From 17766dde364813568e4f876517c72bab70838646 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Thu, 12 Sep 2013 15:14:06 -0700 Subject: mm, thp: count thp_fault_fallback anytime thp fault fails Currently, thp_fault_fallback in vmstat only gets incremented if a hugepage allocation fails. If current's memcg hits its limit or the page fault handler returns an error, it is incorrectly accounted as a successful thp_fault_alloc. Count thp_fault_fallback anytime the page fault handler falls back to using regular pages and only count thp_fault_alloc when a hugepage has actually been faulted. Signed-off-by: David Rientjes Cc: Mel Gorman Cc: Andrea Arcangeli Cc: "Kirill A. Shutemov" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/huge_memory.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 243f4cc..f60c4eb 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -820,17 +820,19 @@ int do_huge_pmd_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma, count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } - count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(page, mm, GFP_KERNEL))) { put_page(page); + count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } if (unlikely(__do_huge_pmd_anonymous_page(mm, vma, haddr, pmd, page))) { mem_cgroup_uncharge_page(page); put_page(page); + count_vm_event(THP_FAULT_FALLBACK); return VM_FAULT_FALLBACK; } + count_vm_event(THP_FAULT_ALLOC); return 0; } @@ -1143,7 +1145,6 @@ alloc: new_page = NULL; if (unlikely(!new_page)) { - count_vm_event(THP_FAULT_FALLBACK); if (is_huge_zero_pmd(orig_pmd)) { ret = do_huge_pmd_wp_zero_page_fallback(mm, vma, address, pmd, orig_pmd, haddr); @@ -1154,9 +1155,9 @@ alloc: split_huge_page(page); put_page(page); } + count_vm_event(THP_FAULT_FALLBACK); goto out; } - count_vm_event(THP_FAULT_ALLOC); if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) { put_page(new_page); @@ -1164,10 +1165,13 @@ alloc: split_huge_page(page); put_page(page); } + count_vm_event(THP_FAULT_FALLBACK); ret |= VM_FAULT_OOM; goto out; } + count_vm_event(THP_FAULT_ALLOC); + if (is_huge_zero_pmd(orig_pmd)) clear_huge_page(new_page, haddr, HPAGE_PMD_NR); else -- cgit v1.1