Currently, the split counters in THP statistics no longer include PTE-mapped mTHP. Therefore, we propose introducing per-order mTHP split counters to monitor the frequency of mTHP splits. This will help developers better analyze and optimize system performance. /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats split split_failed split_deferred Signed-off-by: Mingzhe Yang <mingzhe.yang@xxxxxx> Signed-off-by: Lance Yang <ioworker0@xxxxxxxxx> --- include/linux/huge_mm.h | 3 +++ mm/huge_memory.c | 19 ++++++++++++++----- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h index 212cca384d7e..cee3c5da8f0e 100644 --- a/include/linux/huge_mm.h +++ b/include/linux/huge_mm.h @@ -284,6 +284,9 @@ enum mthp_stat_item { MTHP_STAT_FILE_ALLOC, MTHP_STAT_FILE_FALLBACK, MTHP_STAT_FILE_FALLBACK_CHARGE, + MTHP_STAT_SPLIT, + MTHP_STAT_SPLIT_FAILED, + MTHP_STAT_SPLIT_DEFERRED, __MTHP_STAT_COUNT }; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index c7ce28f6b7f3..a633206375af 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -559,6 +559,9 @@ DEFINE_MTHP_STAT_ATTR(swpout_fallback, MTHP_STAT_SWPOUT_FALLBACK); DEFINE_MTHP_STAT_ATTR(file_alloc, MTHP_STAT_FILE_ALLOC); DEFINE_MTHP_STAT_ATTR(file_fallback, MTHP_STAT_FILE_FALLBACK); DEFINE_MTHP_STAT_ATTR(file_fallback_charge, MTHP_STAT_FILE_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); static struct attribute *stats_attrs[] = { &anon_fault_alloc_attr.attr, @@ -569,6 +572,9 @@ static struct attribute *stats_attrs[] = { &file_alloc_attr.attr, &file_fallback_attr.attr, &file_fallback_charge_attr.attr, + &split_attr.attr, + &split_failed_attr.attr, + &split_deferred_attr.attr, NULL, }; @@ -3068,7 +3074,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, XA_STATE_ORDER(xas, &folio->mapping->i_pages, folio->index, new_order); struct anon_vma *anon_vma = NULL; struct address_space *mapping = NULL; - bool is_thp = folio_test_pmd_mappable(folio); + int order = folio_order(folio); int extra_pins, ret; pgoff_t end; bool is_hzp; @@ -3076,7 +3082,7 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio); VM_BUG_ON_FOLIO(!folio_test_large(folio), folio); - if (new_order >= folio_order(folio)) + if (new_order >= order) return -EINVAL; if (folio_test_anon(folio)) { @@ -3253,8 +3259,9 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list, i_mmap_unlock_read(mapping); out: xas_destroy(&xas); - if (is_thp) + if (order >= HPAGE_PMD_ORDER) count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED); + count_mthp_stat(order, !ret ? MTHP_STAT_SPLIT : MTHP_STAT_SPLIT_FAILED); return ret; } @@ -3278,13 +3285,14 @@ void deferred_split_folio(struct folio *folio) #ifdef CONFIG_MEMCG struct mem_cgroup *memcg = folio_memcg(folio); #endif + int order = folio_order(folio); unsigned long flags; /* * Order 1 folios have no space for a deferred list, but we also * won't waste much memory by not adding them to the deferred list. */ - if (folio_order(folio) <= 1) + if (order <= 1) return; /* @@ -3305,8 +3313,9 @@ void deferred_split_folio(struct folio *folio) spin_lock_irqsave(&ds_queue->split_queue_lock, flags); if (list_empty(&folio->_deferred_list)) { - if (folio_test_pmd_mappable(folio)) + if (order >= HPAGE_PMD_ORDER) count_vm_event(THP_DEFERRED_SPLIT_PAGE); + count_mthp_stat(order, MTHP_STAT_SPLIT_DEFERRED); list_add_tail(&folio->_deferred_list, &ds_queue->split_queue); ds_queue->split_queue_len++; #ifdef CONFIG_MEMCG -- 2.45.2