diff options
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 5 | ||||
| -rw-r--r-- | include/linux/huge_mm.h | 15 | ||||
| -rw-r--r-- | mm/huge_memory.c | 13 | ||||
| -rw-r--r-- | mm/migrate.c | 4 | ||||
| -rw-r--r-- | mm/page_alloc.c | 5 | ||||
| -rw-r--r-- | mm/rmap.c | 1 |
6 files changed, 37 insertions, 6 deletions
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index 79435c537e21..d6874234a09a 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -551,6 +551,11 @@ split_deferred it would free up some memory. Pages on split queue are going to be split under memory pressure, if splitting is possible. +nr_anon + the number of anonymous THP we have in the whole system. These THPs + might be currently entirely mapped or have partially unmapped/unused + subpages. + 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 4c32058cacfe..2ee2971e4e10 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -126,6 +126,7 @@ enum mthp_stat_item { MTHP_STAT_SPLIT, MTHP_STAT_SPLIT_FAILED, MTHP_STAT_SPLIT_DEFERRED, + MTHP_STAT_NR_ANON, __MTHP_STAT_COUNT }; @@ -136,14 +137,24 @@ struct mthp_stat { DECLARE_PER_CPU(struct mthp_stat, mthp_stats); -static inline void count_mthp_stat(int order, enum mthp_stat_item item) +static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta) { if (order <= 0 || order > PMD_ORDER) return; - this_cpu_inc(mthp_stats.stats[order][item]); + this_cpu_add(mthp_stats.stats[order][item], delta); +} + +static inline void count_mthp_stat(int order, enum mthp_stat_item item) +{ + mod_mthp_stat(order, item, 1); } + #else +static inline void mod_mthp_stat(int order, enum mthp_stat_item item, int delta) +{ +} + static inline void count_mthp_stat(int order, enum mthp_stat_item item) { } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3e872ee724cc..ea57c51d478d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -597,6 +597,7 @@ DEFINE_MTHP_STAT_ATTR(shmem_fallback_charge, MTHP_STAT_SHMEM_FALLBACK_CHARGE); 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); static struct attribute *anon_stats_attrs[] = { &anon_fault_alloc_attr.attr, @@ -607,6 +608,7 @@ static struct attribute *anon_stats_attrs[] = { &swpout_fallback_attr.attr, #endif &split_deferred_attr.attr, + &nr_anon_attr.attr, NULL, }; @@ -3314,8 +3316,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, struct deferred_split *ds_queue = get_deferred_split_queue(folio); /* reset xarray order to new order after split */ XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order); - struct anon_vma *anon_vma = NULL; + bool is_anon = folio_test_anon(folio); struct address_space *mapping = NULL; + struct anon_vma *anon_vma = NULL; int order = folio_order(folio); int extra_pins, ret; pgoff_t end; @@ -3327,7 +3330,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, if (new_order >= folio_order(folio)) return -EINVAL; - if (folio_test_anon(folio)) { + if (is_anon) { /* order-1 is not supported for anonymous THP. */ if (new_order == 1) { VM_WARN_ONCE(1, "Cannot split to order-1 folio"); @@ -3367,7 +3370,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, if (folio_test_writeback(folio)) return -EBUSY; - if (folio_test_anon(folio)) { + if (is_anon) { /* * The caller does not necessarily hold an mmap_lock that would * prevent the anon_vma disappearing so we first we take a @@ -3480,6 +3483,10 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, } } + if (is_anon) { + mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1); + mod_mthp_stat(new_order, MTHP_STAT_NR_ANON, 1 << (order - new_order)); + } __split_huge_page(page, list, end, new_order); ret = 0; } else { diff --git a/mm/migrate.c b/mm/migrate.c index ba4893d42618..6f9c62c746be 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -449,6 +449,8 @@ static int __folio_migrate_mapping(struct address_space *mapping, /* No turning back from here */ newfolio->index = folio->index; newfolio->mapping = folio->mapping; + if (folio_test_anon(folio) && folio_test_large(folio)) + mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); if (folio_test_swapbacked(folio)) __folio_set_swapbacked(newfolio); @@ -473,6 +475,8 @@ static int __folio_migrate_mapping(struct address_space *mapping, */ newfolio->index = folio->index; newfolio->mapping = folio->mapping; + if (folio_test_anon(folio) && folio_test_large(folio)) + mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); folio_ref_add(newfolio, nr); /* add cache reference */ if (folio_test_swapbacked(folio)) { __folio_set_swapbacked(newfolio); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6dd0b409e3c2..3469ca78bf7a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1084,8 +1084,11 @@ __always_inline bool free_pages_prepare(struct page *page, (page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP; } } - if (PageMappingFlags(page)) + if (PageMappingFlags(page)) { + if (PageAnon(page)) + mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1); page->mapping = NULL; + } if (is_check_pages_enabled()) { if (free_page_is_bad(page)) bad++; diff --git a/mm/rmap.c b/mm/rmap.c index 1103a536e474..78529cf0fd66 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1467,6 +1467,7 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, } __folio_mod_stat(folio, nr, nr_pmdmapped); + mod_mthp_stat(folio_order(folio), MTHP_STAT_NR_ANON, 1); } static __always_inline void __folio_add_file_rmap(struct folio *folio, |