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mm: switch deferred split shrinker to list_lru

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The deferred split queue handles cgroups in a suboptimal fashion.  The
queue is per-NUMA node or per-cgroup, not the intersection.  That means on
a cgrouped system, a node-restricted allocation entering reclaim can end
up splitting large pages on other nodes:

        alloc/unmap
          deferred_split_folio()
            list_add_tail(memcg->split_queue)
            set_shrinker_bit(memcg, node, deferred_shrinker_id)

        for_each_zone_zonelist_nodemask(restricted_nodes)
          mem_cgroup_iter()
            shrink_slab(node, memcg)
              shrink_slab_memcg(node, memcg)
                if test_shrinker_bit(memcg, node, deferred_shrinker_id)
                  deferred_split_scan()
                    walks memcg->split_queue

The shrinker bit adds an imperfect guard rail.  As soon as the cgroup has
a single large page on the node of interest, all large pages owned by that
memcg, including those on other nodes, will be split.

list_lru properly sets up per-node, per-cgroup lists.  As a bonus, it
streamlines a lot of the list operations and reclaim walks.  It's used
widely by other major shrinkers already.  Convert the deferred split queue
as well.

The list_lru per-memcg heads are instantiated on demand when the first
object of interest is allocated for a cgroup, by calling
folio_memcg_alloc_deferred().  Add calls to where splittable pages are
created: anon faults, swapin faults, khugepaged collapse.

These calls create all possible node heads for the cgroup at once, so the
migration code (between nodes) doesn't need any special care.

[akpm@linux-foundation.org: fix build with CONFIG_TRANSPARENT_HUGEPAGE=n]
  Link: https://lore.kernel.org/202605281620.lc3rtkBm-lkp@intel.com
[hannes@cmpxchg.org: fix cgroup.memory=nokmem handling]
  Link: https://lore.kernel.org/ah9PGv12mqai84ES@cmpxchg.org
Link: https://lore.kernel.org/20260527204757.2544958-10-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: Usama Arif <usama.arif@linux.dev>
Reviewed-by: Kairui Song <kasong@tencent.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: kernel test robot <lkp@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Johannes Weiner
2026-05-27 16:45:16 -04:00
committed by Andrew Morton
parent 65180e9663
commit fafaeceb89
10 changed files with 160 additions and 288 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
include/linux/huge_mm.h
View File

@@ -439,10 +439,10 @@ static inline int split_huge_page(struct page *page)
{
return split_huge_page_to_list_to_order(page, NULL, 0);
}
int folio_memcg_alloc_deferred(struct folio *folio);
void deferred_split_folio(struct folio *folio, bool partially_mapped);
#ifdef CONFIG_MEMCG
void reparent_deferred_split_queue(struct mem_cgroup *memcg);
#endif
void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long address, bool freeze);
@@ -679,8 +679,15 @@ static inline int try_folio_split_to_order(struct folio *folio,
return -EINVAL;
}
static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {}
static inline void reparent_deferred_split_queue(struct mem_cgroup *memcg) {}
static inline int folio_memcg_alloc_deferred(struct folio *folio)
{
return 0;
}
static inline void deferred_split_folio(struct folio *folio, bool partially_mapped)
{
}
#define split_huge_pmd(__vma, __pmd, __address) \
do { } while (0)

4
include/linux/memcontrol.h
View File

@@ -278,10 +278,6 @@ struct mem_cgroup {
struct memcg_cgwb_frn cgwb_frn[MEMCG_CGWB_FRN_CNT];
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split deferred_split_queue;
#endif
#ifdef CONFIG_LRU_GEN_WALKS_MMU
/* per-memcg mm_struct list */
struct lru_gen_mm_list mm_list;

12
include/linux/mmzone.h
View File

@@ -1431,14 +1431,6 @@ struct zonelist {
*/
extern struct page *mem_map;
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split {
spinlock_t split_queue_lock;
struct list_head split_queue;
unsigned long split_queue_len;
};
#endif
#ifdef CONFIG_MEMORY_FAILURE
/*
* Per NUMA node memory failure handling statistics.
@@ -1564,10 +1556,6 @@ typedef struct pglist_data {
unsigned long first_deferred_pfn;
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split deferred_split_queue;
#endif
#ifdef CONFIG_NUMA_BALANCING
/* start time in ms of current promote rate limit period */
unsigned int nbp_rl_start;

367
mm/huge_memory.c
View File

@@ -14,6 +14,7 @@
#include <linux/mmu_notifier.h>
#include <linux/rmap.h>
#include <linux/swap.h>
#include <linux/list_lru.h>
#include <linux/shrinker.h>
#include <linux/mm_inline.h>
#include <linux/swapops.h>
@@ -67,6 +68,8 @@ unsigned long transparent_hugepage_flags __read_mostly =
(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)|
(1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
static struct lock_class_key deferred_split_key;
static struct list_lru deferred_split_lru;
static struct shrinker *deferred_split_shrinker;
static unsigned long deferred_split_count(struct shrinker *shrink,
struct shrink_control *sc);
@@ -932,15 +935,28 @@ static inline void hugepage_exit_sysfs(struct kobject *hugepage_kobj)
}
#endif /* CONFIG_SYSFS */
int folio_memcg_alloc_deferred(struct folio *folio)
{
if (mem_cgroup_disabled())
return 0;
return folio_memcg_list_lru_alloc(folio, &deferred_split_lru, GFP_KERNEL);
}
static int __init thp_shrinker_init(void)
{
deferred_split_shrinker = shrinker_alloc(SHRINKER_NUMA_AWARE |
SHRINKER_MEMCG_AWARE |
SHRINKER_NONSLAB,
SHRINKER_MEMCG_AWARE,
"thp-deferred_split");
if (!deferred_split_shrinker)
return -ENOMEM;
if (list_lru_init_memcg_key(&deferred_split_lru,
deferred_split_shrinker,
&deferred_split_key)) {
shrinker_free(deferred_split_shrinker);
return -ENOMEM;
}
deferred_split_shrinker->count_objects = deferred_split_count;
deferred_split_shrinker->scan_objects = deferred_split_scan;
shrinker_register(deferred_split_shrinker);
@@ -962,6 +978,7 @@ static int __init thp_shrinker_init(void)
huge_zero_folio_shrinker = shrinker_alloc(0, "thp-zero");
if (!huge_zero_folio_shrinker) {
shrinker_free(deferred_split_shrinker);
list_lru_destroy(&deferred_split_lru);
return -ENOMEM;
}
@@ -976,6 +993,7 @@ static void __init thp_shrinker_exit(void)
{
shrinker_free(huge_zero_folio_shrinker);
shrinker_free(deferred_split_shrinker);
list_lru_destroy(&deferred_split_lru);
}
static int __init hugepage_init(void)
@@ -1155,119 +1173,6 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma)
return pmd;
}
static struct deferred_split *split_queue_node(int nid)
{
struct pglist_data *pgdata = NODE_DATA(nid);
return &pgdata->deferred_split_queue;
}
#ifdef CONFIG_MEMCG
static inline
struct mem_cgroup *folio_split_queue_memcg(struct folio *folio,
struct deferred_split *queue)
{
if (mem_cgroup_disabled())
return NULL;
if (split_queue_node(folio_nid(folio)) == queue)
return NULL;
return container_of(queue, struct mem_cgroup, deferred_split_queue);
}
static struct deferred_split *memcg_split_queue(int nid, struct mem_cgroup *memcg)
{
return memcg ? &memcg->deferred_split_queue : split_queue_node(nid);
}
#else
static inline
struct mem_cgroup *folio_split_queue_memcg(struct folio *folio,
struct deferred_split *queue)
{
return NULL;
}
static struct deferred_split *memcg_split_queue(int nid, struct mem_cgroup *memcg)
{
return split_queue_node(nid);
}
#endif
static struct deferred_split *split_queue_lock(int nid, struct mem_cgroup *memcg)
{
struct deferred_split *queue;
retry:
queue = memcg_split_queue(nid, memcg);
spin_lock(&queue->split_queue_lock);
/*
* There is a period between setting memcg to dying and reparenting
* deferred split queue, and during this period the THPs in the deferred
* split queue will be hidden from the shrinker side.
*/
if (unlikely(memcg_is_dying(memcg))) {
spin_unlock(&queue->split_queue_lock);
memcg = parent_mem_cgroup(memcg);
goto retry;
}
return queue;
}
static struct deferred_split *
split_queue_lock_irqsave(int nid, struct mem_cgroup *memcg, unsigned long *flags)
{
struct deferred_split *queue;
retry:
queue = memcg_split_queue(nid, memcg);
spin_lock_irqsave(&queue->split_queue_lock, *flags);
if (unlikely(memcg_is_dying(memcg))) {
spin_unlock_irqrestore(&queue->split_queue_lock, *flags);
memcg = parent_mem_cgroup(memcg);
goto retry;
}
return queue;
}
static struct deferred_split *folio_split_queue_lock(struct folio *folio)
{
struct deferred_split *queue;
rcu_read_lock();
queue = split_queue_lock(folio_nid(folio), folio_memcg(folio));
/*
* The memcg destruction path is acquiring the split queue lock for
* reparenting. Once you have it locked, it's safe to drop the rcu lock.
*/
rcu_read_unlock();
return queue;
}
static struct deferred_split *
folio_split_queue_lock_irqsave(struct folio *folio, unsigned long *flags)
{
struct deferred_split *queue;
rcu_read_lock();
queue = split_queue_lock_irqsave(folio_nid(folio), folio_memcg(folio), flags);
rcu_read_unlock();
return queue;
}
static inline void split_queue_unlock(struct deferred_split *queue)
{
spin_unlock(&queue->split_queue_lock);
}
static inline void split_queue_unlock_irqrestore(struct deferred_split *queue,
unsigned long flags)
{
spin_unlock_irqrestore(&queue->split_queue_lock, flags);
}
static inline bool is_transparent_hugepage(const struct folio *folio)
{
if (!folio_test_large(folio))
@@ -1368,6 +1273,14 @@ static struct folio *vma_alloc_anon_folio_pmd(struct vm_area_struct *vma,
count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE);
return NULL;
}
if (folio_memcg_alloc_deferred(folio)) {
folio_put(folio);
count_vm_event(THP_FAULT_FALLBACK);
count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK);
return NULL;
}
folio_throttle_swaprate(folio, gfp);
/*
@@ -3903,34 +3816,43 @@ static int __folio_freeze_and_split_unmapped(struct folio *folio, unsigned int n
struct folio *end_folio = folio_next(folio);
struct folio *new_folio, *next;
int old_order = folio_order(folio);
struct list_lru_one *lru;
bool dequeue_deferred;
int ret = 0;
struct deferred_split *ds_queue;
VM_WARN_ON_ONCE(!mapping && end);
/* Prevent deferred_split_scan() touching ->_refcount */
ds_queue = folio_split_queue_lock(folio);
/*
* If this folio can be on the deferred split queue, lock out
* the shrinker before freezing the ref. If the shrinker sees
* a 0-ref folio, it assumes it beat folio_put() to the list
* lock and must clean up the LRU state - the same dequeue we
* will do below as part of the split.
*/
dequeue_deferred = folio_test_anon(folio) && old_order > 1;
if (dequeue_deferred) {
struct mem_cgroup *memcg;
rcu_read_lock();
memcg = folio_memcg(folio);
lru = list_lru_lock(&deferred_split_lru,
folio_nid(folio), &memcg);
}
if (folio_ref_freeze(folio, folio_cache_ref_count(folio) + 1)) {
struct swap_cluster_info *ci = NULL;
struct lruvec *lruvec;
if (old_order > 1) {
if (!list_empty(&folio->_deferred_list)) {
ds_queue->split_queue_len--;
/*
* Reinitialize page_deferred_list after removing the
* page from the split_queue, otherwise a subsequent
* split will see list corruption when checking the
* page_deferred_list.
*/
list_del_init(&folio->_deferred_list);
}
if (dequeue_deferred) {
__list_lru_del(&deferred_split_lru, lru,
&folio->_deferred_list, folio_nid(folio));
if (folio_test_partially_mapped(folio)) {
folio_clear_partially_mapped(folio);
mod_mthp_stat(old_order,
MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
}
list_lru_unlock(lru);
rcu_read_unlock();
}
split_queue_unlock(ds_queue);
if (mapping) {
int nr = folio_nr_pages(folio);
@@ -4031,7 +3953,10 @@ static int __folio_freeze_and_split_unmapped(struct folio *folio, unsigned int n
if (ci)
swap_cluster_unlock(ci);
} else {
split_queue_unlock(ds_queue);
if (dequeue_deferred) {
list_lru_unlock(lru);
rcu_read_unlock();
}
return -EAGAIN;
}
@@ -4397,33 +4322,37 @@ int split_folio_to_list(struct folio *folio, struct list_head *list)
* queueing THP splits, and that list is (racily observed to be) non-empty.
*
* It is unsafe to call folio_unqueue_deferred_split() until folio refcount is
* zero: because even when split_queue_lock is held, a non-empty _deferred_list
* might be in use on deferred_split_scan()'s unlocked on-stack list.
* zero: because even when the list_lru lock is held, a non-empty
* _deferred_list might be in use on deferred_split_scan()'s unlocked
* on-stack list.
*
* If memory cgroups are enabled, split_queue_lock is in the mem_cgroup: it is
* therefore important to unqueue deferred split before changing folio memcg.
* The list_lru sublist is determined by folio's memcg: it is therefore
* important to unqueue deferred split before changing folio memcg.
*/
bool __folio_unqueue_deferred_split(struct folio *folio)
{
struct deferred_split *ds_queue;
struct mem_cgroup *memcg;
struct list_lru_one *lru;
int nid = folio_nid(folio);
unsigned long flags;
bool unqueued = false;
WARN_ON_ONCE(folio_ref_count(folio));
WARN_ON_ONCE(!mem_cgroup_disabled() && !folio_memcg_charged(folio));
ds_queue = folio_split_queue_lock_irqsave(folio, &flags);
if (!list_empty(&folio->_deferred_list)) {
ds_queue->split_queue_len--;
rcu_read_lock();
memcg = folio_memcg(folio);
lru = list_lru_lock_irqsave(&deferred_split_lru, nid, &memcg, &flags);
if (__list_lru_del(&deferred_split_lru, lru, &folio->_deferred_list, nid)) {
if (folio_test_partially_mapped(folio)) {
folio_clear_partially_mapped(folio);
mod_mthp_stat(folio_order(folio),
MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
}
list_del_init(&folio->_deferred_list);
unqueued = true;
}
split_queue_unlock_irqrestore(ds_queue, flags);
list_lru_unlock_irqrestore(lru, &flags);
rcu_read_unlock();
return unqueued; /* useful for debug warnings */
}
@@ -4431,7 +4360,9 @@ bool __folio_unqueue_deferred_split(struct folio *folio)
/* partially_mapped=false won't clear PG_partially_mapped folio flag */
void deferred_split_folio(struct folio *folio, bool partially_mapped)
{
struct deferred_split *ds_queue;
struct list_lru_one *lru;
int nid;
struct mem_cgroup *memcg;
unsigned long flags;
/*
@@ -4454,7 +4385,11 @@ void deferred_split_folio(struct folio *folio, bool partially_mapped)
if (folio_test_swapcache(folio))
return;
ds_queue = folio_split_queue_lock_irqsave(folio, &flags);
nid = folio_nid(folio);
rcu_read_lock();
memcg = folio_memcg(folio);
lru = list_lru_lock_irqsave(&deferred_split_lru, nid, &memcg, &flags);
if (partially_mapped) {
if (!folio_test_partially_mapped(folio)) {
folio_set_partially_mapped(folio);
@@ -4462,36 +4397,20 @@ void deferred_split_folio(struct folio *folio, bool partially_mapped)
count_vm_event(THP_DEFERRED_SPLIT_PAGE);
count_mthp_stat(folio_order(folio), MTHP_STAT_SPLIT_DEFERRED);
mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, 1);
}
} else {
/* partially mapped folios cannot become non-partially mapped */
VM_WARN_ON_FOLIO(folio_test_partially_mapped(folio), folio);
}
if (list_empty(&folio->_deferred_list)) {
struct mem_cgroup *memcg;
memcg = folio_split_queue_memcg(folio, ds_queue);
list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
ds_queue->split_queue_len++;
if (memcg)
set_shrinker_bit(memcg, folio_nid(folio),
shrinker_id(deferred_split_shrinker));
}
split_queue_unlock_irqrestore(ds_queue, flags);
__list_lru_add(&deferred_split_lru, lru, &folio->_deferred_list, nid, memcg);
list_lru_unlock_irqrestore(lru, &flags);
rcu_read_unlock();
}
static unsigned long deferred_split_count(struct shrinker *shrink,
struct shrink_control *sc)
{
struct pglist_data *pgdata = NODE_DATA(sc->nid);
struct deferred_split *ds_queue = &pgdata->deferred_split_queue;
#ifdef CONFIG_MEMCG
if (sc->memcg)
ds_queue = &sc->memcg->deferred_split_queue;
#endif
return READ_ONCE(ds_queue->split_queue_len);
return list_lru_shrink_count(&deferred_split_lru, sc);
}
static bool thp_underused(struct folio *folio)
@@ -4521,45 +4440,49 @@ static bool thp_underused(struct folio *folio)
return false;
}
static enum lru_status deferred_split_isolate(struct list_head *item,
struct list_lru_one *lru,
void *cb_arg)
{
struct folio *folio = container_of(item, struct folio, _deferred_list);
struct list_head *freeable = cb_arg;
if (folio_try_get(folio)) {
list_lru_isolate_move(lru, item, freeable);
return LRU_REMOVED;
}
/*
* We lost race with folio_put(). Read folio state before the
* isolate: folio_unqueue_deferred_split() checks list_empty()
* locklessly, so once removed the folio can be freed any time.
*/
if (folio_test_partially_mapped(folio)) {
folio_clear_partially_mapped(folio);
mod_mthp_stat(folio_order(folio),
MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
}
list_lru_isolate(lru, item);
return LRU_REMOVED;
}
static unsigned long deferred_split_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct deferred_split *ds_queue;
unsigned long flags;
LIST_HEAD(dispose);
struct folio *folio, *next;
int split = 0, i;
struct folio_batch fbatch;
int split = 0;
unsigned long isolated;
folio_batch_init(&fbatch);
isolated = list_lru_shrink_walk_irq(&deferred_split_lru, sc,
deferred_split_isolate, &dispose);
retry:
ds_queue = split_queue_lock_irqsave(sc->nid, sc->memcg, &flags);
/* Take pin on all head pages to avoid freeing them under us */
list_for_each_entry_safe(folio, next, &ds_queue->split_queue,
_deferred_list) {
if (folio_try_get(folio)) {
folio_batch_add(&fbatch, folio);
} else if (folio_test_partially_mapped(folio)) {
/* We lost race with folio_put() */
folio_clear_partially_mapped(folio);
mod_mthp_stat(folio_order(folio),
MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
}
list_del_init(&folio->_deferred_list);
ds_queue->split_queue_len--;
if (!--sc->nr_to_scan)
break;
if (!folio_batch_space(&fbatch))
break;
}
split_queue_unlock_irqrestore(ds_queue, flags);
for (i = 0; i < folio_batch_count(&fbatch); i++) {
list_for_each_entry_safe(folio, next, &dispose, _deferred_list) {
bool did_split = false;
bool underused = false;
struct deferred_split *fqueue;
folio = fbatch.folios[i];
list_del_init(&folio->_deferred_list);
if (!folio_test_partially_mapped(folio)) {
/*
* See try_to_map_unused_to_zeropage(): we cannot
@@ -4588,63 +4511,23 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
* underused, then consider it used and don't add it back to
* split_queue.
*/
if (did_split || !folio_test_partially_mapped(folio))
continue;
if (!did_split && folio_test_partially_mapped(folio)) {
requeue:
/*
* Add back partially mapped folios, or underused folios that
* we could not lock this round.
*/
fqueue = folio_split_queue_lock_irqsave(folio, &flags);
if (list_empty(&folio->_deferred_list)) {
list_add_tail(&folio->_deferred_list, &fqueue->split_queue);
fqueue->split_queue_len++;
rcu_read_lock();
list_lru_add_irq(&deferred_split_lru,
&folio->_deferred_list,
folio_nid(folio),
folio_memcg(folio));
rcu_read_unlock();
}
split_queue_unlock_irqrestore(fqueue, flags);
}
folios_put(&fbatch);
if (sc->nr_to_scan && !list_empty(&ds_queue->split_queue)) {
cond_resched();
goto retry;
folio_put(folio);
}
/*
* Stop shrinker if we didn't split any page, but the queue is empty.
* This can happen if pages were freed under us.
*/
if (!split && list_empty(&ds_queue->split_queue))
if (!split && !isolated)
return SHRINK_STOP;
return split;
}
#ifdef CONFIG_MEMCG
void reparent_deferred_split_queue(struct mem_cgroup *memcg)
{
struct mem_cgroup *parent = parent_mem_cgroup(memcg);
struct deferred_split *ds_queue = &memcg->deferred_split_queue;
struct deferred_split *parent_ds_queue = &parent->deferred_split_queue;
int nid;
spin_lock_irq(&ds_queue->split_queue_lock);
spin_lock_nested(&parent_ds_queue->split_queue_lock, SINGLE_DEPTH_NESTING);
if (!ds_queue->split_queue_len)
goto unlock;
list_splice_tail_init(&ds_queue->split_queue, &parent_ds_queue->split_queue);
parent_ds_queue->split_queue_len += ds_queue->split_queue_len;
ds_queue->split_queue_len = 0;
for_each_node(nid)
set_shrinker_bit(parent, nid, shrinker_id(deferred_split_shrinker));
unlock:
spin_unlock(&parent_ds_queue->split_queue_lock);
spin_unlock_irq(&ds_queue->split_queue_lock);
}
#endif
#ifdef CONFIG_DEBUG_FS
static void split_huge_pages_all(void)
{

2
mm/internal.h
View File

@@ -852,7 +852,7 @@ static inline bool folio_unqueue_deferred_split(struct folio *folio)
/*
* At this point, there is no one trying to add the folio to
* deferred_list. If folio is not in deferred_list, it's safe
* to check without acquiring the split_queue_lock.
* to check without acquiring the list_lru lock.
*/
if (data_race(list_empty(&folio->_deferred_list)))
return false;

5
mm/khugepaged.c
View File

@@ -1123,6 +1123,11 @@ static enum scan_result collapse_huge_page(struct mm_struct *mm, unsigned long a
if (result != SCAN_SUCCEED)
goto out_nolock;
if (folio_memcg_alloc_deferred(folio)) {
result = SCAN_ALLOC_HUGE_PAGE_FAIL;
goto out_nolock;
}
mmap_read_lock(mm);
result = hugepage_vma_revalidate(mm, address, true, &vma, cc);
if (result != SCAN_SUCCEED) {

12
mm/memcontrol.c
View File

@@ -4143,11 +4143,6 @@ static struct mem_cgroup *mem_cgroup_alloc(struct mem_cgroup *parent)
for (i = 0; i < MEMCG_CGWB_FRN_CNT; i++)
memcg->cgwb_frn[i].done =
__WB_COMPLETION_INIT(&memcg_cgwb_frn_waitq);
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
spin_lock_init(&memcg->deferred_split_queue.split_queue_lock);
INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue);
memcg->deferred_split_queue.split_queue_len = 0;
#endif
lru_gen_init_memcg(memcg);
return memcg;
@@ -4299,11 +4294,10 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
zswap_memcg_offline_cleanup(memcg);
memcg_offline_kmem(memcg);
reparent_deferred_split_queue(memcg);
/*
* The reparenting of objcg must be after the reparenting of the
* list_lru and deferred_split_queue above, which ensures that they will
* not mistakenly get the parent list_lru and deferred_split_queue.
* The reparenting of objcg must be after the reparenting of
* the list_lru in memcg_offline_kmem(), which ensures that
* they will not mistakenly get the parent list_lru.
*/
memcg_reparent_objcgs(memcg);
reparent_shrinker_deferred(memcg);

4
mm/memory.c
View File

@@ -5222,6 +5222,10 @@ static struct folio *alloc_anon_folio(struct vm_fault *vmf)
folio_put(folio);
goto next;
}
if (order > 1 && folio_memcg_alloc_deferred(folio)) {
folio_put(folio);
goto fallback;
}
folio_throttle_swaprate(folio, gfp);
/*
* When a folio is not zeroed during allocation

15
mm/mm_init.c
View File

@@ -1373,19 +1373,6 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
pr_debug("On node %d totalpages: %lu\n", pgdat->node_id, realtotalpages);
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void pgdat_init_split_queue(struct pglist_data *pgdat)
{
struct deferred_split *ds_queue = &pgdat->deferred_split_queue;
spin_lock_init(&ds_queue->split_queue_lock);
INIT_LIST_HEAD(&ds_queue->split_queue);
ds_queue->split_queue_len = 0;
}
#else
static void pgdat_init_split_queue(struct pglist_data *pgdat) {}
#endif
#ifdef CONFIG_COMPACTION
static void pgdat_init_kcompactd(struct pglist_data *pgdat)
{
@@ -1401,8 +1388,6 @@ static void __meminit pgdat_init_internals(struct pglist_data *pgdat)
pgdat_resize_init(pgdat);
pgdat_kswapd_lock_init(pgdat);
pgdat_init_split_queue(pgdat);
pgdat_init_kcompactd(pgdat);
init_waitqueue_head(&pgdat->kswapd_wait);

10
mm/swap_state.c
View File

@@ -465,6 +465,16 @@ static struct folio *__swap_cache_alloc(struct swap_cluster_info *ci,
return ERR_PTR(-ENOMEM);
}
if (order > 1 && folio_memcg_alloc_deferred(folio)) {
spin_lock(&ci->lock);
__swap_cache_do_del_folio(ci, folio, entry, shadow);
spin_unlock(&ci->lock);
folio_unlock(folio);
/* nr_pages refs from swap cache, 1 from allocation */
folio_put_refs(folio, nr_pages + 1);
return ERR_PTR(-ENOMEM);
}
/* memsw uncharges swap when folio is added to swap cache */
memcg1_swapin(folio);
if (shadow)