From eca56ff906bdd0239485e8b47154a6e73dd9a2f3 Mon Sep 17 00:00:00 2001 From: Jerome Marchand Date: Thu, 14 Jan 2016 15:19:26 -0800 Subject: mm, shmem: add internal shmem resident memory accounting Currently looking at /proc//status or statm, there is no way to distinguish shmem pages from pages mapped to a regular file (shmem pages are mapped to /dev/zero), even though their implication in actual memory use is quite different. The internal accounting currently counts shmem pages together with regular files. As a preparation to extend the userspace interfaces, this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for shmem pages separately from MM_FILEPAGES. The next patch will expose it to userspace - this patch doesn't change the exported values yet, by adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was used before. The only user-visible change after this patch is the OOM killer message that separates the reported "shmem-rss" from "file-rss". [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand Signed-off-by: Vlastimil Babka Acked-by: Konstantin Khlebnikov Acked-by: Michal Hocko Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/rmap.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) (limited to 'mm/rmap.c') diff --git a/mm/rmap.c b/mm/rmap.c index 3c3f1d21f075..622756c16ac8 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1364,10 +1364,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, if (PageHuge(page)) { hugetlb_count_sub(1 << compound_order(page), mm); } else { - if (PageAnon(page)) - dec_mm_counter(mm, MM_ANONPAGES); - else - dec_mm_counter(mm, MM_FILEPAGES); + dec_mm_counter(mm, mm_counter(page)); } set_pte_at(mm, address, pte, swp_entry_to_pte(make_hwpoison_entry(page))); @@ -1377,10 +1374,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, * interest anymore. Simply discard the pte, vmscan * will take care of the rest. */ - if (PageAnon(page)) - dec_mm_counter(mm, MM_ANONPAGES); - else - dec_mm_counter(mm, MM_FILEPAGES); + dec_mm_counter(mm, mm_counter(page)); } else if (IS_ENABLED(CONFIG_MIGRATION) && (flags & TTU_MIGRATION)) { swp_entry_t entry; pte_t swp_pte; @@ -1420,7 +1414,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, swp_pte = pte_swp_mksoft_dirty(swp_pte); set_pte_at(mm, address, pte, swp_pte); } else - dec_mm_counter(mm, MM_FILEPAGES); + dec_mm_counter(mm, mm_counter_file(page)); page_remove_rmap(page); page_cache_release(page); -- cgit v1.2.3