diff options
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 7 | ||||
| -rw-r--r-- | include/linux/huge_mm.h | 1 | ||||
| -rw-r--r-- | mm/huge_memory.c | 6 |
3 files changed, 14 insertions, 0 deletions
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index d6874234a09a..56a086900651 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -556,6 +556,13 @@ nr_anon might be currently entirely mapped or have partially unmapped/unused subpages. +nr_anon_partially_mapped + the number of anonymous THP which are likely partially mapped, possibly + wasting memory, and have been queued for deferred memory reclamation. + Note that in corner some cases (e.g., failed migration), we might detect + an anonymous THP as "partially mapped" and count it here, even though it + is not actually partially mapped anymore. + As the system ages, allocating huge pages may be expensive as the system uses memory compaction to copy data around memory to free a huge page for use. There are some counters in ``/proc/vmstat`` to help diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 2ee2971e4e10..4902e2f7e896 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -127,6 +127,7 @@ enum mthp_stat_item { MTHP_STAT_SPLIT_FAILED, MTHP_STAT_SPLIT_DEFERRED, MTHP_STAT_NR_ANON, + MTHP_STAT_NR_ANON_PARTIALLY_MAPPED, __MTHP_STAT_COUNT }; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index ea57c51d478d..efc625086dc7 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -598,6 +598,7 @@ DEFINE_MTHP_STAT_ATTR(split, MTHP_STAT_SPLIT); DEFINE_MTHP_STAT_ATTR(split_failed, MTHP_STAT_SPLIT_FAILED); DEFINE_MTHP_STAT_ATTR(split_deferred, MTHP_STAT_SPLIT_DEFERRED); DEFINE_MTHP_STAT_ATTR(nr_anon, MTHP_STAT_NR_ANON); +DEFINE_MTHP_STAT_ATTR(nr_anon_partially_mapped, MTHP_STAT_NR_ANON_PARTIALLY_MAPPED); static struct attribute *anon_stats_attrs[] = { &anon_fault_alloc_attr.attr, @@ -609,6 +610,7 @@ static struct attribute *anon_stats_attrs[] = { #endif &split_deferred_attr.attr, &nr_anon_attr.attr, + &nr_anon_partially_mapped_attr.attr, NULL, }; @@ -3457,6 +3459,7 @@ 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); /* * Reinitialize page_deferred_list after removing the * page from the split_queue, otherwise a subsequent @@ -3523,6 +3526,7 @@ 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); list_del_init(&folio->_deferred_list); } spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); @@ -3564,6 +3568,7 @@ void deferred_split_folio(struct folio *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); list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); ds_queue->split_queue_len++; #ifdef CONFIG_MEMCG @@ -3611,6 +3616,7 @@ 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); list_del_init(&folio->_deferred_list); ds_queue->split_queue_len--; } |