summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--include/linux/huge_mm.h4
-rw-r--r--include/linux/page-flags.h13
-rw-r--r--mm/huge_memory.c41
-rw-r--r--mm/memcontrol.c3
-rw-r--r--mm/migrate.c3
-rw-r--r--mm/page_alloc.c5
-rw-r--r--mm/rmap.c5
-rw-r--r--mm/vmscan.c3
8 files changed, 56 insertions, 21 deletions
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 4902e2f7e896..e3896ebf0f94 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -333,7 +333,7 @@ static inline int split_huge_page(struct page *page)
{
return split_huge_page_to_list_to_order(page, NULL, 0);
}
-void deferred_split_folio(struct folio *folio);
+void deferred_split_folio(struct folio *folio, bool partially_mapped);
void __split_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
unsigned long address, bool freeze, struct folio *folio);
@@ -507,7 +507,7 @@ static inline int split_huge_page(struct page *page)
{
return 0;
}
-static inline void deferred_split_folio(struct folio *folio) {}
+static inline void deferred_split_folio(struct folio *folio, bool partially_mapped) {}
#define split_huge_pmd(__vma, __pmd, __address) \
do { } while (0)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 2175ebceb41c..1b3a76710487 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -186,6 +186,7 @@ enum pageflags {
/* At least one page in this folio has the hwpoison flag set */
PG_has_hwpoisoned = PG_active,
PG_large_rmappable = PG_workingset, /* anon or file-backed */
+ PG_partially_mapped = PG_reclaim, /* was identified to be partially mapped */
};
#define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1)
@@ -859,8 +860,18 @@ static inline void ClearPageCompound(struct page *page)
ClearPageHead(page);
}
FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE)
+FOLIO_TEST_FLAG(partially_mapped, FOLIO_SECOND_PAGE)
+/*
+ * PG_partially_mapped is protected by deferred_split split_queue_lock,
+ * so its safe to use non-atomic set/clear.
+ */
+__FOLIO_SET_FLAG(partially_mapped, FOLIO_SECOND_PAGE)
+__FOLIO_CLEAR_FLAG(partially_mapped, FOLIO_SECOND_PAGE)
#else
FOLIO_FLAG_FALSE(large_rmappable)
+FOLIO_TEST_FLAG_FALSE(partially_mapped)
+__FOLIO_SET_FLAG_NOOP(partially_mapped)
+__FOLIO_CLEAR_FLAG_NOOP(partially_mapped)
#endif
#define PG_head_mask ((1UL << PG_head))
@@ -1171,7 +1182,7 @@ static __always_inline void __ClearPageAnonExclusive(struct page *page)
*/
#define PAGE_FLAGS_SECOND \
(0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \
- 1UL << PG_large_rmappable)
+ 1UL << PG_large_rmappable | 1UL << PG_partially_mapped)
#define PAGE_FLAGS_PRIVATE \
(1UL << PG_private | 1UL << PG_private_2)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 6b69309e002f..9bc435bef2e6 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3459,7 +3459,11 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
if (folio_order(folio) > 1 &&
!list_empty(&folio->_deferred_list)) {
ds_queue->split_queue_len--;
- mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
+ if (folio_test_partially_mapped(folio)) {
+ __folio_clear_partially_mapped(folio);
+ mod_mthp_stat(folio_order(folio),
+ MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
+ }
/*
* Reinitialize page_deferred_list after removing the
* page from the split_queue, otherwise a subsequent
@@ -3526,13 +3530,18 @@ void __folio_undo_large_rmappable(struct folio *folio)
spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
if (!list_empty(&folio->_deferred_list)) {
ds_queue->split_queue_len--;
- mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
+ 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);
}
spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags);
}
-void deferred_split_folio(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 = get_deferred_split_queue(folio);
#ifdef CONFIG_MEMCG
@@ -3560,15 +3569,21 @@ void deferred_split_folio(struct folio *folio)
if (folio_test_swapcache(folio))
return;
- if (!list_empty(&folio->_deferred_list))
- return;
-
spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
+ if (partially_mapped) {
+ if (!folio_test_partially_mapped(folio)) {
+ __folio_set_partially_mapped(folio);
+ if (folio_test_pmd_mappable(folio))
+ 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)) {
- if (folio_test_pmd_mappable(folio))
- 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);
list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
ds_queue->split_queue_len++;
#ifdef CONFIG_MEMCG
@@ -3616,7 +3631,11 @@ static unsigned long deferred_split_scan(struct shrinker *shrink,
list_move(&folio->_deferred_list, &list);
} else {
/* We lost race with folio_put() */
- mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, -1);
+ 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);
ds_queue->split_queue_len--;
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0370ce03ce4c..5abff3b0cae5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4645,7 +4645,8 @@ static void uncharge_folio(struct folio *folio, struct uncharge_gather *ug)
VM_BUG_ON_FOLIO(folio_test_lru(folio), folio);
VM_BUG_ON_FOLIO(folio_order(folio) > 1 &&
!folio_test_hugetlb(folio) &&
- !list_empty(&folio->_deferred_list), folio);
+ !list_empty(&folio->_deferred_list) &&
+ folio_test_partially_mapped(folio), folio);
/*
* Nobody should be changing or seriously looking at
diff --git a/mm/migrate.c b/mm/migrate.c
index d039863e014b..35cc9d35064b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1766,7 +1766,8 @@ static int migrate_pages_batch(struct list_head *from,
* use _deferred_list.
*/
if (nr_pages > 2 &&
- !list_empty(&folio->_deferred_list)) {
+ !list_empty(&folio->_deferred_list) &&
+ folio_test_partially_mapped(folio)) {
if (!try_split_folio(folio, split_folios, mode)) {
nr_failed++;
stats->nr_thp_failed += is_thp;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 23509b823e2b..ea4c44c3cfc0 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -962,8 +962,9 @@ static int free_tail_page_prepare(struct page *head_page, struct page *page)
break;
case 2:
/* the second tail page: deferred_list overlaps ->mapping */
- if (unlikely(!list_empty(&folio->_deferred_list))) {
- bad_page(page, "on deferred list");
+ if (unlikely(!list_empty(&folio->_deferred_list) &&
+ folio_test_partially_mapped(folio))) {
+ bad_page(page, "partially mapped folio on deferred list");
goto out;
}
break;
diff --git a/mm/rmap.c b/mm/rmap.c
index 78529cf0fd66..a8797d1b3d49 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1579,8 +1579,9 @@ static __always_inline void __folio_remove_rmap(struct folio *folio,
* Check partially_mapped first to ensure it is a large folio.
*/
if (partially_mapped && folio_test_anon(folio) &&
- list_empty(&folio->_deferred_list))
- deferred_split_folio(folio);
+ !folio_test_partially_mapped(folio))
+ deferred_split_folio(folio, true);
+
__folio_mod_stat(folio, -nr, -nr_pmdmapped);
/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1b1fad0c1e11..8163b24bec75 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1238,7 +1238,8 @@ retry:
* Split partially mapped folios right away.
* We can free the unmapped pages without IO.
*/
- if (data_race(!list_empty(&folio->_deferred_list)) &&
+ if (data_race(!list_empty(&folio->_deferred_list) &&
+ folio_test_partially_mapped(folio)) &&
split_folio_to_list(folio, folio_list))
goto activate_locked;
}
generated by cgit (git 2.34.1) at 2025-05-10 02:27:26 +0000