pages, |
| struct zone *zone, struct memory_notify *arg) |
| { |
| int nid = zone_to_nid(zone); |
| enum zone_type zone_last = ZONE_NORMAL; |
| |
| /* |
| * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] |
| * contains nodes which have zones of 0...ZONE_NORMAL, |
| * set zone_last to ZONE_NORMAL. |
| * |
| * If we don't have HIGHMEM nor movable node, |
| * node_states[N_NORMAL_MEMORY] contains nodes which have zones of |
| * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. |
| */ |
| if (N_MEMORY == N_NORMAL_MEMORY) |
| zone_last = ZONE_MOVABLE; |
| |
| /* |
| * if the memory to be online is in a zone of 0...zone_last, and |
| * the zones of 0...zone_last don't have memory before online, we will |
| * need to set the node to node_states[N_NORMAL_MEMORY] after |
| * the memory is online. |
| */ |
| if (zone_idx(zone) <= zone_last && !node_state(nid, N_NORMAL_MEMORY)) |
| arg->status_change_nid_normal = nid; |
| else |
| arg->status_change_nid_normal = -1; |
| |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * If we have movable node, node_states[N_HIGH_MEMORY] |
| * contains nodes which have zones of 0...ZONE_HIGHMEM, |
| * set zone_last to ZONE_HIGHMEM. |
| * |
| * If we don't have movable node, node_states[N_NORMAL_MEMORY] |
| * contains nodes which have zones of 0...ZONE_MOVABLE, |
| * set zone_last to ZONE_MOVABLE. |
| */ |
| zone_last = ZONE_HIGHMEM; |
| if (N_MEMORY == N_HIGH_MEMORY) |
| zone_last = ZONE_MOVABLE; |
| |
| if (zone_idx(zone) <= zone_last && !node_state(nid, N_HIGH_MEMORY)) |
| arg->status_change_nid_high = nid; |
| else |
| arg->status_change_nid_high = -1; |
| #else |
| arg->status_change_nid_high = arg->status_change_nid_normal; |
| #endif |
| |
| /* |
| * if the node don't have memory befor online, we will need to |
| * set the node to node_states[N_MEMORY] after the memory |
| * is online. |
| */ |
| if (!node_state(nid, N_MEMORY)) |
| arg->status_change_nid = nid; |
| else |
| arg->status_change_nid = -1; |
| } |
| |
| static void node_states_set_node(int node, struct memory_notify *arg) |
| { |
| if (arg->status_change_nid_normal >= 0) |
| node_set_state(node, N_NORMAL_MEMORY); |
| |
| if (arg->status_change_nid_high >= 0) |
| node_set_state(node, N_HIGH_MEMORY); |
| |
| node_set_state(node, N_MEMORY); |
| } |
| |
| |
| int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_type) |
| { |
| unsigned long flags; |
| unsigned long onlined_pages = 0; |
| struct zone *zone; |
| int need_zonelists_rebuild = 0; |
| int nid; |
| int ret; |
| struct memory_notify arg; |
| |
| lock_memory_hotplug(); |
| /* |
| * This doesn't need a lock to do pfn_to_page(). |
| * The section can't be removed here because of the |
| * memory_block->state_mutex. |
| */ |
| zone = page_zone(pfn_to_page(pfn)); |
| |
| if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) && |
| !can_online_high_movable(zone)) { |
| unlock_memory_hotplug(); |
| return -EINVAL; |
| } |
| |
| if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) { |
| if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) { |
| unlock_memory_hotplug(); |
| return -EINVAL; |
| } |
| } |
| if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) { |
| if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) { |
| unlock_memory_hotplug(); |
| return -EINVAL; |
| } |
| } |
| |
| /* Previous code may changed the zone of the pfn range */ |
| zone = page_zone(pfn_to_page(pfn)); |
| |
| arg.start_pfn = pfn; |
| arg.nr_pages = nr_pages; |
| node_states_check_changes_online(nr_pages, zone, &arg); |
| |
| nid = pfn_to_nid(pfn); |
| |
| ret = memory_notify(MEM_GOING_ONLINE, &arg); |
| ret = notifier_to_errno(ret); |
| if (ret) { |
| memory_notify(MEM_CANCEL_ONLINE, &arg); |
| unlock_memory_hotplug(); |
| return ret; |
| } |
| /* |
| * If this zone is not populated, then it is not in zonelist. |
| * This means the page allocator ignores this zone. |
| * So, zonelist must be updated after online. |
| */ |
| mutex_lock(&zonelists_mutex); |
| if (!populated_zone(zone)) { |
| need_zonelists_rebuild = 1; |
| build_all_zonelists(NULL, zone); |
| } |
| |
| ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, |
| online_pages_range); |
| if (ret) { |
| if (need_zonelists_rebuild) |
| zone_pcp_reset(zone); |
| mutex_unlock(&zonelists_mutex); |
| printk(KERN_DEBUG "online_pages [mem %#010llx-%#010llx] failed\n", |
| (unsigned long long) pfn << PAGE_SHIFT, |
| (((unsigned long long) pfn + nr_pages) |
| << PAGE_SHIFT) - 1); |
| memory_notify(MEM_CANCEL_ONLINE, &arg); |
| unlock_memory_hotplug(); |
| return ret; |
| } |
| |
| zone->present_pages += onlined_pages; |
| |
| pgdat_resize_lock(zone->zone_pgdat, &flags); |
| zone->zone_pgdat->node_present_pages += onlined_pages; |
| pgdat_resize_unlock(zone->zone_pgdat, &flags); |
| |
| if (onlined_pages) { |
| node_states_set_node(zone_to_nid(zone), &arg); |
| if (need_zonelists_rebuild) |
| build_all_zonelists(NULL, NULL); |
| else |
| zone_pcp_update(zone); |
| } |
| |
| mutex_unlock(&zonelists_mutex); |
| |
| init_per_zone_wmark_min(); |
| |
| if (onlined_pages) |
| kswapd_run(zone_to_nid(zone)); |
| |
| vm_total_pages = nr_free_pagecache_pages(); |
| |
| writeback_set_ratelimit(); |
| |
| if (onlined_pages) |
| memory_notify(MEM_ONLINE, &arg); |
| unlock_memory_hotplug(); |
| |
| return 0; |
| } |
| #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ |
| |
| /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
| static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) |
| { |
| struct pglist_data *pgdat; |
| unsigned long zones_size[MAX_NR_ZONES] = {0}; |
| unsigned long zholes_size[MAX_NR_ZONES] = {0}; |
| unsigned long start_pfn = start >> PAGE_SHIFT; |
| |
| pgdat = NODE_DATA(nid); |
| if (!pgdat) { |
| pgdat = arch_alloc_nodedata(nid); |
| if (!pgdat) |
| return NULL; |
| |
| arch_refresh_nodedata(nid, pgdat); |
| } |
| |
| /* we can use NODE_DATA(nid) from here */ |
| |
| /* init node's zones as empty zones, we don't have any present pages.*/ |
| free_area_init_node(nid, zones_size, start_pfn, zholes_size); |
| |
| /* |
| * The node we allocated has no zone fallback lists. For avoiding |
| * to access not-initialized zonelist, build here. |
| */ |
| mutex_lock(&zonelists_mutex); |
| build_all_zonelists(pgdat, NULL); |
| mutex_unlock(&zonelists_mutex); |
| |
| return pgdat; |
| } |
| |
| static void rollback_node_hotadd(int nid, pg_data_t *pgdat) |
| { |
| arch_refresh_nodedata(nid, NULL); |
| arch_free_nodedata(pgdat); |
| return; |
| } |
| |
| |
| /** |
| * try_online_node - online a node if offlined |
| * |
| * called by cpu_up() to online a node without onlined memory. |
| */ |
| int try_online_node(int nid) |
| { |
| pg_data_t *pgdat; |
| int ret; |
| |
| if (node_online(nid)) |
| return 0; |
| |
| lock_memory_hotplug(); |
| pgdat = hotadd_new_pgdat(nid, 0); |
| if (!pgdat) { |
| pr_err("Cannot online node %d due to NULL pgdat\n", nid); |
| ret = -ENOMEM; |
| goto out; |
| } |
| node_set_online(nid); |
| ret = register_one_node(nid); |
| BUG_ON(ret); |
| |
| if (pgdat->node_zonelists->_zonerefs->zone == NULL) { |
| mutex_lock(&zonelists_mutex); |
| build_all_zonelists(NULL, NULL); |
| mutex_unlock(&zonelists_mutex); |
| } |
| |
| out: |
| unlock_memory_hotplug(); |
| return ret; |
| } |
| |
| static int check_hotplug_memory_range(u64 start, u64 size) |
| { |
| u64 start_pfn = start >> PAGE_SHIFT; |
| u64 nr_pages = size >> PAGE_SHIFT; |
| |
| /* Memory range must be aligned with section */ |
| if ((start_pfn & ~PAGE_SECTION_MASK) || |
| (nr_pages % PAGES_PER_SECTION) || (!nr_pages)) { |
| pr_err("Section-unaligned hotplug range: start 0x%llx, size 0x%llx\n", |
| (unsigned long long)start, |
| (unsigned long long)size); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ |
| int __ref add_memory(int nid, u64 start, u64 size) |
| { |
| pg_data_t *pgdat = NULL; |
| bool new_pgdat; |
| bool new_node; |
| struct resource *res; |
| int ret; |
| |
| ret = check_hotplug_memory_range(start, size); |
| if (ret) |
| return ret; |
| |
| lock_memory_hotplug(); |
| |
| res = register_memory_resource(start, size); |
| ret = -EEXIST; |
| if (!res) |
| goto out; |
| |
| { /* Stupid hack to suppress address-never-null warning */ |
| void *p = NODE_DATA(nid); |
| new_pgdat = !p; |
| } |
| new_node = !node_online(nid); |
| if (new_node) { |
| pgdat = hotadd_new_pgdat(nid, start); |
| ret = -ENOMEM; |
| if (!pgdat) |
| goto error; |
| } |
| |
| /* call arch's memory hotadd */ |
| ret = arch_add_memory(nid, start, size); |
| |
| if (ret < 0) |
| goto error; |
| |
| /* we online node here. we can't roll back from here. */ |
| node_set_online(nid); |
| |
| if (new_node) { |
| ret = register_one_node(nid); |
| /* |
| * If sysfs file of new node can't create, cpu on the node |
| * can't be hot-added. There is no rollback way now. |
| * So, check by BUG_ON() to catch it reluctantly.. |
| */ |
| BUG_ON(ret); |
| } |
| |
| /* create new memmap entry */ |
| firmware_map_add_hotplug(start, start + size, "System RAM"); |
| |
| goto out; |
| |
| error: |
| /* rollback pgdat allocation and others */ |
| if (new_pgdat) |
| rollback_node_hotadd(nid, pgdat); |
| release_memory_resource(res); |
| |
| out: |
| unlock_memory_hotplug(); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(add_memory); |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| /* |
| * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy |
| * set and the size of the free page is given by page_order(). Using this, |
| * the function determines if the pageblock contains only free pages. |
| * Due to buddy contraints, a free page at least the size of a pageblock will |
| * be located at the start of the pageblock |
| */ |
| static inline int pageblock_free(struct page *page) |
| { |
| return PageBuddy(page) && page_order(page) >= pageblock_order; |
| } |
| |
| /* Return the start of the next active pageblock after a given page */ |
| static struct page *next_active_pageblock(struct page *page) |
| { |
| /* Ensure the starting page is pageblock-aligned */ |
| BUG_ON(page_to_pfn(page) & (pageblock_nr_pages - 1)); |
| |
| /* If the entire pageblock is free, move to the end of free page */ |
| if (pageblock_free(page)) { |
| int order; |
| /* be careful. we don't have locks, page_order can be changed.*/ |
| order = page_order(page); |
| if ((order < MAX_ORDER) && (order >= pageblock_order)) |
| return page + (1 << order); |
| } |
| |
| return page + pageblock_nr_pages; |
| } |
| |
| /* Checks if this range of memory is likely to be hot-removable. */ |
| int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) |
| { |
| struct page *page = pfn_to_page(start_pfn); |
| struct page *end_page = page + nr_pages; |
| |
| /* Check the starting page of each pageblock within the range */ |
| for (; page < end_page; page = next_active_pageblock(page)) { |
| if (!is_pageblock_removable_nolock(page)) |
| return 0; |
| cond_resched(); |
| } |
| |
| /* All pageblocks in the memory block are likely to be hot-removable */ |
| return 1; |
| } |
| |
| /* |
| * Confirm all pages in a range [start, end) is belongs to the same zone. |
| */ |
| static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| struct zone *zone = NULL; |
| struct page *page; |
| int i; |
| for (pfn = start_pfn; |
| pfn < end_pfn; |
| pfn += MAX_ORDER_NR_PAGES) { |
| i = 0; |
| /* This is just a CONFIG_HOLES_IN_ZONE check.*/ |
| while ((i < MAX_ORDER_NR_PAGES) && !pfn_valid_within(pfn + i)) |
| i++; |
| if (i == MAX_ORDER_NR_PAGES) |
| continue; |
| page = pfn_to_page(pfn + i); |
| if (zone && page_zone(page) != zone) |
| return 0; |
| zone = page_zone(page); |
| } |
| return 1; |
| } |
| |
| /* |
| * Scan pfn range [start,end) to find movable/migratable pages (LRU pages |
| * and hugepages). We scan pfn because it's much easier than scanning over |
| * linked list. This function returns the pfn of the first found movable |
| * page if it's found, otherwise 0. |
| */ |
| static unsigned long scan_movable_pages(unsigned long start, unsigned long end) |
| { |
| unsigned long pfn; |
| struct page *page; |
| for (pfn = start; pfn < end; pfn++) { |
| if (pfn_valid(pfn)) { |
| page = pfn_to_page(pfn); |
| if (PageLRU(page)) |
| return pfn; |
| if (PageHuge(page)) { |
| if (is_hugepage_active(page)) |
| return pfn; |
| else |
| pfn = round_up(pfn + 1, |
| 1 << compound_order(page)) - 1; |
| } |
| } |
| } |
| return 0; |
| } |
| |
| #define NR_OFFLINE_AT_ONCE_PAGES (256) |
| static int |
| do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| struct page *page; |
| int move_pages = NR_OFFLINE_AT_ONCE_PAGES; |
| int not_managed = 0; |
| int ret = 0; |
| LIST_HEAD(source); |
| |
| for (pfn = start_pfn; pfn < end_pfn && move_pages > 0; pfn++) { |
| if (!pfn_valid(pfn)) |
| continue; |
| page = pfn_to_page(pfn); |
| |
| if (PageHuge(page)) { |
| struct page *head = compound_head(page); |
| pfn = page_to_pfn(head) + (1<<compound_order(head)) - 1; |
| if (compound_order(head) > PFN_SECTION_SHIFT) { |
| ret = -EBUSY; |
| break; |
| } |
| if (isolate_huge_page(page, &source)) |
| move_pages -= 1 << compound_order(head); |
| continue; |
| } |
| |
| if (!get_page_unless_zero(page)) |
| continue; |
| /* |
| * We can skip free pages. And we can only deal with pages on |
| * LRU. |
| */ |
| ret = isolate_lru_page(page); |
| if (!ret) { /* Success */ |
| put_page(page); |
| list_add_tail(&page->lru, &source); |
| move_pages--; |
| inc_zone_page_state(page, NR_ISOLATED_ANON + |
| page_is_file_cache(page)); |
| |
| } else { |
| #ifdef CONFIG_DEBUG_VM |
| printk(KERN_ALERT "removing pfn %lx from LRU failed\n", |
| pfn); |
| dump_page(page); |
| #endif |
| put_page(page); |
| /* Because we don't have big zone->lock. we should |
| check this again here. */ |
| if (page_count(page)) { |
| not_managed++; |
| ret = -EBUSY; |
| break; |
| } |
| } |
| } |
| if (!list_empty(&source)) { |
| if (not_managed) { |
| putback_movable_pages(&source); |
| goto out; |
| } |
| |
| /* |
| * alloc_migrate_target should be improooooved!! |
| * migrate_pages returns # of failed pages. |
| */ |
| ret = migrate_pages(&source, alloc_migrate_target, 0, |
| MIGRATE_SYNC, MR_MEMORY_HOTPLUG); |
| if (ret) |
| putback_movable_pages(&source); |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * remove from free_area[] and mark all as Reserved. |
| */ |
| static int |
| offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, |
| void *data) |
| { |
| __offline_isolated_pages(start, start + nr_pages); |
| return 0; |
| } |
| |
| static void |
| offline_isolated_pages(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| walk_system_ram_range(start_pfn, end_pfn - start_pfn, NULL, |
| offline_isolated_pages_cb); |
| } |
| |
| /* |
| * Check all pages in range, recoreded as memory resource, are isolated. |
| */ |
| static int |
| check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, |
| void *data) |
| { |
| int ret; |
| long offlined = *(long *)data; |
| ret = test_pages_isolated(start_pfn, start_pfn + nr_pages, true); |
| offlined = nr_pages; |
| if (!ret) |
| *(long *)data += offlined; |
| return ret; |
| } |
| |
| static long |
| check_pages_isolated(unsigned long start_pfn, unsigned long end_pfn) |
| { |
| long offlined = 0; |
| int ret; |
| |
| ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, &offlined, |
| check_pages_isolated_cb); |
| if (ret < 0) |
| offlined = (long)ret; |
| return offlined; |
| } |
| |
| #ifdef CONFIG_MOVABLE_NODE |
| /* |
| * When CONFIG_MOVABLE_NODE, we permit offlining of a node which doesn't have |
| * normal memory. |
| */ |
| static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) |
| { |
| return true; |
| } |
| #else /* CONFIG_MOVABLE_NODE */ |
| /* ensure the node has NORMAL memory if it is still online */ |
| static bool can_offline_normal(struct zone *zone, unsigned long nr_pages) |
| { |
| struct pglist_data *pgdat = zone->zone_pgdat; |
| unsigned long present_pages = 0; |
| enum zone_type zt; |
| |
| for (zt = 0; zt <= ZONE_NORMAL; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| |
| if (present_pages > nr_pages) |
| return true; |
| |
| present_pages = 0; |
| for (; zt <= ZONE_MOVABLE; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| |
| /* |
| * we can't offline the last normal memory until all |
| * higher memory is offlined. |
| */ |
| return present_pages == 0; |
| } |
| #endif /* CONFIG_MOVABLE_NODE */ |
| |
| static int __init cmdline_parse_movable_node(char *p) |
| { |
| #ifdef CONFIG_MOVABLE_NODE |
| /* |
| * Memory used by the kernel cannot be hot-removed because Linux |
| * cannot migrate the kernel pages. When memory hotplug is |
| * enabled, we should prevent memblock from allocating memory |
| * for the kernel. |
| * |
| * ACPI SRAT records all hotpluggable memory ranges. But before |
| * SRAT is parsed, we don't know about it. |
| * |
| * The kernel image is loaded into memory at very early time. We |
| * cannot prevent this anyway. So on NUMA system, we set any |
| * node the kernel resides in as un-hotpluggable. |
| * |
| * Since on modern servers, one node could have double-digit |
| * gigabytes memory, we can assume the memory around the kernel |
| * image is also un-hotpluggable. So before SRAT is parsed, just |
| * allocate memory near the kernel image to try the best to keep |
| * the kernel away from hotpluggable memory. |
| */ |
| memblock_set_bottom_up(true); |
| movable_node_enabled = true; |
| #else |
| pr_warn("movable_node option not supported\n"); |
| #endif |
| return 0; |
| } |
| early_param("movable_node", cmdline_parse_movable_node); |
| |
| /* check which state of node_states will be changed when offline memory */ |
| static void node_states_check_changes_offline(unsigned long nr_pages, |
| struct zone *zone, struct memory_notify *arg) |
| { |
| struct pglist_data *pgdat = zone->zone_pgdat; |
| unsigned long present_pages = 0; |
| enum zone_type zt, zone_last = ZONE_NORMAL; |
| |
| /* |
| * If we have HIGHMEM or movable node, node_states[N_NORMAL_MEMORY] |
| * contains nodes which have zones of 0...ZONE_NORMAL, |
| * set zone_last to ZONE_NORMAL. |
| * |
| * If we don't have HIGHMEM nor movable node, |
| * node_states[N_NORMAL_MEMORY] contains nodes which have zones of |
| * 0...ZONE_MOVABLE, set zone_last to ZONE_MOVABLE. |
| */ |
| if (N_MEMORY == N_NORMAL_MEMORY) |
| zone_last = ZONE_MOVABLE; |
| |
| /* |
| * check whether node_states[N_NORMAL_MEMORY] will be changed. |
| * If the memory to be offline is in a zone of 0...zone_last, |
| * and it is the last present memory, 0...zone_last will |
| * become empty after offline , thus we can determind we will |
| * need to clear the node from node_states[N_NORMAL_MEMORY]. |
| */ |
| for (zt = 0; zt <= zone_last; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) |
| arg->status_change_nid_normal = zone_to_nid(zone); |
| else |
| arg->status_change_nid_normal = -1; |
| |
| #ifdef CONFIG_HIGHMEM |
| /* |
| * If we have movable node, node_states[N_HIGH_MEMORY] |
| * contains nodes which have zones of 0...ZONE_HIGHMEM, |
| * set zone_last to ZONE_HIGHMEM. |
| * |
| * If we don't have movable node, node_states[N_NORMAL_MEMORY] |
| * contains nodes which have zones of 0...ZONE_MOVABLE, |
| * set zone_last to ZONE_MOVABLE. |
| */ |
| zone_last = ZONE_HIGHMEM; |
| if (N_MEMORY == N_HIGH_MEMORY) |
| zone_last = ZONE_MOVABLE; |
| |
| for (; zt <= zone_last; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| if (zone_idx(zone) <= zone_last && nr_pages >= present_pages) |
| arg->status_change_nid_high = zone_to_nid(zone); |
| else |
| arg->status_change_nid_high = -1; |
| #else |
| arg->status_change_nid_high = arg->status_change_nid_normal; |
| #endif |
| |
| /* |
| * node_states[N_HIGH_MEMORY] contains nodes which have 0...ZONE_MOVABLE |
| */ |
| zone_last = ZONE_MOVABLE; |
| |
| /* |
| * check whether node_states[N_HIGH_MEMORY] will be changed |
| * If we try to offline the last present @nr_pages from the node, |
| * we can determind we will need to clear the node from |
| * node_states[N_HIGH_MEMORY]. |
| */ |
| for (; zt <= zone_last; zt++) |
| present_pages += pgdat->node_zones[zt].present_pages; |
| if (nr_pages >= present_pages) |
| arg->status_change_nid = zone_to_nid(zone); |
| else |
| arg->status_change_nid = -1; |
| } |
| |
| static void node_states_clear_node(int node, struct memory_notify *arg) |
| { |
| if (arg->status_change_nid_normal >= 0) |
| node_clear_state(node, N_NORMAL_MEMORY); |
| |
| if ((N_MEMORY != N_NORMAL_MEMORY) && |
| (arg->status_change_nid_high >= 0)) |
| node_clear_state(node, N_HIGH_MEMORY); |
| |
| if ((N_MEMORY != N_HIGH_MEMORY) && |
| (arg->status_change_nid >= 0)) |
| node_clear_state(node, N_MEMORY); |
| } |
| |
| static int __ref __offline_pages(unsigned long start_pfn, |
| unsigned long end_pfn, unsigned long timeout) |
| { |
| unsigned long pfn, nr_pages, expire; |
| long offlined_pages; |
| int ret, drain, retry_max, node; |
| unsigned long flags; |
| struct zone *zone; |
| struct memory_notify arg; |
| |
| /* at least, alignment against pageblock is necessary */ |
| if (!IS_ALIGNED(start_pfn, pageblock_nr_pages)) |
| return -EINVAL; |
| if (!IS_ALIGNED(end_pfn, pageblock_nr_pages)) |
| return -EINVAL; |
| /* This makes hotplug much easier...and readable. |
| we assume this for now. .*/ |
| if (!test_pages_in_a_zone(start_pfn, end_pfn)) |
| return -EINVAL; |
| |
| lock_memory_hotplug(); |
| |
| zone = page_zone(pfn_to_page(start_pfn)); |
| node = zone_to_nid(zone); |
| nr_pages = end_pfn - start_pfn; |
| |
| ret = -EINVAL; |
| if (zone_idx(zone) <= ZONE_NORMAL && !can_offline_normal(zone, nr_pages)) |
| goto out; |
| |
| /* set above range as isolated */ |
| ret = start_isolate_page_range(start_pfn, end_pfn, |
| MIGRATE_MOVABLE, true); |
| if (ret) |
| goto out; |
| |
| arg.start_pfn = start_pfn; |
| arg.nr_pages = nr_pages; |
| node_states_check_changes_offline(nr_pages, zone, &arg); |
| |
| ret = memory_notify(MEM_GOING_OFFLINE, &arg); |
| ret = notifier_to_errno(ret); |
| if (ret) |
| goto failed_removal; |
| |
| pfn = start_pfn; |
| expire = jiffies + timeout; |
| drain = 0; |
| retry_max = 5; |
| repeat: |
| /* start memory hot removal */ |
| ret = -EAGAIN; |
| if (time_after(jiffies, expire)) |
| goto failed_removal; |
| ret = -EINTR; |
| if (signal_pending(current)) |
| goto failed_removal; |
| ret = 0; |
| if (drain) { |
| lru_add_drain_all(); |
| cond_resched(); |
| drain_all_pages(); |
| } |
| |
| pfn = scan_movable_pages(start_pfn, end_pfn); |
| if (pfn) { /* We have movable pages */ |
| ret = do_migrate_range(pfn, end_pfn); |
| if (!ret) { |
| drain = 1; |
| goto repeat; |
| } else { |
| if (ret < 0) |
| if (--retry_max == 0) |
| goto failed_removal; |
| yield(); |
| drain = 1; |
| goto repeat; |
| } |
| } |
| /* drain all zone's lru pagevec, this is asynchronous... */ |
| lru_add_drain_all(); |
| yield(); |
| /* drain pcp pages, this is synchronous. */ |
| drain_all_pages(); |
| /* |
| * dissolve free hugepages in the memory block before doing offlining |
| * actually in order to make hugetlbfs's object counting consistent. |
| */ |
| dissolve_free_huge_pages(start_pfn, end_pfn); |
| /* check again */ |
| offlined_pages = check_pages_isolated(start_pfn, end_pfn); |
| if (offlined_pages < 0) { |
| ret = -EBUSY; |
| goto failed_removal; |
| } |
| printk(KERN_INFO "Offlined Pages %ld\n", offlined_pages); |
| /* Ok, all of our target is isolated. |
| We cannot do rollback at this point. */ |
| offline_isolated_pages(start_pfn, end_pfn); |
| /* reset pagetype flags and makes migrate type to be MOVABLE */ |
| undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); |
| /* removal success */ |
| adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); |
| zone->present_pages -= offlined_pages; |
| |
| pgdat_resize_lock(zone->zone_pgdat, &flags); |
| zone->zone_pgdat->node_present_pages -= offlined_pages; |
| pgdat_resize_unlock(zone->zone_pgdat, &flags); |
| |
| init_per_zone_wmark_min(); |
| |
| if (!populated_zone(zone)) { |
| zone_pcp_reset(zone); |
| mutex_lock(&zonelists_mutex); |
| build_all_zonelists(NULL, NULL); |
| mutex_unlock(&zonelists_mutex); |
| } else |
| zone_pcp_update(zone); |
| |
| node_states_clear_node(node, &arg); |
| if (arg.status_change_nid >= 0) |
| kswapd_stop(node); |
| |
| vm_total_pages = nr_free_pagecache_pages(); |
| writeback_set_ratelimit(); |
| |
| memory_notify(MEM_OFFLINE, &arg); |
| unlock_memory_hotplug(); |
| return 0; |
| |
| failed_removal: |
| printk(KERN_INFO "memory offlining [mem %#010llx-%#010llx] failed\n", |
| (unsigned long long) start_pfn << PAGE_SHIFT, |
| ((unsigned long long) end_pfn << PAGE_SHIFT) - 1); |
| memory_notify(MEM_CANCEL_OFFLINE, &arg); |
| /* pushback to free area */ |
| undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); |
| |
| out: |
| unlock_memory_hotplug(); |
| return ret; |
| } |
| |
| int offline_pages(unsigned long start_pfn, unsigned long nr_pages) |
| { |
| return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ); |
| } |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |
| |
| /** |
| * walk_memory_range - walks through all mem sections in [start_pfn, end_pfn) |
| * @start_pfn: start pfn of the memory range |
| * @end_pfn: end pfn of the memory range |
| * @arg: argument passed to func |
| * @func: callback for each memory section walked |
| * |
| * This function walks through all present mem sections in range |
| * [start_pfn, end_pfn) and call func on each mem section. |
| * |
| * Returns the return value of func. |
| */ |
| int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn, |
| void *arg, int (*func)(struct memory_block *, void *)) |
| { |
| struct memory_block *mem = NULL; |
| struct mem_section *section; |
| unsigned long pfn, section_nr; |
| int ret; |
| |
| for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
| section_nr = pfn_to_section_nr(pfn); |
| if (!present_section_nr(section_nr)) |
| continue; |
| |
| section = __nr_to_section(section_nr); |
| /* same memblock? */ |
| if (mem) |
| if ((section_nr >= mem->start_section_nr) && |
| (section_nr <= mem->end_section_nr)) |
| continue; |
| |
| mem = find_memory_block_hinted(section, mem); |
| if (!mem) |
| continue; |
| |
| ret = func(mem, arg); |
| if (ret) { |
| kobject_put(&mem->dev.kobj); |
| return ret; |
| } |
| } |
| |
| if (mem) |
| kobject_put(&mem->dev.kobj); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_MEMORY_HOTREMOVE |
| static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) |
| { |
| int ret = !is_memblock_offlined(mem); |
| |
| if (unlikely(ret)) { |
| phys_addr_t beginpa, endpa; |
| |
| beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); |
| endpa = PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1; |
| pr_warn("removing memory fails, because memory " |
| "[%pa-%pa] is onlined\n", |
| &beginpa, &endpa); |
| } |
| |
| return ret; |
| } |
| |
| static int check_cpu_on_node(pg_data_t *pgdat) |
| { |
| int cpu; |
| |
| for_each_present_cpu(cpu) { |
| if (cpu_to_node(cpu) == pgdat->node_id) |
| /* |
| * the cpu on this node isn't removed, and we can't |
| * offline this node. |
| */ |
| return -EBUSY; |
| } |
| |
| return 0; |
| } |
| |
| static void unmap_cpu_on_node(pg_data_t *pgdat) |
| { |
| #ifdef CONFIG_ACPI_NUMA |
| int cpu; |
| |
| for_each_possible_cpu(cpu) |
| if (cpu_to_node(cpu) == pgdat->node_id) |
| numa_clear_node(cpu); |
| #endif |
| } |
| |
| static int check_and_unmap_cpu_on_node(pg_data_t *pgdat) |
| { |
| int ret; |
| |
| ret = check_cpu_on_node(pgdat); |
| if (ret) |
| return ret; |
| |
| /* |
| * the node will be offlined when we come here, so we can clear |
| * the cpu_to_node() now. |
| */ |
| |
| unmap_cpu_on_node(pgdat); |
| return 0; |
| } |
| |
| /** |
| * try_offline_node |
| * |
| * Offline a node if all memory sections and cpus of the node are removed. |
| * |
| * NOTE: The caller must call lock_device_hotplug() to serialize hotplug |
| * and online/offline operations before this call. |
| */ |
| void try_offline_node(int nid) |
| { |
| pg_data_t *pgdat = NODE_DATA(nid); |
| unsigned long start_pfn = pgdat->node_start_pfn; |
| unsigned long end_pfn = start_pfn + pgdat->node_spanned_pages; |
| unsigned long pfn; |
| struct page *pgdat_page = virt_to_page(pgdat); |
| int i; |
| |
| for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { |
| unsigned long section_nr = pfn_to_section_nr(pfn); |
| |
| if (!present_section_nr(section_nr)) |
| continue; |
| |
| if (pfn_to_nid(pfn) != nid) |
| continue; |
| |
| /* |
| * some memory sections of this node are not removed, and we |
| * can't offline node now. |
| */ |
| return; |
| } |
| |
| if (check_and_unmap_cpu_on_node(pgdat)) |
| return; |
| |
| /* |
| * all memory/cpu of this node are removed, we can offline this |
| * node now. |
| */ |
| node_set_offline(nid); |
| unregister_one_node(nid); |
| |
| if (!PageSlab(pgdat_page) && !PageCompound(pgdat_page)) |
| /* node data is allocated from boot memory */ |
| return; |
| |
| /* free waittable in each zone */ |
| for (i = 0; i < MAX_NR_ZONES; i++) { |
| struct zone *zone = pgdat->node_zones + i; |
| |
| /* |
| * wait_table may be allocated from boot memory, |
| * here only free if it's allocated by vmalloc. |
| */ |
| if (is_vmalloc_addr(zone->wait_table)) |
| vfree(zone->wait_table); |
| } |
| |
| /* |
| * Since there is no way to guarentee the address of pgdat/zone is not |
| * on stack of any kernel threads or used by other kernel objects |
| * without reference counting or other symchronizing method, do not |
| * reset node_data and free pgdat here. Just reset it to 0 and reuse |
| * the memory when the node is online again. |
| */ |
| memset(pgdat, 0, sizeof(*pgdat)); |
| } |
| EXPORT_SYMBOL(try_offline_node); |
| |
| /** |
| * remove_memory |
| * |
| * NOTE: The caller must call lock_device_hotplug() to serialize hotplug |
| * and online/offline operations before this call, as required by |
| * try_offline_node(). |
| */ |
| void __ref remove_memory(int nid, u64 start, u64 size) |
| { |
| int ret; |
| |
| BUG_ON(check_hotplug_memory_range(start, size)); |
| |
| lock_memory_hotplug(); |
| |
| /* |
| * All memory blocks must be offlined before removing memory. Check |
| * whether all memory blocks in question are offline and trigger a BUG() |
| * if this is not the case. |
| */ |
| ret = walk_memory_range(PFN_DOWN(start), PFN_UP(start + size - 1), NULL, |
| check_memblock_offlined_cb); |
| if (ret) { |
| unlock_memory_hotplug(); |
| BUG(); |
| } |
| |
| /* remove memmap entry */ |
| firmware_map_remove(start, start + size, "System RAM"); |
| |
| arch_remove_memory(start, size); |
| |
| try_offline_node(nid); |
| |
| unlock_memory_hotplug(); |
| } |
| EXPORT_SYMBOL_GPL(remove_memory); |
| #endif /* CONFIG_MEMORY_HOTREMOVE */ |