From dcdf11ee144133328664d90836e712d840d047d9 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Mon, 6 Apr 2020 20:04:25 -0700 Subject: mm, shmem: add vmstat for hugepage fallback The existing thp_fault_fallback indicates when thp attempts to allocate a hugepage but fails, or if the hugepage cannot be charged to the mem cgroup hierarchy. Extend this to shmem as well. Adds a new thp_file_fallback to complement thp_file_alloc that gets incremented when a hugepage is attempted to be allocated but fails, or if it cannot be charged to the mem cgroup hierarchy. Additionally, remove the check for CONFIG_TRANSPARENT_HUGE_PAGECACHE from shmem_alloc_hugepage() since it is only called with this configuration option. Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Reviewed-by: Yang Shi Acked-by: Kirill A. Shutemov Cc: Mike Rapoport Cc: Jeremy Cline Cc: Andrea Arcangeli Cc: Mike Kravetz Cc: Michal Hocko Cc: Vlastimil Babka Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2003061421240.7412@chino.kir.corp.google.com Signed-off-by: Linus Torvalds --- mm/shmem.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'mm/shmem.c') diff --git a/mm/shmem.c b/mm/shmem.c index f47347cb30f6..8160d0762bf5 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1472,9 +1472,6 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, pgoff_t hindex; struct page *page; - if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) - return NULL; - hindex = round_down(index, HPAGE_PMD_NR); if (xa_find(&mapping->i_pages, &hindex, hindex + HPAGE_PMD_NR - 1, XA_PRESENT)) @@ -1486,6 +1483,8 @@ static struct page *shmem_alloc_hugepage(gfp_t gfp, shmem_pseudo_vma_destroy(&pvma); if (page) prep_transhuge_page(page); + else + count_vm_event(THP_FILE_FALLBACK); return page; } @@ -1871,8 +1870,11 @@ alloc_nohuge: error = mem_cgroup_try_charge_delay(page, charge_mm, gfp, &memcg, PageTransHuge(page)); - if (error) + if (error) { + if (PageTransHuge(page)) + count_vm_event(THP_FILE_FALLBACK); goto unacct; + } error = shmem_add_to_page_cache(page, mapping, hindex, NULL, gfp & GFP_RECLAIM_MASK); if (error) { -- cgit v1.2.3