blob: f35abff8be60f8703d7e36bdd1c21aa94eaeff76 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* Generic hugetlb support.
* (C) Nadia Yvette Chambers, April 2004
*/
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/sysctl.h>
#include <linux/highmem.h>
#include <linux/mmu_notifier.h>
#include <linux/nodemask.h>
#include <linux/pagemap.h>
#include <linux/mempolicy.h>
#include <linux/compiler.h>
#include <linux/cpuset.h>
#include <linux/mutex.h>
#include <linux/memblock.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/sched/mm.h>
#include <linux/mmdebug.h>
#include <linux/sched/signal.h>
#include <linux/rmap.h>
#include <linux/string_helpers.h>
#include <linux/swap.h>
#include <linux/swapops.h>
#include <linux/jhash.h>
#include <linux/numa.h>
#include <linux/llist.h>
#include <linux/cma.h>
#include <linux/migrate.h>
#include <linux/nospec.h>
#include <linux/delayacct.h>
#include <linux/memory.h>
#include <linux/mm_inline.h>
#include <linux/padata.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <linux/io.h>
#include <linux/hugetlb.h>
#include <linux/hugetlb_cgroup.h>
#include <linux/node.h>
#include <linux/page_owner.h>
#include "internal.h"
#include "hugetlb_vmemmap.h"
int hugetlb_max_hstate __read_mostly;
unsigned int default_hstate_idx;
struct hstate hstates[HUGE_MAX_HSTATE];
#ifdef CONFIG_CMA
static struct cma *hugetlb_cma[MAX_NUMNODES];
static unsigned long hugetlb_cma_size_in_node[MAX_NUMNODES] __initdata;
static bool hugetlb_cma_folio(struct folio *folio, unsigned int order)
{
return cma_pages_valid(hugetlb_cma[folio_nid(folio)], &folio->page,
1 << order);
}
#else
static bool hugetlb_cma_folio(struct folio *folio, unsigned int order)
{
return false;
}
#endif
static unsigned long hugetlb_cma_size __initdata;
__initdata struct list_head huge_boot_pages[MAX_NUMNODES];
/* for command line parsing */
static struct hstate * __initdata parsed_hstate;
static unsigned long __initdata default_hstate_max_huge_pages;
static bool __initdata parsed_valid_hugepagesz = true;
static bool __initdata parsed_default_hugepagesz;
static unsigned int default_hugepages_in_node[MAX_NUMNODES] __initdata;
/*
* Protects updates to hugepage_freelists, hugepage_activelist, nr_huge_pages,
* free_huge_pages, and surplus_huge_pages.
*/
DEFINE_SPINLOCK(hugetlb_lock);
/*
* Serializes faults on the same logical page. This is used to
* prevent spurious OOMs when the hugepage pool is fully utilized.
*/
static int num_fault_mutexes;
struct mutex *hugetlb_fault_mutex_table ____cacheline_aligned_in_smp;
/* Forward declaration */
static int hugetlb_acct_memory(struct hstate *h, long delta);
static void hugetlb_vma_lock_free(struct vm_area_struct *vma);
static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma);
static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma);
static void hugetlb_unshare_pmds(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
static struct resv_map *vma_resv_map(struct vm_area_struct *vma);
static inline bool subpool_is_free(struct hugepage_subpool *spool)
{
if (spool->count)
return false;
if (spool->max_hpages != -1)
return spool->used_hpages == 0;
if (spool->min_hpages != -1)
return spool->rsv_hpages == spool->min_hpages;
return true;
}
static inline void unlock_or_release_subpool(struct hugepage_subpool *spool,
unsigned long irq_flags)
{
spin_unlock_irqrestore(&spool->lock, irq_flags);
/* If no pages are used, and no other handles to the subpool
* remain, give up any reservations based on minimum size and
* free the subpool */
if (subpool_is_free(spool)) {
if (spool->min_hpages != -1)
hugetlb_acct_memory(spool->hstate,
-spool->min_hpages);
kfree(spool);
}
}
struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
long min_hpages)
{
struct hugepage_subpool *spool;
spool = kzalloc(sizeof(*spool), GFP_KERNEL);
if (!spool)
return NULL;
spin_lock_init(&spool->lock);
spool->count = 1;
spool->max_hpages = max_hpages;
spool->hstate = h;
spool->min_hpages = min_hpages;
if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) {
kfree(spool);
return NULL;
}
spool->rsv_hpages = min_hpages;
return spool;
}
void hugepage_put_subpool(struct hugepage_subpool *spool)
{
unsigned long flags;
spin_lock_irqsave(&spool->lock, flags);
BUG_ON(!spool->count);
spool->count--;
unlock_or_release_subpool(spool, flags);
}
/*
* Subpool accounting for allocating and reserving pages.
* Return -ENOMEM if there are not enough resources to satisfy the
* request. Otherwise, return the number of pages by which the
* global pools must be adjusted (upward). The returned value may
* only be different than the passed value (delta) in the case where
* a subpool minimum size must be maintained.
*/
static long hugepage_subpool_get_pages(struct hugepage_subpool *spool,
long delta)
{
long ret = delta;
if (!spool)
return ret;
spin_lock_irq(&spool->lock);
if (spool->max_hpages != -1) { /* maximum size accounting */
if ((spool->used_hpages + delta) <= spool->max_hpages)
spool->used_hpages += delta;
else {
ret = -ENOMEM;
goto unlock_ret;
}
}
/* minimum size accounting */
if (spool->min_hpages != -1 && spool->rsv_hpages) {
if (delta > spool->rsv_hpages) {
/*
* Asking for more reserves than those already taken on
* behalf of subpool. Return difference.
*/
ret = delta - spool->rsv_hpages;
spool->rsv_hpages = 0;
} else {
ret = 0; /* reserves already accounted for */
spool->rsv_hpages -= delta;
}
}
unlock_ret:
spin_unlock_irq(&spool->lock);
return ret;
}
/*
* Subpool accounting for freeing and unreserving pages.
* Return the number of global page reservations that must be dropped.
* The return value may only be different than the passed value (delta)
* in the case where a subpool minimum size must be maintained.
*/
static long hugepage_subpool_put_pages(struct hugepage_subpool *spool,
long delta)
{
long ret = delta;
unsigned long flags;
if (!spool)
return delta;
spin_lock_irqsave(&spool->lock, flags);
if (spool->max_hpages != -1) /* maximum size accounting */
spool->used_hpages -= delta;
/* minimum size accounting */
if (spool->min_hpages != -1 && spool->used_hpages < spool->min_hpages) {
if (spool->rsv_hpages + delta <= spool->min_hpages)
ret = 0;
else
ret = spool->rsv_hpages + delta - spool->min_hpages;
spool->rsv_hpages += delta;
if (spool->rsv_hpages > spool->min_hpages)
spool->rsv_hpages = spool->min_hpages;
}
/*
* If hugetlbfs_put_super couldn't free spool due to an outstanding
* quota reference, free it now.
*/
unlock_or_release_subpool(spool, flags);
return ret;
}
static inline struct hugepage_subpool *subpool_inode(struct inode *inode)
{
return HUGETLBFS_SB(inode->i_sb)->spool;
}
static inline struct hugepage_subpool *subpool_vma(struct vm_area_struct *vma)
{
return subpool_inode(file_inode(vma->vm_file));
}
/*
* hugetlb vma_lock helper routines
*/
void hugetlb_vma_lock_read(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
down_read(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
down_read(&resv_map->rw_sema);
}
}
void hugetlb_vma_unlock_read(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
up_read(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
up_read(&resv_map->rw_sema);
}
}
void hugetlb_vma_lock_write(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
down_write(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
down_write(&resv_map->rw_sema);
}
}
void hugetlb_vma_unlock_write(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
up_write(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
up_write(&resv_map->rw_sema);
}
}
int hugetlb_vma_trylock_write(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
return down_write_trylock(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
return down_write_trylock(&resv_map->rw_sema);
}
return 1;
}
void hugetlb_vma_assert_locked(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
lockdep_assert_held(&vma_lock->rw_sema);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
lockdep_assert_held(&resv_map->rw_sema);
}
}
void hugetlb_vma_lock_release(struct kref *kref)
{
struct hugetlb_vma_lock *vma_lock = container_of(kref,
struct hugetlb_vma_lock, refs);
kfree(vma_lock);
}
static void __hugetlb_vma_unlock_write_put(struct hugetlb_vma_lock *vma_lock)
{
struct vm_area_struct *vma = vma_lock->vma;
/*
* vma_lock structure may or not be released as a result of put,
* it certainly will no longer be attached to vma so clear pointer.
* Semaphore synchronizes access to vma_lock->vma field.
*/
vma_lock->vma = NULL;
vma->vm_private_data = NULL;
up_write(&vma_lock->rw_sema);
kref_put(&vma_lock->refs, hugetlb_vma_lock_release);
}
static void __hugetlb_vma_unlock_write_free(struct vm_area_struct *vma)
{
if (__vma_shareable_lock(vma)) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
__hugetlb_vma_unlock_write_put(vma_lock);
} else if (__vma_private_lock(vma)) {
struct resv_map *resv_map = vma_resv_map(vma);
/* no free for anon vmas, but still need to unlock */
up_write(&resv_map->rw_sema);
}
}
static void hugetlb_vma_lock_free(struct vm_area_struct *vma)
{
/*
* Only present in sharable vmas.
*/
if (!vma || !__vma_shareable_lock(vma))
return;
if (vma->vm_private_data) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
down_write(&vma_lock->rw_sema);
__hugetlb_vma_unlock_write_put(vma_lock);
}
}
static void hugetlb_vma_lock_alloc(struct vm_area_struct *vma)
{
struct hugetlb_vma_lock *vma_lock;
/* Only establish in (flags) sharable vmas */
if (!vma || !(vma->vm_flags & VM_MAYSHARE))
return;
/* Should never get here with non-NULL vm_private_data */
if (vma->vm_private_data)
return;
vma_lock = kmalloc(sizeof(*vma_lock), GFP_KERNEL);
if (!vma_lock) {
/*
* If we can not allocate structure, then vma can not
* participate in pmd sharing. This is only a possible
* performance enhancement and memory saving issue.
* However, the lock is also used to synchronize page
* faults with truncation. If the lock is not present,
* unlikely races could leave pages in a file past i_size
* until the file is removed. Warn in the unlikely case of
* allocation failure.
*/
pr_warn_once("HugeTLB: unable to allocate vma specific lock\n");
return;
}
kref_init(&vma_lock->refs);
init_rwsem(&vma_lock->rw_sema);
vma_lock->vma = vma;
vma->vm_private_data = vma_lock;
}
/* Helper that removes a struct file_region from the resv_map cache and returns
* it for use.
*/
static struct file_region *
get_file_region_entry_from_cache(struct resv_map *resv, long from, long to)
{
struct file_region *nrg;
VM_BUG_ON(resv->region_cache_count <= 0);
resv->region_cache_count--;
nrg = list_first_entry(&resv->region_cache, struct file_region, link);
list_del(&nrg->link);
nrg->from = from;
nrg->to = to;
return nrg;
}
static void copy_hugetlb_cgroup_uncharge_info(struct file_region *nrg,
struct file_region *rg)
{
#ifdef CONFIG_CGROUP_HUGETLB
nrg->reservation_counter = rg->reservation_counter;
nrg->css = rg->css;
if (rg->css)
css_get(rg->css);
#endif
}
/* Helper that records hugetlb_cgroup uncharge info. */
static void record_hugetlb_cgroup_uncharge_info(struct hugetlb_cgroup *h_cg,
struct hstate *h,
struct resv_map *resv,
struct file_region *nrg)
{
#ifdef CONFIG_CGROUP_HUGETLB
if (h_cg) {
nrg->reservation_counter =
&h_cg->rsvd_hugepage[hstate_index(h)];
nrg->css = &h_cg->css;
/*
* The caller will hold exactly one h_cg->css reference for the
* whole contiguous reservation region. But this area might be
* scattered when there are already some file_regions reside in
* it. As a result, many file_regions may share only one css
* reference. In order to ensure that one file_region must hold
* exactly one h_cg->css reference, we should do css_get for
* each file_region and leave the reference held by caller
* untouched.
*/
css_get(&h_cg->css);
if (!resv->pages_per_hpage)
resv->pages_per_hpage = pages_per_huge_page(h);
/* pages_per_hpage should be the same for all entries in
* a resv_map.
*/
VM_BUG_ON(resv->pages_per_hpage != pages_per_huge_page(h));
} else {
nrg->reservation_counter = NULL;
nrg->css = NULL;
}
#endif
}
static void put_uncharge_info(struct file_region *rg)
{
#ifdef CONFIG_CGROUP_HUGETLB
if (rg->css)
css_put(rg->css);
#endif
}
static bool has_same_uncharge_info(struct file_region *rg,
struct file_region *org)
{
#ifdef CONFIG_CGROUP_HUGETLB
return rg->reservation_counter == org->reservation_counter &&
rg->css == org->css;
#else
return true;
#endif
}
static void coalesce_file_region(struct resv_map *resv, struct file_region *rg)
{
struct file_region *nrg, *prg;
prg = list_prev_entry(rg, link);
if (&prg->link != &resv->regions && prg->to == rg->from &&
has_same_uncharge_info(prg, rg)) {
prg->to = rg->to;
list_del(&rg->link);
put_uncharge_info(rg);
kfree(rg);
rg = prg;
}
nrg = list_next_entry(rg, link);
if (&nrg->link != &resv->regions && nrg->from == rg->to &&
has_same_uncharge_info(nrg, rg)) {
nrg->from = rg->from;
list_del(&rg->link);
put_uncharge_info(rg);
kfree(rg);
}
}
static inline long
hugetlb_resv_map_add(struct resv_map *map, struct list_head *rg, long from,
long to, struct hstate *h, struct hugetlb_cgroup *cg,
long *regions_needed)
{
struct file_region *nrg;
if (!regions_needed) {
nrg = get_file_region_entry_from_cache(map, from, to);
record_hugetlb_cgroup_uncharge_info(cg, h, map, nrg);
list_add(&nrg->link, rg);
coalesce_file_region(map, nrg);
} else
*regions_needed += 1;
return to - from;
}
/*
* Must be called with resv->lock held.
*
* Calling this with regions_needed != NULL will count the number of pages
* to be added but will not modify the linked list. And regions_needed will
* indicate the number of file_regions needed in the cache to carry out to add
* the regions for this range.
*/
static long add_reservation_in_range(struct resv_map *resv, long f, long t,
struct hugetlb_cgroup *h_cg,
struct hstate *h, long *regions_needed)
{
long add = 0;
struct list_head *head = &resv->regions;
long last_accounted_offset = f;
struct file_region *iter, *trg = NULL;
struct list_head *rg = NULL;
if (regions_needed)
*regions_needed = 0;
/* In this loop, we essentially handle an entry for the range
* [last_accounted_offset, iter->from), at every iteration, with some
* bounds checking.
*/
list_for_each_entry_safe(iter, trg, head, link) {
/* Skip irrelevant regions that start before our range. */
if (iter->from < f) {
/* If this region ends after the last accounted offset,
* then we need to update last_accounted_offset.
*/
if (iter->to > last_accounted_offset)
last_accounted_offset = iter->to;
continue;
}
/* When we find a region that starts beyond our range, we've
* finished.
*/
if (iter->from >= t) {
rg = iter->link.prev;
break;
}
/* Add an entry for last_accounted_offset -> iter->from, and
* update last_accounted_offset.
*/
if (iter->from > last_accounted_offset)
add += hugetlb_resv_map_add(resv, iter->link.prev,
last_accounted_offset,
iter->from, h, h_cg,
regions_needed);
last_accounted_offset = iter->to;
}
/* Handle the case where our range extends beyond
* last_accounted_offset.
*/
if (!rg)
rg = head->prev;
if (last_accounted_offset < t)
add += hugetlb_resv_map_add(resv, rg, last_accounted_offset,
t, h, h_cg, regions_needed);
return add;
}
/* Must be called with resv->lock acquired. Will drop lock to allocate entries.
*/
static int allocate_file_region_entries(struct resv_map *resv,
int regions_needed)
__must_hold(&resv->lock)
{
LIST_HEAD(allocated_regions);
int to_allocate = 0, i = 0;
struct file_region *trg = NULL, *rg = NULL;
VM_BUG_ON(regions_needed < 0);
/*
* Check for sufficient descriptors in the cache to accommodate
* the number of in progress add operations plus regions_needed.
*
* This is a while loop because when we drop the lock, some other call
* to region_add or region_del may have consumed some region_entries,
* so we keep looping here until we finally have enough entries for
* (adds_in_progress + regions_needed).
*/
while (resv->region_cache_count <
(resv->adds_in_progress + regions_needed)) {
to_allocate = resv->adds_in_progress + regions_needed -
resv->region_cache_count;
/* At this point, we should have enough entries in the cache
* for all the existing adds_in_progress. We should only be
* needing to allocate for regions_needed.
*/
VM_BUG_ON(resv->region_cache_count < resv->adds_in_progress);
spin_unlock(&resv->lock);
for (i = 0; i < to_allocate; i++) {
trg = kmalloc(sizeof(*trg), GFP_KERNEL);
if (!trg)
goto out_of_memory;
list_add(&trg->link, &allocated_regions);
}
spin_lock(&resv->lock);
list_splice(&allocated_regions, &resv->region_cache);
resv->region_cache_count += to_allocate;
}
return 0;
out_of_memory:
list_for_each_entry_safe(rg, trg, &allocated_regions, link) {
list_del(&rg->link);
kfree(rg);
}
return -ENOMEM;
}
/*
* Add the huge page range represented by [f, t) to the reserve
* map. Regions will be taken from the cache to fill in this range.
* Sufficient regions should exist in the cache due to the previous
* call to region_chg with the same range, but in some cases the cache will not
* have sufficient entries due to races with other code doing region_add or
* region_del. The extra needed entries will be allocated.
*
* regions_needed is the out value provided by a previous call to region_chg.
*
* Return the number of new huge pages added to the map. This number is greater
* than or equal to zero. If file_region entries needed to be allocated for
* this operation and we were not able to allocate, it returns -ENOMEM.
* region_add of regions of length 1 never allocate file_regions and cannot
* fail; region_chg will always allocate at least 1 entry and a region_add for
* 1 page will only require at most 1 entry.
*/
static long region_add(struct resv_map *resv, long f, long t,
long in_regions_needed, struct hstate *h,
struct hugetlb_cgroup *h_cg)
{
long add = 0, actual_regions_needed = 0;
spin_lock(&resv->lock);
retry:
/* Count how many regions are actually needed to execute this add. */
add_reservation_in_range(resv, f, t, NULL, NULL,
&actual_regions_needed);
/*
* Check for sufficient descriptors in the cache to accommodate
* this add operation. Note that actual_regions_needed may be greater
* than in_regions_needed, as the resv_map may have been modified since
* the region_chg call. In this case, we need to make sure that we
* allocate extra entries, such that we have enough for all the
* existing adds_in_progress, plus the excess needed for this
* operation.
*/
if (actual_regions_needed > in_regions_needed &&
resv->region_cache_count <
resv->adds_in_progress +
(actual_regions_needed - in_regions_needed)) {
/* region_add operation of range 1 should never need to
* allocate file_region entries.
*/
VM_BUG_ON(t - f <= 1);
if (allocate_file_region_entries(
resv, actual_regions_needed - in_regions_needed)) {
return -ENOMEM;
}
goto retry;
}
add = add_reservation_in_range(resv, f, t, h_cg, h, NULL);
resv->adds_in_progress -= in_regions_needed;
spin_unlock(&resv->lock);
return add;
}
/*
* Examine the existing reserve map and determine how many
* huge pages in the specified range [f, t) are NOT currently
* represented. This routine is called before a subsequent
* call to region_add that will actually modify the reserve
* map to add the specified range [f, t). region_chg does
* not change the number of huge pages represented by the
* map. A number of new file_region structures is added to the cache as a
* placeholder, for the subsequent region_add call to use. At least 1
* file_region structure is added.
*
* out_regions_needed is the number of regions added to the
* resv->adds_in_progress. This value needs to be provided to a follow up call
* to region_add or region_abort for proper accounting.
*
* Returns the number of huge pages that need to be added to the existing
* reservation map for the range [f, t). This number is greater or equal to
* zero. -ENOMEM is returned if a new file_region structure or cache entry
* is needed and can not be allocated.
*/
static long region_chg(struct resv_map *resv, long f, long t,
long *out_regions_needed)
{
long chg = 0;
spin_lock(&resv->lock);
/* Count how many hugepages in this range are NOT represented. */
chg = add_reservation_in_range(resv, f, t, NULL, NULL,
out_regions_needed);
if (*out_regions_needed == 0)
*out_regions_needed = 1;
if (allocate_file_region_entries(resv, *out_regions_needed))
return -ENOMEM;
resv->adds_in_progress += *out_regions_needed;
spin_unlock(&resv->lock);
return chg;
}
/*
* Abort the in progress add operation. The adds_in_progress field
* of the resv_map keeps track of the operations in progress between
* calls to region_chg and region_add. Operations are sometimes
* aborted after the call to region_chg. In such cases, region_abort
* is called to decrement the adds_in_progress counter. regions_needed
* is the value returned by the region_chg call, it is used to decrement
* the adds_in_progress counter.
*
* NOTE: The range arguments [f, t) are not needed or used in this
* routine. They are kept to make reading the calling code easier as
* arguments will match the associated region_chg call.
*/
static void region_abort(struct resv_map *resv, long f, long t,
long regions_needed)
{
spin_lock(&resv->lock);
VM_BUG_ON(!resv->region_cache_count);
resv->adds_in_progress -= regions_needed;
spin_unlock(&resv->lock);
}
/*
* Delete the specified range [f, t) from the reserve map. If the
* t parameter is LONG_MAX, this indicates that ALL regions after f
* should be deleted. Locate the regions which intersect [f, t)
* and either trim, delete or split the existing regions.
*
* Returns the number of huge pages deleted from the reserve map.
* In the normal case, the return value is zero or more. In the
* case where a region must be split, a new region descriptor must
* be allocated. If the allocation fails, -ENOMEM will be returned.
* NOTE: If the parameter t == LONG_MAX, then we will never split
* a region and possibly return -ENOMEM. Callers specifying
* t == LONG_MAX do not need to check for -ENOMEM error.
*/
static long region_del(struct resv_map *resv, long f, long t)
{
struct list_head *head = &resv->regions;
struct file_region *rg, *trg;
struct file_region *nrg = NULL;
long del = 0;
retry:
spin_lock(&resv->lock);
list_for_each_entry_safe(rg, trg, head, link) {
/*
* Skip regions before the range to be deleted. file_region
* ranges are normally of the form [from, to). However, there
* may be a "placeholder" entry in the map which is of the form
* (from, to) with from == to. Check for placeholder entries
* at the beginning of the range to be deleted.
*/
if (rg->to <= f && (rg->to != rg->from || rg->to != f))
continue;
if (rg->from >= t)
break;
if (f > rg->from && t < rg->to) { /* Must split region */
/*
* Check for an entry in the cache before dropping
* lock and attempting allocation.
*/
if (!nrg &&
resv->region_cache_count > resv->adds_in_progress) {
nrg = list_first_entry(&resv->region_cache,
struct file_region,
link);
list_del(&nrg->link);
resv->region_cache_count--;
}
if (!nrg) {
spin_unlock(&resv->lock);
nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
if (!nrg)
return -ENOMEM;
goto retry;
}
del += t - f;
hugetlb_cgroup_uncharge_file_region(
resv, rg, t - f, false);
/* New entry for end of split region */
nrg->from = t;
nrg->to = rg->to;
copy_hugetlb_cgroup_uncharge_info(nrg, rg);
INIT_LIST_HEAD(&nrg->link);
/* Original entry is trimmed */
rg->to = f;
list_add(&nrg->link, &rg->link);
nrg = NULL;
break;
}
if (f <= rg->from && t >= rg->to) { /* Remove entire region */
del += rg->to - rg->from;
hugetlb_cgroup_uncharge_file_region(resv, rg,
rg->to - rg->from, true);
list_del(&rg->link);
kfree(rg);
continue;
}
if (f <= rg->from) { /* Trim beginning of region */
hugetlb_cgroup_uncharge_file_region(resv, rg,
t - rg->from, false);
del += t - rg->from;
rg->from = t;
} else { /* Trim end of region */
hugetlb_cgroup_uncharge_file_region(resv, rg,
rg->to - f, false);
del += rg->to - f;
rg->to = f;
}
}
spin_unlock(&resv->lock);
kfree(nrg);
return del;
}
/*
* A rare out of memory error was encountered which prevented removal of
* the reserve map region for a page. The huge page itself was free'ed
* and removed from the page cache. This routine will adjust the subpool
* usage count, and the global reserve count if needed. By incrementing
* these counts, the reserve map entry which could not be deleted will
* appear as a "reserved" entry instead of simply dangling with incorrect
* counts.
*/
void hugetlb_fix_reserve_counts(struct inode *inode)
{
struct hugepage_subpool *spool = subpool_inode(inode);
long rsv_adjust;
bool reserved = false;
rsv_adjust = hugepage_subpool_get_pages(spool, 1);
if (rsv_adjust > 0) {
struct hstate *h = hstate_inode(inode);
if (!hugetlb_acct_memory(h, 1))
reserved = true;
} else if (!rsv_adjust) {
reserved = true;
}
if (!reserved)
pr_warn("hugetlb: Huge Page Reserved count may go negative.\n");
}
/*
* Count and return the number of huge pages in the reserve map
* that intersect with the range [f, t).
*/
static long region_count(struct resv_map *resv, long f, long t)
{
struct list_head *head = &resv->regions;
struct file_region *rg;
long chg = 0;
spin_lock(&resv->lock);
/* Locate each segment we overlap with, and count that overlap. */
list_for_each_entry(rg, head, link) {
long seg_from;
long seg_to;
if (rg->to <= f)
continue;
if (rg->from >= t)
break;
seg_from = max(rg->from, f);
seg_to = min(rg->to, t);
chg += seg_to - seg_from;
}
spin_unlock(&resv->lock);
return chg;
}
/*
* Convert the address within this vma to the page offset within
* the mapping, huge page units here.
*/
static pgoff_t vma_hugecache_offset(struct hstate *h,
struct vm_area_struct *vma, unsigned long address)
{
return ((address - vma->vm_start) >> huge_page_shift(h)) +
(vma->vm_pgoff >> huge_page_order(h));
}
/**
* vma_kernel_pagesize - Page size granularity for this VMA.
* @vma: The user mapping.
*
* Folios in this VMA will be aligned to, and at least the size of the
* number of bytes returned by this function.
*
* Return: The default size of the folios allocated when backing a VMA.
*/
unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
{
if (vma->vm_ops && vma->vm_ops->pagesize)
return vma->vm_ops->pagesize(vma);
return PAGE_SIZE;
}
EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
/*
* Return the page size being used by the MMU to back a VMA. In the majority
* of cases, the page size used by the kernel matches the MMU size. On
* architectures where it differs, an architecture-specific 'strong'
* version of this symbol is required.
*/
__weak unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
{
return vma_kernel_pagesize(vma);
}
/*
* Flags for MAP_PRIVATE reservations. These are stored in the bottom
* bits of the reservation map pointer, which are always clear due to
* alignment.
*/
#define HPAGE_RESV_OWNER (1UL << 0)
#define HPAGE_RESV_UNMAPPED (1UL << 1)
#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
/*
* These helpers are used to track how many pages are reserved for
* faults in a MAP_PRIVATE mapping. Only the process that called mmap()
* is guaranteed to have their future faults succeed.
*
* With the exception of hugetlb_dup_vma_private() which is called at fork(),
* the reserve counters are updated with the hugetlb_lock held. It is safe
* to reset the VMA at fork() time as it is not in use yet and there is no
* chance of the global counters getting corrupted as a result of the values.
*
* The private mapping reservation is represented in a subtly different
* manner to a shared mapping. A shared mapping has a region map associated
* with the underlying file, this region map represents the backing file
* pages which have ever had a reservation assigned which this persists even
* after the page is instantiated. A private mapping has a region map
* associated with the original mmap which is attached to all VMAs which
* reference it, this region map represents those offsets which have consumed
* reservation ie. where pages have been instantiated.
*/
static unsigned long get_vma_private_data(struct vm_area_struct *vma)
{
return (unsigned long)vma->vm_private_data;
}
static void set_vma_private_data(struct vm_area_struct *vma,
unsigned long value)
{
vma->vm_private_data = (void *)value;
}
static void
resv_map_set_hugetlb_cgroup_uncharge_info(struct resv_map *resv_map,
struct hugetlb_cgroup *h_cg,
struct hstate *h)
{
#ifdef CONFIG_CGROUP_HUGETLB
if (!h_cg || !h) {
resv_map->reservation_counter = NULL;
resv_map->pages_per_hpage = 0;
resv_map->css = NULL;
} else {
resv_map->reservation_counter =
&h_cg->rsvd_hugepage[hstate_index(h)];
resv_map->pages_per_hpage = pages_per_huge_page(h);
resv_map->css = &h_cg->css;
}
#endif
}
struct resv_map *resv_map_alloc(void)
{
struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
struct file_region *rg = kmalloc(sizeof(*rg), GFP_KERNEL);
if (!resv_map || !rg) {
kfree(resv_map);
kfree(rg);
return NULL;
}
kref_init(&resv_map->refs);
spin_lock_init(&resv_map->lock);
INIT_LIST_HEAD(&resv_map->regions);
init_rwsem(&resv_map->rw_sema);
resv_map->adds_in_progress = 0;
/*
* Initialize these to 0. On shared mappings, 0's here indicate these
* fields don't do cgroup accounting. On private mappings, these will be
* re-initialized to the proper values, to indicate that hugetlb cgroup
* reservations are to be un-charged from here.
*/
resv_map_set_hugetlb_cgroup_uncharge_info(resv_map, NULL, NULL);
INIT_LIST_HEAD(&resv_map->region_cache);
list_add(&rg->link, &resv_map->region_cache);
resv_map->region_cache_count = 1;
return resv_map;
}
void resv_map_release(struct kref *ref)
{
struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
struct list_head *head = &resv_map->region_cache;
struct file_region *rg, *trg;
/* Clear out any active regions before we release the map. */
region_del(resv_map, 0, LONG_MAX);
/* ... and any entries left in the cache */
list_for_each_entry_safe(rg, trg, head, link) {
list_del(&rg->link);
kfree(rg);
}
VM_BUG_ON(resv_map->adds_in_progress);
kfree(resv_map);
}
static inline struct resv_map *inode_resv_map(struct inode *inode)
{
/*
* At inode evict time, i_mapping may not point to the original
* address space within the inode. This original address space
* contains the pointer to the resv_map. So, always use the
* address space embedded within the inode.
* The VERY common case is inode->mapping == &inode->i_data but,
* this may not be true for device special inodes.
*/
return (struct resv_map *)(&inode->i_data)->i_private_data;
}
static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
{
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
if (vma->vm_flags & VM_MAYSHARE) {
struct address_space *mapping = vma->vm_file->f_mapping;
struct inode *inode = mapping->host;
return inode_resv_map(inode);
} else {
return (struct resv_map *)(get_vma_private_data(vma) &
~HPAGE_RESV_MASK);
}
}
static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
{
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);
set_vma_private_data(vma, (unsigned long)map);
}
static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
{
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
VM_BUG_ON_VMA(vma->vm_flags & VM_MAYSHARE, vma);
set_vma_private_data(vma, get_vma_private_data(vma) | flags);
}
static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
{
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
return (get_vma_private_data(vma) & flag) != 0;
}
bool __vma_private_lock(struct vm_area_struct *vma)
{
return !(vma->vm_flags & VM_MAYSHARE) &&
get_vma_private_data(vma) & ~HPAGE_RESV_MASK &&
is_vma_resv_set(vma, HPAGE_RESV_OWNER);
}
void hugetlb_dup_vma_private(struct vm_area_struct *vma)
{
VM_BUG_ON_VMA(!is_vm_hugetlb_page(vma), vma);
/*
* Clear vm_private_data
* - For shared mappings this is a per-vma semaphore that may be
* allocated in a subsequent call to hugetlb_vm_op_open.
* Before clearing, make sure pointer is not associated with vma
* as this will leak the structure. This is the case when called
* via clear_vma_resv_huge_pages() and hugetlb_vm_op_open has already
* been called to allocate a new structure.
* - For MAP_PRIVATE mappings, this is the reserve map which does
* not apply to children. Faults generated by the children are
* not guaranteed to succeed, even if read-only.
*/
if (vma->vm_flags & VM_MAYSHARE) {
struct hugetlb_vma_lock *vma_lock = vma->vm_private_data;
if (vma_lock && vma_lock->vma != vma)
vma->vm_private_data = NULL;
} else
vma->vm_private_data = NULL;
}
/*
* Reset and decrement one ref on hugepage private reservation.
* Called with mm->mmap_lock writer semaphore held.
* This function should be only used by move_vma() and operate on
* same sized vma. It should never come here with last ref on the
* reservation.
*/
void clear_vma_resv_huge_pages(struct vm_area_struct *vma)
{
/*
* Clear the old hugetlb private page reservation.
* It has already been transferred to new_vma.
*
* During a mremap() operation of a hugetlb vma we call move_vma()
* which copies vma into new_vma and unmaps vma. After the copy
* operation both new_vma and vma share a reference to the resv_map
* struct, and at that point vma is about to be unmapped. We don't
* want to return the reservation to the pool at unmap of vma because
* the reservation still lives on in new_vma, so simply decrement the
* ref here and remove the resv_map reference from this vma.
*/
struct resv_map *reservations = vma_resv_map(vma);
if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
resv_map_put_hugetlb_cgroup_uncharge_info(reservations);
kref_put(&reservations->refs, resv_map_release);
}
hugetlb_dup_vma_private(vma);
}
/* Returns true if the VMA has associated reserve pages */
static bool vma_has_reserves(struct vm_area_struct *vma, long chg)
{
if (vma->vm_flags & VM_NORESERVE) {
/*
* This address is already reserved by other process(chg == 0),
* so, we should decrement reserved count. Without decrementing,
* reserve count remains after releasing inode, because this
* allocated page will go into page cache and is regarded as
* coming from reserved pool in releasing step. Currently, we
* don't have any other solution to deal with this situation
* properly, so add work-around here.
*/
if (vma->vm_flags & VM_MAYSHARE && chg == 0)
return true;
else
return false;
}
/* Shared mappings always use reserves */
if (vma->vm_flags & VM_MAYSHARE) {
/*
* We know VM_NORESERVE is not set. Therefore, there SHOULD
* be a region map for all pages. The only situation where
* there is no region map is if a hole was punched via
* fallocate. In this case, there really are no reserves to
* use. This situation is indicated if chg != 0.
*/
if (chg)
return false;
else
return true;
}
/*
* Only the process that called mmap() has reserves for
* private mappings.
*/
if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
/*
* Like the shared case above, a hole punch or truncate
* could have been performed on the private mapping.
* Examine the value of chg to determine if reserves
* actually exist or were previously consumed.
* Very Subtle - The value of chg comes from a previous
* call to vma_needs_reserves(). The reserve map for
* private mappings has different (opposite) semantics
* than that of shared mappings. vma_needs_reserves()
* has already taken this difference in semantics into
* account. Therefore, the meaning of chg is the same
* as in the shared case above. Code could easily be
* combined, but keeping it separate draws attention to
* subtle differences.
*/
if (chg)
return false;
else
return true;
}
return false;
}
static void enqueue_hugetlb_folio(struct hstate *h, struct folio *folio)
{
int nid = folio_nid(folio);
lockdep_assert_held(&hugetlb_lock);
VM_BUG_ON_FOLIO(folio_ref_count(folio), folio);
list_move(&folio->lru, &h->hugepage_freelists[nid]);
h->free_huge_pages++;
h->free_huge_pages_node[nid]++;
folio_set_hugetlb_freed(folio);
}
static struct folio *dequeue_hugetlb_folio_node_exact(struct hstate *h,
int nid)
{
struct folio *folio;
bool pin = !!(current->flags & PF_MEMALLOC_PIN);
lockdep_assert_held(&hugetlb_lock);
list_for_each_entry(folio, &h->hugepage_freelists[nid], lru) {
if (pin && !folio_is_longterm_pinnable(folio))
continue;
if (folio_test_hwpoison(folio))
continue;
list_move(&folio->lru, &h->hugepage_activelist);
folio_ref_unfreeze(folio, 1);
folio_clear_hugetlb_freed(folio);
h->free_huge_pages--;
h->free_huge_pages_node[nid]--;
return folio;
}
return NULL;
}
static struct folio *dequeue_hugetlb_folio_nodemask(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nmask)
{
unsigned int cpuset_mems_cookie;
struct zonelist *zonelist;
struct zone *zone;
struct zoneref *z;
int node = NUMA_NO_NODE;
zonelist = node_zonelist(nid, gfp_mask);
retry_cpuset:
cpuset_mems_cookie = read_mems_allowed_begin();
for_each_zone_zonelist_nodemask(zone, z, zonelist, gfp_zone(gfp_mask), nmask) {
struct folio *folio;
if (!cpuset_zone_allowed(zone, gfp_mask))
continue;
/*
* no need to ask again on the same node. Pool is node rather than
* zone aware
*/
if (zone_to_nid(zone) == node)
continue;
node = zone_to_nid(zone);
folio = dequeue_hugetlb_folio_node_exact(h, node);
if (folio)
return folio;
}
if (unlikely(read_mems_allowed_retry(cpuset_mems_cookie)))
goto retry_cpuset;
return NULL;
}
static unsigned long available_huge_pages(struct hstate *h)
{
return h->free_huge_pages - h->resv_huge_pages;
}
static struct folio *dequeue_hugetlb_folio_vma(struct hstate *h,
struct vm_area_struct *vma,
unsigned long address, int avoid_reserve,
long chg)
{
struct folio *folio = NULL;
struct mempolicy *mpol;
gfp_t gfp_mask;
nodemask_t *nodemask;
int nid;
/*
* A child process with MAP_PRIVATE mappings created by their parent
* have no page reserves. This check ensures that reservations are
* not "stolen". The child may still get SIGKILLed
*/
if (!vma_has_reserves(vma, chg) && !available_huge_pages(h))
goto err;
/* If reserves cannot be used, ensure enough pages are in the pool */
if (avoid_reserve && !available_huge_pages(h))
goto err;
gfp_mask = htlb_alloc_mask(h);
nid = huge_node(vma, address, gfp_mask, &mpol, &nodemask);
if (mpol_is_preferred_many(mpol)) {
folio = dequeue_hugetlb_folio_nodemask(h, gfp_mask,
nid, nodemask);
/* Fallback to all nodes if page==NULL */
nodemask = NULL;
}
if (!folio)
folio = dequeue_hugetlb_folio_nodemask(h, gfp_mask,
nid, nodemask);
if (folio && !avoid_reserve && vma_has_reserves(vma, chg)) {
folio_set_hugetlb_restore_reserve(folio);
h->resv_huge_pages--;
}
mpol_cond_put(mpol);
return folio;
err:
return NULL;
}
/*
* common helper functions for hstate_next_node_to_{alloc|free}.
* We may have allocated or freed a huge page based on a different
* nodes_allowed previously, so h->next_node_to_{alloc|free} might
* be outside of *nodes_allowed. Ensure that we use an allowed
* node for alloc or free.
*/
static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
{
nid = next_node_in(nid, *nodes_allowed);
VM_BUG_ON(nid >= MAX_NUMNODES);
return nid;
}
static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
{
if (!node_isset(nid, *nodes_allowed))
nid = next_node_allowed(nid, nodes_allowed);
return nid;
}
/*
* returns the previously saved node ["this node"] from which to
* allocate a persistent huge page for the pool and advance the
* next node from which to allocate, handling wrap at end of node
* mask.
*/
static int hstate_next_node_to_alloc(int *next_node,
nodemask_t *nodes_allowed)
{
int nid;
VM_BUG_ON(!nodes_allowed);
nid = get_valid_node_allowed(*next_node, nodes_allowed);
*next_node = next_node_allowed(nid, nodes_allowed);
return nid;
}
/*
* helper for remove_pool_hugetlb_folio() - return the previously saved
* node ["this node"] from which to free a huge page. Advance the
* next node id whether or not we find a free huge page to free so
* that the next attempt to free addresses the next node.
*/
static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
{
int nid;
VM_BUG_ON(!nodes_allowed);
nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
return nid;
}
#define for_each_node_mask_to_alloc(next_node, nr_nodes, node, mask) \
for (nr_nodes = nodes_weight(*mask); \
nr_nodes > 0 && \
((node = hstate_next_node_to_alloc(next_node, mask)) || 1); \
nr_nodes--)
#define for_each_node_mask_to_free(hs, nr_nodes, node, mask) \
for (nr_nodes = nodes_weight(*mask); \
nr_nodes > 0 && \
((node = hstate_next_node_to_free(hs, mask)) || 1); \
nr_nodes--)
/* used to demote non-gigantic_huge pages as well */
static void __destroy_compound_gigantic_folio(struct folio *folio,
unsigned int order, bool demote)
{
int i;
int nr_pages = 1 << order;
struct page *p;
atomic_set(&folio->_entire_mapcount, 0);
atomic_set(&folio->_large_mapcount, 0);
atomic_set(&folio->_pincount, 0);
for (i = 1; i < nr_pages; i++) {
p = folio_page(folio, i);
p->flags &= ~PAGE_FLAGS_CHECK_AT_FREE;
p->mapping = NULL;
clear_compound_head(p);
if (!demote)
set_page_refcounted(p);
}
__folio_clear_head(folio);
}
static void destroy_compound_hugetlb_folio_for_demote(struct folio *folio,
unsigned int order)
{
__destroy_compound_gigantic_folio(folio, order, true);
}
#ifdef CONFIG_ARCH_HAS_GIGANTIC_PAGE
static void destroy_compound_gigantic_folio(struct folio *folio,
unsigned int order)
{
__destroy_compound_gigantic_folio(folio, order, false);
}
static void free_gigantic_folio(struct folio *folio, unsigned int order)
{
/*
* If the page isn't allocated using the cma allocator,
* cma_release() returns false.
*/
#ifdef CONFIG_CMA
int nid = folio_nid(folio);
if (cma_release(hugetlb_cma[nid], &folio->page, 1 << order))
return;
#endif
free_contig_range(folio_pfn(folio), 1 << order);
}
#ifdef CONFIG_CONTIG_ALLOC
static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nodemask)
{
struct page *page;
unsigned long nr_pages = pages_per_huge_page(h);
if (nid == NUMA_NO_NODE)
nid = numa_mem_id();
#ifdef CONFIG_CMA
{
int node;
if (hugetlb_cma[nid]) {
page = cma_alloc(hugetlb_cma[nid], nr_pages,
huge_page_order(h), true);
if (page)
return page_folio(page);
}
if (!(gfp_mask & __GFP_THISNODE)) {
for_each_node_mask(node, *nodemask) {
if (node == nid || !hugetlb_cma[node])
continue;
page = cma_alloc(hugetlb_cma[node], nr_pages,
huge_page_order(h), true);
if (page)
return page_folio(page);
}
}
}
#endif
page = alloc_contig_pages(nr_pages, gfp_mask, nid, nodemask);
return page ? page_folio(page) : NULL;
}
#else /* !CONFIG_CONTIG_ALLOC */
static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nodemask)
{
return NULL;
}
#endif /* CONFIG_CONTIG_ALLOC */
#else /* !CONFIG_ARCH_HAS_GIGANTIC_PAGE */
static struct folio *alloc_gigantic_folio(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nodemask)
{
return NULL;
}
static inline void free_gigantic_folio(struct folio *folio,
unsigned int order) { }
static inline void destroy_compound_gigantic_folio(struct folio *folio,
unsigned int order) { }
#endif
/*
* Remove hugetlb folio from lists.
* If vmemmap exists for the folio, clear the hugetlb flag so that the
* folio appears as just a compound page. Otherwise, wait until after
* allocating vmemmap to clear the flag.
*
* A reference is held on the folio, except in the case of demote.
*
* Must be called with hugetlb lock held.
*/
static void __remove_hugetlb_folio(struct hstate *h, struct folio *folio,
bool adjust_surplus,
bool demote)
{
int nid = folio_nid(folio);
VM_BUG_ON_FOLIO(hugetlb_cgroup_from_folio(folio), folio);
VM_BUG_ON_FOLIO(hugetlb_cgroup_from_folio_rsvd(folio), folio);
lockdep_assert_held(&hugetlb_lock);
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
list_del(&folio->lru);
if (folio_test_hugetlb_freed(folio)) {
h->free_huge_pages--;
h->free_huge_pages_node[nid]--;
}
if (adjust_surplus) {
h->surplus_huge_pages--;
h->surplus_huge_pages_node[nid]--;
}
/*
* We can only clear the hugetlb flag after allocating vmemmap
* pages. Otherwise, someone (memory error handling) may try to write
* to tail struct pages.
*/
if (!folio_test_hugetlb_vmemmap_optimized(folio))
__folio_clear_hugetlb(folio);
/*
* In the case of demote we do not ref count the page as it will soon
* be turned into a page of smaller size.
*/
if (!demote)
folio_ref_unfreeze(folio, 1);
h->nr_huge_pages--;
h->nr_huge_pages_node[nid]--;
}
static void remove_hugetlb_folio(struct hstate *h, struct folio *folio,
bool adjust_surplus)
{
__remove_hugetlb_folio(h, folio, adjust_surplus, false);
}
static void remove_hugetlb_folio_for_demote(struct hstate *h, struct folio *folio,
bool adjust_surplus)
{
__remove_hugetlb_folio(h, folio, adjust_surplus, true);
}
static void add_hugetlb_folio(struct hstate *h, struct folio *folio,
bool adjust_surplus)
{
int zeroed;
int nid = folio_nid(folio);
VM_BUG_ON_FOLIO(!folio_test_hugetlb_vmemmap_optimized(folio), folio);
lockdep_assert_held(&hugetlb_lock);
INIT_LIST_HEAD(&folio->lru);
h->nr_huge_pages++;
h->nr_huge_pages_node[nid]++;
if (adjust_surplus) {
h->surplus_huge_pages++;
h->surplus_huge_pages_node[nid]++;
}
__folio_set_hugetlb(folio);
folio_change_private(folio, NULL);
/*
* We have to set hugetlb_vmemmap_optimized again as above
* folio_change_private(folio, NULL) cleared it.
*/
folio_set_hugetlb_vmemmap_optimized(folio);
/*
* This folio is about to be managed by the hugetlb allocator and
* should have no users. Drop our reference, and check for others
* just in case.
*/
zeroed = folio_put_testzero(folio);
if (unlikely(!zeroed))
/*
* It is VERY unlikely soneone else has taken a ref
* on the folio. In this case, we simply return as
* free_huge_folio() will be called when this other ref
* is dropped.
*/
return;
arch_clear_hugetlb_flags(folio);
enqueue_hugetlb_folio(h, folio);
}
static void __update_and_free_hugetlb_folio(struct hstate *h,
struct folio *folio)
{
bool clear_flag = folio_test_hugetlb_vmemmap_optimized(folio);
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
return;
/*
* If we don't know which subpages are hwpoisoned, we can't free
* the hugepage, so it's leaked intentionally.
*/
if (folio_test_hugetlb_raw_hwp_unreliable(folio))
return;
/*
* If folio is not vmemmap optimized (!clear_flag), then the folio
* is no longer identified as a hugetlb page. hugetlb_vmemmap_restore_folio
* can only be passed hugetlb pages and will BUG otherwise.
*/
if (clear_flag && hugetlb_vmemmap_restore_folio(h, folio)) {
spin_lock_irq(&hugetlb_lock);
/*
* If we cannot allocate vmemmap pages, just refuse to free the
* page and put the page back on the hugetlb free list and treat
* as a surplus page.
*/
add_hugetlb_folio(h, folio, true);
spin_unlock_irq(&hugetlb_lock);
return;
}
/*
* Move PageHWPoison flag from head page to the raw error pages,
* which makes any healthy subpages reusable.
*/
if (unlikely(folio_test_hwpoison(folio)))
folio_clear_hugetlb_hwpoison(folio);
/*
* If vmemmap pages were allocated above, then we need to clear the
* hugetlb flag under the hugetlb lock.
*/
if (folio_test_hugetlb(folio)) {
spin_lock_irq(&hugetlb_lock);
__folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
}
/*
* Non-gigantic pages demoted from CMA allocated gigantic pages
* need to be given back to CMA in free_gigantic_folio.
*/
if (hstate_is_gigantic(h) ||
hugetlb_cma_folio(folio, huge_page_order(h))) {
destroy_compound_gigantic_folio(folio, huge_page_order(h));
free_gigantic_folio(folio, huge_page_order(h));
} else {
INIT_LIST_HEAD(&folio->_deferred_list);
folio_put(folio);
}
}
/*
* As update_and_free_hugetlb_folio() can be called under any context, so we cannot
* use GFP_KERNEL to allocate vmemmap pages. However, we can defer the
* actual freeing in a workqueue to prevent from using GFP_ATOMIC to allocate
* the vmemmap pages.
*
* free_hpage_workfn() locklessly retrieves the linked list of pages to be
* freed and frees them one-by-one. As the page->mapping pointer is going
* to be cleared in free_hpage_workfn() anyway, it is reused as the llist_node
* structure of a lockless linked list of huge pages to be freed.
*/
static LLIST_HEAD(hpage_freelist);
static void free_hpage_workfn(struct work_struct *work)
{
struct llist_node *node;
node = llist_del_all(&hpage_freelist);
while (node) {
struct folio *folio;
struct hstate *h;
folio = container_of((struct address_space **)node,
struct folio, mapping);
node = node->next;
folio->mapping = NULL;
/*
* The VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio) in
* folio_hstate() is going to trigger because a previous call to
* remove_hugetlb_folio() will clear the hugetlb bit, so do
* not use folio_hstate() directly.
*/
h = size_to_hstate(folio_size(folio));
__update_and_free_hugetlb_folio(h, folio);
cond_resched();
}
}
static DECLARE_WORK(free_hpage_work, free_hpage_workfn);
static inline void flush_free_hpage_work(struct hstate *h)
{
if (hugetlb_vmemmap_optimizable(h))
flush_work(&free_hpage_work);
}
static void update_and_free_hugetlb_folio(struct hstate *h, struct folio *folio,
bool atomic)
{
if (!folio_test_hugetlb_vmemmap_optimized(folio) || !atomic) {
__update_and_free_hugetlb_folio(h, folio);
return;
}
/*
* Defer freeing to avoid using GFP_ATOMIC to allocate vmemmap pages.
*
* Only call schedule_work() if hpage_freelist is previously
* empty. Otherwise, schedule_work() had been called but the workfn
* hasn't retrieved the list yet.
*/
if (llist_add((struct llist_node *)&folio->mapping, &hpage_freelist))
schedule_work(&free_hpage_work);
}
static void bulk_vmemmap_restore_error(struct hstate *h,
struct list_head *folio_list,
struct list_head *non_hvo_folios)
{
struct folio *folio, *t_folio;
if (!list_empty(non_hvo_folios)) {
/*
* Free any restored hugetlb pages so that restore of the
* entire list can be retried.
* The idea is that in the common case of ENOMEM errors freeing
* hugetlb pages with vmemmap we will free up memory so that we
* can allocate vmemmap for more hugetlb pages.
*/
list_for_each_entry_safe(folio, t_folio, non_hvo_folios, lru) {
list_del(&folio->lru);
spin_lock_irq(&hugetlb_lock);
__folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
update_and_free_hugetlb_folio(h, folio, false);
cond_resched();
}
} else {
/*
* In the case where there are no folios which can be
* immediately freed, we loop through the list trying to restore
* vmemmap individually in the hope that someone elsewhere may
* have done something to cause success (such as freeing some
* memory). If unable to restore a hugetlb page, the hugetlb
* page is made a surplus page and removed from the list.
* If are able to restore vmemmap and free one hugetlb page, we
* quit processing the list to retry the bulk operation.
*/
list_for_each_entry_safe(folio, t_folio, folio_list, lru)
if (hugetlb_vmemmap_restore_folio(h, folio)) {
list_del(&folio->lru);
spin_lock_irq(&hugetlb_lock);
add_hugetlb_folio(h, folio, true);
spin_unlock_irq(&hugetlb_lock);
} else {
list_del(&folio->lru);
spin_lock_irq(&hugetlb_lock);
__folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
update_and_free_hugetlb_folio(h, folio, false);
cond_resched();
break;
}
}
}
static void update_and_free_pages_bulk(struct hstate *h,
struct list_head *folio_list)
{
long ret;
struct folio *folio, *t_folio;
LIST_HEAD(non_hvo_folios);
/*
* First allocate required vmemmmap (if necessary) for all folios.
* Carefully handle errors and free up any available hugetlb pages
* in an effort to make forward progress.
*/
retry:
ret = hugetlb_vmemmap_restore_folios(h, folio_list, &non_hvo_folios);
if (ret < 0) {
bulk_vmemmap_restore_error(h, folio_list, &non_hvo_folios);
goto retry;
}
/*
* At this point, list should be empty, ret should be >= 0 and there
* should only be pages on the non_hvo_folios list.
* Do note that the non_hvo_folios list could be empty.
* Without HVO enabled, ret will be 0 and there is no need to call
* __folio_clear_hugetlb as this was done previously.
*/
VM_WARN_ON(!list_empty(folio_list));
VM_WARN_ON(ret < 0);
if (!list_empty(&non_hvo_folios) && ret) {
spin_lock_irq(&hugetlb_lock);
list_for_each_entry(folio, &non_hvo_folios, lru)
__folio_clear_hugetlb(folio);
spin_unlock_irq(&hugetlb_lock);
}
list_for_each_entry_safe(folio, t_folio, &non_hvo_folios, lru) {
update_and_free_hugetlb_folio(h, folio, false);
cond_resched();
}
}
struct hstate *size_to_hstate(unsigned long size)
{
struct hstate *h;
for_each_hstate(h) {
if (huge_page_size(h) == size)
return h;
}
return NULL;
}
void free_huge_folio(struct folio *folio)
{
/*
* Can't pass hstate in here because it is called from the
* generic mm code.
*/
struct hstate *h = folio_hstate(folio);
int nid = folio_nid(folio);
struct hugepage_subpool *spool = hugetlb_folio_subpool(folio);
bool restore_reserve;
unsigned long flags;
VM_BUG_ON_FOLIO(folio_ref_count(folio), folio);
VM_BUG_ON_FOLIO(folio_mapcount(folio), folio);
hugetlb_set_folio_subpool(folio, NULL);
if (folio_test_anon(folio))
__ClearPageAnonExclusive(&folio->page);
folio->mapping = NULL;
restore_reserve = folio_test_hugetlb_restore_reserve(folio);
folio_clear_hugetlb_restore_reserve(folio);
/*
* If HPageRestoreReserve was set on page, page allocation consumed a
* reservation. If the page was associated with a subpool, there
* would have been a page reserved in the subpool before allocation
* via hugepage_subpool_get_pages(). Since we are 'restoring' the
* reservation, do not call hugepage_subpool_put_pages() as this will
* remove the reserved page from the subpool.
*/
if (!restore_reserve) {
/*
* A return code of zero implies that the subpool will be
* under its minimum size if the reservation is not restored
* after page is free. Therefore, force restore_reserve
* operation.
*/
if (hugepage_subpool_put_pages(spool, 1) == 0)
restore_reserve = true;
}
spin_lock_irqsave(&hugetlb_lock, flags);
folio_clear_hugetlb_migratable(folio);
hugetlb_cgroup_uncharge_folio(hstate_index(h),
pages_per_huge_page(h), folio);
hugetlb_cgroup_uncharge_folio_rsvd(hstate_index(h),
pages_per_huge_page(h), folio);
mem_cgroup_uncharge(folio);
if (restore_reserve)
h->resv_huge_pages++;
if (folio_test_hugetlb_temporary(folio)) {
remove_hugetlb_folio(h, folio, false);
spin_unlock_irqrestore(&hugetlb_lock, flags);
update_and_free_hugetlb_folio(h, folio, true);
} else if (h->surplus_huge_pages_node[nid]) {
/* remove the page from active list */
remove_hugetlb_folio(h, folio, true);
spin_unlock_irqrestore(&hugetlb_lock, flags);
update_and_free_hugetlb_folio(h, folio, true);
} else {
arch_clear_hugetlb_flags(folio);
enqueue_hugetlb_folio(h, folio);
spin_unlock_irqrestore(&hugetlb_lock, flags);
}
}
/*
* Must be called with the hugetlb lock held
*/
static void __prep_account_new_huge_page(struct hstate *h, int nid)
{
lockdep_assert_held(&hugetlb_lock);
h->nr_huge_pages++;
h->nr_huge_pages_node[nid]++;
}
static void init_new_hugetlb_folio(struct hstate *h, struct folio *folio)
{
__folio_set_hugetlb(folio);
INIT_LIST_HEAD(&folio->lru);
hugetlb_set_folio_subpool(folio, NULL);
set_hugetlb_cgroup(folio, NULL);
set_hugetlb_cgroup_rsvd(folio, NULL);
}
static void __prep_new_hugetlb_folio(struct hstate *h, struct folio *folio)
{
init_new_hugetlb_folio(h, folio);
hugetlb_vmemmap_optimize_folio(h, folio);
}
static void prep_new_hugetlb_folio(struct hstate *h, struct folio *folio, int nid)
{
__prep_new_hugetlb_folio(h, folio);
spin_lock_irq(&hugetlb_lock);
__prep_account_new_huge_page(h, nid);
spin_unlock_irq(&hugetlb_lock);
}
static bool __prep_compound_gigantic_folio(struct folio *folio,
unsigned int order, bool demote)
{
int i, j;
int nr_pages = 1 << order;
struct page *p;
__folio_clear_reserved(folio);
for (i = 0; i < nr_pages; i++) {
p = folio_page(folio, i);
/*
* For gigantic hugepages allocated through bootmem at
* boot, it's safer to be consistent with the not-gigantic
* hugepages and clear the PG_reserved bit from all tail pages
* too. Otherwise drivers using get_user_pages() to access tail
* pages may get the reference counting wrong if they see
* PG_reserved set on a tail page (despite the head page not
* having PG_reserved set). Enforcing this consistency between
* head and tail pages allows drivers to optimize away a check
* on the head page when they need know if put_page() is needed
* after get_user_pages().
*/
if (i != 0) /* head page cleared above */
__ClearPageReserved(p);
/*
* Subtle and very unlikely
*
* Gigantic 'page allocators' such as memblock or cma will
* return a set of pages with each page ref counted. We need
* to turn this set of pages into a compound page with tail
* page ref counts set to zero. Code such as speculative page
* cache adding could take a ref on a 'to be' tail page.
* We need to respect any increased ref count, and only set
* the ref count to zero if count is currently 1. If count
* is not 1, we return an error. An error return indicates
* the set of pages can not be converted to a gigantic page.
* The caller who allocated the pages should then discard the
* pages using the appropriate free interface.
*
* In the case of demote, the ref count will be zero.
*/
if (!demote) {
if (!page_ref_freeze(p, 1)) {
pr_warn("HugeTLB page can not be used due to unexpected inflated ref count\n");
goto out_error;
}
} else {
VM_BUG_ON_PAGE(page_count(p), p);
}
if (i != 0)
set_compound_head(p, &folio->page);
}
__folio_set_head(folio);
/* we rely on prep_new_hugetlb_folio to set the hugetlb flag */
folio_set_order(folio, order);
atomic_set(&folio->_entire_mapcount, -1);
atomic_set(&folio->_large_mapcount, -1);
atomic_set(&folio->_pincount, 0);
return true;
out_error:
/* undo page modifications made above */
for (j = 0; j < i; j++) {
p = folio_page(folio, j);
if (j != 0)
clear_compound_head(p);
set_page_refcounted(p);
}
/* need to clear PG_reserved on remaining tail pages */
for (; j < nr_pages; j++) {
p = folio_page(folio, j);
__ClearPageReserved(p);
}
return false;
}
static bool prep_compound_gigantic_folio(struct folio *folio,
unsigned int order)
{
return __prep_compound_gigantic_folio(folio, order, false);
}
static bool prep_compound_gigantic_folio_for_demote(struct folio *folio,
unsigned int order)
{
return __prep_compound_gigantic_folio(folio, order, true);
}
/*
* Find and lock address space (mapping) in write mode.
*
* Upon entry, the folio is locked which means that folio_mapping() is
* stable. Due to locking order, we can only trylock_write. If we can
* not get the lock, simply return NULL to caller.
*/
struct address_space *hugetlb_folio_mapping_lock_write(struct folio *folio)
{
struct address_space *mapping = folio_mapping(folio);
if (!mapping)
return mapping;
if (i_mmap_trylock_write(mapping))
return mapping;
return NULL;
}
static struct folio *alloc_buddy_hugetlb_folio(struct hstate *h,
gfp_t gfp_mask, int nid, nodemask_t *nmask,
nodemask_t *node_alloc_noretry)
{
int order = huge_page_order(h);
struct folio *folio;
bool alloc_try_hard = true;
bool retry = true;
/*
* By default we always try hard to allocate the folio with
* __GFP_RETRY_MAYFAIL flag. However, if we are allocating folios in
* a loop (to adjust global huge page counts) and previous allocation
* failed, do not continue to try hard on the same node. Use the
* node_alloc_noretry bitmap to manage this state information.
*/
if (node_alloc_noretry && node_isset(nid, *node_alloc_noretry))
alloc_try_hard = false;
gfp_mask |= __GFP_COMP|__GFP_NOWARN;
if (alloc_try_hard)
gfp_mask |= __GFP_RETRY_MAYFAIL;
if (nid == NUMA_NO_NODE)
nid = numa_mem_id();
retry:
folio = __folio_alloc(gfp_mask, order, nid, nmask);
if (folio && !folio_ref_freeze(folio, 1)) {
folio_put(folio);
if (retry) { /* retry once */
retry = false;
goto retry;
}
/* WOW! twice in a row. */
pr_warn("HugeTLB unexpected inflated folio ref count\n");
folio = NULL;
}
/*
* If we did not specify __GFP_RETRY_MAYFAIL, but still got a
* folio this indicates an overall state change. Clear bit so
* that we resume normal 'try hard' allocations.
*/
if (node_alloc_noretry && folio && !alloc_try_hard)
node_clear(nid, *node_alloc_noretry);
/*
* If we tried hard to get a folio but failed, set bit so that
* subsequent attempts will not try as hard until there is an
* overall state change.
*/
if (node_alloc_noretry && !folio && alloc_try_hard)
node_set(nid, *node_alloc_noretry);
if (!folio) {
__count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
return NULL;
}
__count_vm_event(HTLB_BUDDY_PGALLOC);
return folio;
}
static struct folio *__alloc_fresh_hugetlb_folio(struct hstate *h,
gfp_t gfp_mask, int nid, nodemask_t *nmask,
nodemask_t *node_alloc_noretry)
{
struct folio *folio;
bool retry = false;
retry:
if (hstate_is_gigantic(h))
folio = alloc_gigantic_folio(h, gfp_mask, nid, nmask);
else
folio = alloc_buddy_hugetlb_folio(h, gfp_mask,
nid, nmask, node_alloc_noretry);
if (!folio)
return NULL;
if (hstate_is_gigantic(h)) {
if (!prep_compound_gigantic_folio(folio, huge_page_order(h))) {
/*
* Rare failure to convert pages to compound page.
* Free pages and try again - ONCE!
*/
free_gigantic_folio(folio, huge_page_order(h));
if (!retry) {
retry = true;
goto retry;
}
return NULL;
}
}
return folio;
}
static struct folio *only_alloc_fresh_hugetlb_folio(struct hstate *h,
gfp_t gfp_mask, int nid, nodemask_t *nmask,
nodemask_t *node_alloc_noretry)
{
struct folio *folio;
folio = __alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask,
node_alloc_noretry);
if (folio)
init_new_hugetlb_folio(h, folio);
return folio;
}
/*
* Common helper to allocate a fresh hugetlb page. All specific allocators
* should use this function to get new hugetlb pages
*
* Note that returned page is 'frozen': ref count of head page and all tail
* pages is zero.
*/
static struct folio *alloc_fresh_hugetlb_folio(struct hstate *h,
gfp_t gfp_mask, int nid, nodemask_t *nmask,
nodemask_t *node_alloc_noretry)
{
struct folio *folio;
folio = __alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask,
node_alloc_noretry);
if (!folio)
return NULL;
prep_new_hugetlb_folio(h, folio, folio_nid(folio));
return folio;
}
static void prep_and_add_allocated_folios(struct hstate *h,
struct list_head *folio_list)
{
unsigned long flags;
struct folio *folio, *tmp_f;
/* Send list for bulk vmemmap optimization processing */
hugetlb_vmemmap_optimize_folios(h, folio_list);
/* Add all new pool pages to free lists in one lock cycle */
spin_lock_irqsave(&hugetlb_lock, flags);
list_for_each_entry_safe(folio, tmp_f, folio_list, lru) {
__prep_account_new_huge_page(h, folio_nid(folio));
enqueue_hugetlb_folio(h, folio);
}
spin_unlock_irqrestore(&hugetlb_lock, flags);
}
/*
* Allocates a fresh hugetlb page in a node interleaved manner. The page
* will later be added to the appropriate hugetlb pool.
*/
static struct folio *alloc_pool_huge_folio(struct hstate *h,
nodemask_t *nodes_allowed,
nodemask_t *node_alloc_noretry,
int *next_node)
{
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
int nr_nodes, node;
for_each_node_mask_to_alloc(next_node, nr_nodes, node, nodes_allowed) {
struct folio *folio;
folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, node,
nodes_allowed, node_alloc_noretry);
if (folio)
return folio;
}
return NULL;
}
/*
* Remove huge page from pool from next node to free. Attempt to keep
* persistent huge pages more or less balanced over allowed nodes.
* This routine only 'removes' the hugetlb page. The caller must make
* an additional call to free the page to low level allocators.
* Called with hugetlb_lock locked.
*/
static struct folio *remove_pool_hugetlb_folio(struct hstate *h,
nodemask_t *nodes_allowed, bool acct_surplus)
{
int nr_nodes, node;
struct folio *folio = NULL;
lockdep_assert_held(&hugetlb_lock);
for_each_node_mask_to_free(h, nr_nodes, node, nodes_allowed) {
/*
* If we're returning unused surplus pages, only examine
* nodes with surplus pages.
*/
if ((!acct_surplus || h->surplus_huge_pages_node[node]) &&
!list_empty(&h->hugepage_freelists[node])) {
folio = list_entry(h->hugepage_freelists[node].next,
struct folio, lru);
remove_hugetlb_folio(h, folio, acct_surplus);
break;
}
}
return folio;
}
/*
* Dissolve a given free hugetlb folio into free buddy pages. This function
* does nothing for in-use hugetlb folios and non-hugetlb folios.
* This function returns values like below:
*
* -ENOMEM: failed to allocate vmemmap pages to free the freed hugepages
* when the system is under memory pressure and the feature of
* freeing unused vmemmap pages associated with each hugetlb page
* is enabled.
* -EBUSY: failed to dissolved free hugepages or the hugepage is in-use
* (allocated or reserved.)
* 0: successfully dissolved free hugepages or the page is not a
* hugepage (considered as already dissolved)
*/
int dissolve_free_hugetlb_folio(struct folio *folio)
{
int rc = -EBUSY;
retry:
/* Not to disrupt normal path by vainly holding hugetlb_lock */
if (!folio_test_hugetlb(folio))
return 0;
spin_lock_irq(&hugetlb_lock);
if (!folio_test_hugetlb(folio)) {
rc = 0;
goto out;
}
if (!folio_ref_count(folio)) {
struct hstate *h = folio_hstate(folio);
if (!available_huge_pages(h))
goto out;
/*
* We should make sure that the page is already on the free list
* when it is dissolved.
*/
if (unlikely(!folio_test_hugetlb_freed(folio))) {
spin_unlock_irq(&hugetlb_lock);
cond_resched();
/*
* Theoretically, we should return -EBUSY when we
* encounter this race. In fact, we have a chance
* to successfully dissolve the page if we do a
* retry. Because the race window is quite small.
* If we seize this opportunity, it is an optimization
* for increasing the success rate of dissolving page.
*/
goto retry;
}
remove_hugetlb_folio(h, folio, false);
h->max_huge_pages--;
spin_unlock_irq(&hugetlb_lock);
/*
* Normally update_and_free_hugtlb_folio will allocate required vmemmmap
* before freeing the page. update_and_free_hugtlb_folio will fail to
* free the page if it can not allocate required vmemmap. We
* need to adjust max_huge_pages if the page is not freed.
* Attempt to allocate vmemmmap here so that we can take
* appropriate action on failure.
*
* The folio_test_hugetlb check here is because
* remove_hugetlb_folio will clear hugetlb folio flag for
* non-vmemmap optimized hugetlb folios.
*/
if (folio_test_hugetlb(folio)) {
rc = hugetlb_vmemmap_restore_folio(h, folio);
if (rc) {
spin_lock_irq(&hugetlb_lock);
add_hugetlb_folio(h, folio, false);
h->max_huge_pages++;
goto out;
}
} else
rc = 0;
update_and_free_hugetlb_folio(h, folio, false);
return rc;
}
out:
spin_unlock_irq(&hugetlb_lock);
return rc;
}
/*
* Dissolve free hugepages in a given pfn range. Used by memory hotplug to
* make specified memory blocks removable from the system.
* Note that this will dissolve a free gigantic hugepage completely, if any
* part of it lies within the given range.
* Also note that if dissolve_free_hugetlb_folio() returns with an error, all
* free hugetlb folios that were dissolved before that error are lost.
*/
int dissolve_free_hugetlb_folios(unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long pfn;
struct folio *folio;
int rc = 0;
unsigned int order;
struct hstate *h;
if (!hugepages_supported())
return rc;
order = huge_page_order(&default_hstate);
for_each_hstate(h)
order = min(order, huge_page_order(h));
for (pfn = start_pfn; pfn < end_pfn; pfn += 1 << order) {
folio = pfn_folio(pfn);
rc = dissolve_free_hugetlb_folio(folio);
if (rc)
break;
}
return rc;
}
/*
* Allocates a fresh surplus page from the page allocator.
*/
static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h,
gfp_t gfp_mask, int nid, nodemask_t *nmask)
{
struct folio *folio = NULL;
if (hstate_is_gigantic(h))
return NULL;
spin_lock_irq(&hugetlb_lock);
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages)
goto out_unlock;
spin_unlock_irq(&hugetlb_lock);
folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL);
if (!folio)
return NULL;
spin_lock_irq(&hugetlb_lock);
/*
* We could have raced with the pool size change.
* Double check that and simply deallocate the new page
* if we would end up overcommiting the surpluses. Abuse
* temporary page to workaround the nasty free_huge_folio
* codeflow
*/
if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
folio_set_hugetlb_temporary(folio);
spin_unlock_irq(&hugetlb_lock);
free_huge_folio(folio);
return NULL;
}
h->surplus_huge_pages++;
h->surplus_huge_pages_node[folio_nid(folio)]++;
out_unlock:
spin_unlock_irq(&hugetlb_lock);
return folio;
}
static struct folio *alloc_migrate_hugetlb_folio(struct hstate *h, gfp_t gfp_mask,
int nid, nodemask_t *nmask)
{
struct folio *folio;
if (hstate_is_gigantic(h))
return NULL;
folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL);
if (!folio)
return NULL;
/* fresh huge pages are frozen */
folio_ref_unfreeze(folio, 1);
/*
* We do not account these pages as surplus because they are only
* temporary and will be released properly on the last reference
*/
folio_set_hugetlb_temporary(folio);
return folio;
}
/*
* Use the VMA's mpolicy to allocate a huge page from the buddy.
*/
static
struct folio *alloc_buddy_hugetlb_folio_with_mpol(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
struct folio *folio = NULL;
struct mempolicy *mpol;
gfp_t gfp_mask = htlb_alloc_mask(h);
int nid;
nodemask_t *nodemask;
nid = huge_node(vma, addr, gfp_mask, &mpol, &nodemask);
if (mpol_is_preferred_many(mpol)) {
gfp_t gfp = gfp_mask | __GFP_NOWARN;
gfp &= ~(__GFP_DIRECT_RECLAIM | __GFP_NOFAIL);
folio = alloc_surplus_hugetlb_folio(h, gfp, nid, nodemask);
/* Fallback to all nodes if page==NULL */
nodemask = NULL;
}
if (!folio)
folio = alloc_surplus_hugetlb_folio(h, gfp_mask, nid, nodemask);
mpol_cond_put(mpol);
return folio;
}
/* folio migration callback function */
struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
nodemask_t *nmask, gfp_t gfp_mask, bool allow_alloc_fallback)
{
spin_lock_irq(&hugetlb_lock);
if (available_huge_pages(h)) {
struct folio *folio;
folio = dequeue_hugetlb_folio_nodemask(h, gfp_mask,
preferred_nid, nmask);
if (folio) {
spin_unlock_irq(&hugetlb_lock);
return folio;
}
}
spin_unlock_irq(&hugetlb_lock);
/* We cannot fallback to other nodes, as we could break the per-node pool. */
if (!allow_alloc_fallback)
gfp_mask |= __GFP_THISNODE;
return alloc_migrate_hugetlb_folio(h, gfp_mask, preferred_nid, nmask);
}
/*
* Increase the hugetlb pool such that it can accommodate a reservation
* of size 'delta'.
*/
static int gather_surplus_pages(struct hstate *h, long delta)
__must_hold(&hugetlb_lock)
{
LIST_HEAD(surplus_list);
struct folio *folio, *tmp;
int ret;
long i;
long needed, allocated;
bool alloc_ok = true;
lockdep_assert_held(&hugetlb_lock);
needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
if (needed <= 0) {
h->resv_huge_pages += delta;
return 0;
}
allocated = 0;
ret = -ENOMEM;
retry:
spin_unlock_irq(&hugetlb_lock);
for (i = 0; i < needed; i++) {
folio = alloc_surplus_hugetlb_folio(h, htlb_alloc_mask(h),
NUMA_NO_NODE, NULL);
if (!folio) {
alloc_ok = false;
break;
}
list_add(&folio->lru, &surplus_list);
cond_resched();
}
allocated += i;
/*
* After retaking hugetlb_lock, we need to recalculate 'needed'
* because either resv_huge_pages or free_huge_pages may have changed.
*/
spin_lock_irq(&hugetlb_lock);
needed = (h->resv_huge_pages + delta) -
(h->free_huge_pages + allocated);
if (needed > 0) {
if (alloc_ok)
goto retry;
/*
* We were not able to allocate enough pages to
* satisfy the entire reservation so we free what
* we've allocated so far.
*/
goto free;
}
/*
* The surplus_list now contains _at_least_ the number of extra pages
* needed to accommodate the reservation. Add the appropriate number
* of pages to the hugetlb pool and free the extras back to the buddy
* allocator. Commit the entire reservation here to prevent another
* process from stealing the pages as they are added to the pool but
* before they are reserved.
*/
needed += allocated;
h->resv_huge_pages += delta;
ret = 0;
/* Free the needed pages to the hugetlb pool */
list_for_each_entry_safe(folio, tmp, &surplus_list, lru) {
if ((--needed) < 0)
break;
/* Add the page to the hugetlb allocator */
enqueue_hugetlb_folio(h, folio);
}
free:
spin_unlock_irq(&hugetlb_lock);
/*
* Free unnecessary surplus pages to the buddy allocator.
* Pages have no ref count, call free_huge_folio directly.
*/
list_for_each_entry_safe(folio, tmp, &surplus_list, lru)
free_huge_folio(folio);
spin_lock_irq(&hugetlb_lock);
return ret;
}
/*
* This routine has two main purposes:
* 1) Decrement the reservation count (resv_huge_pages) by the value passed
* in unused_resv_pages. This corresponds to the prior adjustments made
* to the associated reservation map.
* 2) Free any unused surplus pages that may have been allocated to satisfy
* the reservation. As many as unused_resv_pages may be freed.
*/
static void return_unused_surplus_pages(struct hstate *h,
unsigned long unused_resv_pages)
{
unsigned long nr_pages;
LIST_HEAD(page_list);
lockdep_assert_held(&hugetlb_lock);
/* Uncommit the reservation */
h->resv_huge_pages -= unused_resv_pages;
if (hstate_is_gigantic(h) && !gigantic_page_runtime_supported())
goto out;
/*
* Part (or even all) of the reservation could have been backed
* by pre-allocated pages. Only free surplus pages.
*/
nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
/*
* We want to release as many surplus pages as possible, spread
* evenly across all nodes with memory. Iterate across these nodes
* until we can no longer free unreserved surplus pages. This occurs
* when the nodes with surplus pages have no free pages.
* remove_pool_hugetlb_folio() will balance the freed pages across the
* on-line nodes with memory and will handle the hstate accounting.
*/
while (nr_pages--) {
struct folio *folio;
folio = remove_pool_hugetlb_folio(h, &node_states[N_MEMORY], 1);
if (!folio)
goto out;
list_add(&folio->lru, &page_list);
}
out:
spin_unlock_irq(&hugetlb_lock);
update_and_free_pages_bulk(h, &page_list);
spin_lock_irq(&hugetlb_lock);
}
/*
* vma_needs_reservation, vma_commit_reservation and vma_end_reservation
* are used by the huge page allocation routines to manage reservations.
*
* vma_needs_reservation is called to determine if the huge page at addr
* within the vma has an associated reservation. If a reservation is
* needed, the value 1 is returned. The caller is then responsible for
* managing the global reservation and subpool usage counts. After
* the huge page has been allocated, vma_commit_reservation is called
* to add the page to the reservation map. If the page allocation fails,
* the reservation must be ended instead of committed. vma_end_reservation
* is called in such cases.
*
* In the normal case, vma_commit_reservation returns the same value
* as the preceding vma_needs_reservation call. The only time this
* is not the case is if a reserve map was changed between calls. It
* is the responsibility of the caller to notice the difference and
* take appropriate action.
*
* vma_add_reservation is used in error paths where a reservation must
* be restored when a newly allocated huge page must be freed. It is
* to be called after calling vma_needs_reservation to determine if a
* reservation exists.
*
* vma_del_reservation is used in error paths where an entry in the reserve
* map was created during huge page allocation and must be removed. It is to
* be called after calling vma_needs_reservation to determine if a reservation
* exists.
*/
enum vma_resv_mode {
VMA_NEEDS_RESV,
VMA_COMMIT_RESV,
VMA_END_RESV,
VMA_ADD_RESV,
VMA_DEL_RESV,
};
static long __vma_reservation_common(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr,
enum vma_resv_mode mode)
{
struct resv_map *resv;
pgoff_t idx;
long ret;
long dummy_out_regions_needed;
resv = vma_resv_map(vma);
if (!resv)
return 1;
idx = vma_hugecache_offset(h, vma, addr);
switch (mode) {
case VMA_NEEDS_RESV:
ret = region_chg(resv, idx, idx + 1, &dummy_out_regions_needed);
/* We assume that vma_reservation_* routines always operate on
* 1 page, and that adding to resv map a 1 page entry can only
* ever require 1 region.
*/
VM_BUG_ON(dummy_out_regions_needed != 1);
break;
case VMA_COMMIT_RESV:
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
/* region_add calls of range 1 should never fail. */
VM_BUG_ON(ret < 0);
break;
case VMA_END_RESV:
region_abort(resv, idx, idx + 1, 1);
ret = 0;
break;
case VMA_ADD_RESV:
if (vma->vm_flags & VM_MAYSHARE) {
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
/* region_add calls of range 1 should never fail. */
VM_BUG_ON(ret < 0);
} else {
region_abort(resv, idx, idx + 1, 1);
ret = region_del(resv, idx, idx + 1);
}
break;
case VMA_DEL_RESV:
if (vma->vm_flags & VM_MAYSHARE) {
region_abort(resv, idx, idx + 1, 1);
ret = region_del(resv, idx, idx + 1);
} else {
ret = region_add(resv, idx, idx + 1, 1, NULL, NULL);
/* region_add calls of range 1 should never fail. */
VM_BUG_ON(ret < 0);
}
break;
default:
BUG();
}
if (vma->vm_flags & VM_MAYSHARE || mode == VMA_DEL_RESV)
return ret;
/*
* We know private mapping must have HPAGE_RESV_OWNER set.
*
* In most cases, reserves always exist for private mappings.
* However, a file associated with mapping could have been
* hole punched or truncated after reserves were consumed.
* As subsequent fault on such a range will not use reserves.
* Subtle - The reserve map for private mappings has the
* opposite meaning than that of shared mappings. If NO
* entry is in the reserve map, it means a reservation exists.
* If an entry exists in the reserve map, it means the
* reservation has already been consumed. As a result, the
* return value of this routine is the opposite of the
* value returned from reserve map manipulation routines above.
*/
if (ret > 0)
return 0;
if (ret == 0)
return 1;
return ret;
}
static long vma_needs_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
return __vma_reservation_common(h, vma, addr, VMA_NEEDS_RESV);
}
static long vma_commit_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
return __vma_reservation_common(h, vma, addr, VMA_COMMIT_RESV);
}
static void vma_end_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
(void)__vma_reservation_common(h, vma, addr, VMA_END_RESV);
}
static long vma_add_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
return __vma_reservation_common(h, vma, addr, VMA_ADD_RESV);
}
static long vma_del_reservation(struct hstate *h,
struct vm_area_struct *vma, unsigned long addr)
{
return __vma_reservation_common(h, vma, addr, VMA_DEL_RESV);
}
/*
* This routine is called to restore reservation information on error paths.
* It should ONLY be called for folios allocated via alloc_hugetlb_folio(),
* and the hugetlb mutex should remain held when calling this routine.
*
* It handles two specific cases:
* 1) A reservation was in place and the folio consumed the reservation.
* hugetlb_restore_reserve is set in the folio.
* 2) No reservation was in place for the page, so hugetlb_restore_reserve is
* not set. However, alloc_hugetlb_folio always updates the reserve map.
*
* In case 1, free_huge_folio later in the error path will increment the
* global reserve count. But, free_huge_folio does not have enough context
* to adjust the reservation map. This case deals primarily with private
* mappings. Adjust the reserve map here to be consistent with global
* reserve count adjustments to be made by free_huge_folio. Make sure the
* reserve map indicates there is a reservation present.
*
* In case 2, simply undo reserve map modifications done by alloc_hugetlb_folio.
*/
void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
unsigned long address, struct folio *folio)
{
long rc = vma_needs_reservation(h, vma, address);
if (folio_test_hugetlb_restore_reserve(folio)) {
if (unlikely(rc < 0))
/*
* Rare out of memory condition in reserve map
* manipulation. Clear hugetlb_restore_reserve so
* that global reserve count will not be incremented
* by free_huge_folio. This will make it appear
* as though the reservation for this folio was
* consumed. This may prevent the task from
* faulting in the folio at a later time. This
* is better than inconsistent global huge page
* accounting of reserve counts.
*/
folio_clear_hugetlb_restore_reserve(folio);
else if (rc)
(void)vma_add_reservation(h, vma, address);
else
vma_end_reservation(h, vma, address);
} else {
if (!rc) {
/*
* This indicates there is an entry in the reserve map
* not added by alloc_hugetlb_folio. We know it was added
* before the alloc_hugetlb_folio call, otherwise
* hugetlb_restore_reserve would be set on the folio.
* Remove the entry so that a subsequent allocation
* does not consume a reservation.
*/
rc = vma_del_reservation(h, vma, address);
if (rc < 0)
/*
* VERY rare out of memory condition. Since
* we can not delete the entry, set
* hugetlb_restore_reserve so that the reserve
* count will be incremented when the folio
* is freed. This reserve will be consumed
* on a subsequent allocation.
*/
folio_set_hugetlb_restore_reserve(folio);
} else if (rc < 0) {
/*
* Rare out of memory condition from
* vma_needs_reservation call. Memory allocation is
* only attempted if a new entry is needed. Therefore,
* this implies there is not an entry in the
* reserve map.
*
* For shared mappings, no entry in the map indicates
* no reservation. We are done.
*/
if (!(vma->vm_flags & VM_MAYSHARE))
/*
* For private mappings, no entry indicates
* a reservation is present. Since we can
* not add an entry, set hugetlb_restore_reserve
* on the folio so reserve count will be
* incremented when freed. This reserve will
* be consumed on a subsequent allocation.
*/
folio_set_hugetlb_restore_reserve(folio);
} else
/*
* No reservation present, do nothing
*/
vma_end_reservation(h, vma, address);
}
}
/*
* alloc_and_dissolve_hugetlb_folio - Allocate a new folio and dissolve
* the old one
* @h: struct hstate old page belongs to
* @old_folio: Old folio to dissolve
* @list: List to isolate the page in case we need to
* Returns 0 on success, otherwise negated error.
*/
static int alloc_and_dissolve_hugetlb_folio(struct hstate *h,
struct folio *old_folio, struct list_head *list)
{
gfp_t gfp_mask = htlb_alloc_mask(h) | __GFP_THISNODE;
int nid = folio_nid(old_folio);
struct folio *new_folio = NULL;
int ret = 0;
retry:
spin_lock_irq(&hugetlb_lock);
if (!folio_test_hugetlb(old_folio)) {
/*
* Freed from under us. Drop new_folio too.
*/
goto free_new;
} else if (folio_ref_count(old_folio)) {
bool isolated;
/*
* Someone has grabbed the folio, try to isolate it here.
* Fail with -EBUSY if not possible.
*/
spin_unlock_irq(&hugetlb_lock);
isolated = isolate_hugetlb(old_folio, list);
ret = isolated ? 0 : -EBUSY;
spin_lock_irq(&hugetlb_lock);
goto free_new;
} else if (!folio_test_hugetlb_freed(old_folio)) {
/*
* Folio's refcount is 0 but it has not been enqueued in the
* freelist yet. Race window is small, so we can succeed here if
* we retry.
*/
spin_unlock_irq(&hugetlb_lock);
cond_resched();
goto retry;
} else {
if (!new_folio) {
spin_unlock_irq(&hugetlb_lock);
new_folio = alloc_buddy_hugetlb_folio(h, gfp_mask, nid,
NULL, NULL);
if (!new_folio)
return -ENOMEM;
__prep_new_hugetlb_folio(h, new_folio);
goto retry;
}
/*
* Ok, old_folio is still a genuine free hugepage. Remove it from
* the freelist and decrease the counters. These will be
* incremented again when calling __prep_account_new_huge_page()
* and enqueue_hugetlb_folio() for new_folio. The counters will
* remain stable since this happens under the lock.
*/
remove_hugetlb_folio(h, old_folio, false);
/*
* Ref count on new_folio is already zero as it was dropped
* earlier. It can be directly added to the pool free list.
*/
__prep_account_new_huge_page(h, nid);
enqueue_hugetlb_folio(h, new_folio);
/*
* Folio has been replaced, we can safely free the old one.
*/
spin_unlock_irq(&hugetlb_lock);
update_and_free_hugetlb_folio(h, old_folio, false);
}
return ret;
free_new:
spin_unlock_irq(&hugetlb_lock);
if (new_folio) {
/* Folio has a zero ref count, but needs a ref to be freed */
folio_ref_unfreeze(new_folio, 1);
update_and_free_hugetlb_folio(h, new_folio, false);
}
return ret;
}
int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
{
struct hstate *h;
struct folio *folio = page_folio(page);
int ret = -EBUSY;
/*
* The page might have been dissolved from under our feet, so make sure
* to carefully check the state under the lock.
* Return success when racing as if we dissolved the page ourselves.
*/
spin_lock_irq(&hugetlb_lock);
if (folio_test_hugetlb(folio)) {
h = folio_hstate(folio);
} else {
spin_unlock_irq(&hugetlb_lock);
return 0;
}
spin_unlock_irq(&hugetlb_lock);
/*
* Fence off gigantic pages as there is a cyclic dependency between
* alloc_contig_range and them. Return -ENOMEM as this has the effect
* of bailing out right away without further retrying.
*/
if (hstate_is_gigantic(h))
return -ENOMEM;
if (folio_ref_count(folio) && isolate_hugetlb(folio, list))
ret = 0;
else if (!folio_ref_count(folio))
ret = alloc_and_dissolve_hugetlb_folio(h, folio, list);
return ret;
}
struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
unsigned long addr, int avoid_reserve)
{
struct hugepage_subpool *spool = subpool_vma(vma);
struct hstate *h = hstate_vma(vma);
struct folio *folio;
long map_chg, map_commit, nr_pages = pages_per_huge_page(h);
long gbl_chg;
int memcg_charge_ret, ret, idx;
struct hugetlb_cgroup *h_cg = NULL;
struct mem_cgroup *memcg;
bool deferred_reserve;
gfp_t gfp = htlb_alloc_mask(h) | __GFP_RETRY_MAYFAIL;
memcg = get_mem_cgroup_from_current();
memcg_charge_ret = mem_cgroup_hugetlb_try_charge(memcg, gfp, nr_pages);
if (memcg_charge_ret == -ENOMEM) {
mem_cgroup_put(memcg);
return ERR_PTR(-ENOMEM);
}
idx = hstate_index(h);
/*
* Examine the region/reserve map to determine if the process
* has a reservation for the page to be allocated. A return
* code of zero indicates a reservation exists (no change).
*/
map_chg = gbl_chg = vma_needs_reservation(h, vma, addr);
if (map_chg < 0) {
if (!memcg_charge_ret)
mem_cgroup_cancel_charge(memcg, nr_pages);
mem_cgroup_put(memcg);
return ERR_PTR(-ENOMEM);
}
/*
* Processes that did not create the mapping will have no
* reserves as indicated by the region/reserve map. Check
* that the allocation will not exceed the subpool limit.
* Allocations for MAP_NORESERVE mappings also need to be
* checked against any subpool limit.
*/
if (map_chg || avoid_reserve) {
gbl_chg = hugepage_subpool_get_pages(spool, 1);
if (gbl_chg < 0)
goto out_end_reservation;
/*
* Even though there was no reservation in the region/reserve
* map, there could be reservations associated with the
* subpool that can be used. This would be indicated if the
* return value of hugepage_subpool_get_pages() is zero.
* However, if avoid_reserve is specified we still avoid even
* the subpool reservations.
*/
if (avoid_reserve)
gbl_chg = 1;
}
/* If this allocation is not consuming a reservation, charge it now.
*/
deferred_reserve = map_chg || avoid_reserve;
if (deferred_reserve) {
ret = hugetlb_cgroup_charge_cgroup_rsvd(
idx, pages_per_huge_page(h), &h_cg);
if (ret)
goto out_subpool_put;
}
ret = hugetlb_cgroup_charge_cgroup(idx, pages_per_huge_page(h), &h_cg);
if (ret)
goto out_uncharge_cgroup_reservation;
spin_lock_irq(&hugetlb_lock);
/*
* glb_chg is passed to indicate whether or not a page must be taken
* from the global free pool (global change). gbl_chg == 0 indicates
* a reservation exists for the allocation.
*/
folio = dequeue_hugetlb_folio_vma(h, vma, addr, avoid_reserve, gbl_chg);
if (!folio) {
spin_unlock_irq(&hugetlb_lock);
folio = alloc_buddy_hugetlb_folio_with_mpol(h, vma, addr);
if (!folio)
goto out_uncharge_cgroup;
spin_lock_irq(&hugetlb_lock);
if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
folio_set_hugetlb_restore_reserve(folio);
h->resv_huge_pages--;
}
list_add(&folio->lru, &h->hugepage_activelist);
folio_ref_unfreeze(folio, 1);
/* Fall through */
}
hugetlb_cgroup_commit_charge(idx, pages_per_huge_page(h), h_cg, folio);
/* If allocation is not consuming a reservation, also store the
* hugetlb_cgroup pointer on the page.
*/
if (deferred_reserve) {
hugetlb_cgroup_commit_charge_rsvd(idx, pages_per_huge_page(h),
h_cg, folio);
}
spin_unlock_irq(&hugetlb_lock);
hugetlb_set_folio_subpool(folio, spool);
map_commit = vma_commit_reservation(h, vma, addr);
if (unlikely(map_chg > map_commit)) {
/*
* The page was added to the reservation map between
* vma_needs_reservation and vma_commit_reservation.
* This indicates a race with hugetlb_reserve_pages.
* Adjust for the subpool count incremented above AND
* in hugetlb_reserve_pages for the same page. Also,
* the reservation count added in hugetlb_reserve_pages
* no longer applies.
*/
long rsv_adjust;
rsv_adjust = hugepage_subpool_put_pages(spool, 1);
hugetlb_acct_memory(h, -rsv_adjust);
if (deferred_reserve) {
spin_lock_irq(&hugetlb_lock);
hugetlb_cgroup_uncharge_folio_rsvd(hstate_index(h),
pages_per_huge_page(h), folio);
spin_unlock_irq(&hugetlb_lock);
}
}
if (!memcg_charge_ret)
mem_cgroup_commit_charge(folio, memcg);
mem_cgroup_put(memcg);
return folio;
out_uncharge_cgroup:
hugetlb_cgroup_uncharge_cgroup(idx, pages_per_huge_page(h), h_cg);
out_uncharge_cgroup_reservation:
if (deferred_reserve)
hugetlb_cgroup_uncharge_cgroup_rsvd(idx, pages_per_huge_page(h),
h_cg);
out_subpool_put:
if (map_chg || avoid_reserve)
hugepage_subpool_put_pages(spool, 1);
out_end_reservation:
vma_end_reservation(h, vma, addr);
if (!memcg_charge_ret)
mem_cgroup_cancel_charge(memcg, nr_pages);
mem_cgroup_put(memcg);
return ERR_PTR(-ENOSPC);
}
int alloc_bootmem_huge_page(struct hstate *h, int nid)
__attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
int __alloc_bootmem_huge_page(struct hstate *h, int nid)
{
struct huge_bootmem_page *m = NULL; /* initialize for clang */
int nr_nodes, node = nid;
/* do node specific alloc */
if (nid !=<