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/memory.c | 30 ++++++++++-------------------- 1 file changed, 10 insertions(+), 20 deletions(-) (limited to 'mm/memory.c') diff --git a/mm/memory.c b/mm/memory.c index c387430f06c3..f7026c035940 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -832,10 +832,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, } else if (is_migration_entry(entry)) { page = migration_entry_to_page(entry); - if (PageAnon(page)) - rss[MM_ANONPAGES]++; - else - rss[MM_FILEPAGES]++; + rss[mm_counter(page)]++; if (is_write_migration_entry(entry) && is_cow_mapping(vm_flags)) { @@ -874,10 +871,7 @@ copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, if (page) { get_page(page); page_dup_rmap(page); - if (PageAnon(page)) - rss[MM_ANONPAGES]++; - else - rss[MM_FILEPAGES]++; + rss[mm_counter(page)]++; } out_set_pte: @@ -1113,9 +1107,8 @@ again: tlb_remove_tlb_entry(tlb, pte, addr); if (unlikely(!page)) continue; - if (PageAnon(page)) - rss[MM_ANONPAGES]--; - else { + + if (!PageAnon(page)) { if (pte_dirty(ptent)) { force_flush = 1; set_page_dirty(page); @@ -1123,8 +1116,8 @@ again: if (pte_young(ptent) && likely(!(vma->vm_flags & VM_SEQ_READ))) mark_page_accessed(page); - rss[MM_FILEPAGES]--; } + rss[mm_counter(page)]--; page_remove_rmap(page); if (unlikely(page_mapcount(page) < 0)) print_bad_pte(vma, addr, ptent, page); @@ -1146,11 +1139,7 @@ again: struct page *page; page = migration_entry_to_page(entry); - - if (PageAnon(page)) - rss[MM_ANONPAGES]--; - else - rss[MM_FILEPAGES]--; + rss[mm_counter(page)]--; } if (unlikely(!free_swap_and_cache(entry))) print_bad_pte(vma, addr, ptent, NULL); @@ -1460,7 +1449,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, /* Ok, finally just insert the thing.. */ get_page(page); - inc_mm_counter_fast(mm, MM_FILEPAGES); + inc_mm_counter_fast(mm, mm_counter_file(page)); page_add_file_rmap(page); set_pte_at(mm, addr, pte, mk_pte(page, prot)); @@ -2097,7 +2086,8 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma, if (likely(pte_same(*page_table, orig_pte))) { if (old_page) { if (!PageAnon(old_page)) { - dec_mm_counter_fast(mm, MM_FILEPAGES); + dec_mm_counter_fast(mm, + mm_counter_file(old_page)); inc_mm_counter_fast(mm, MM_ANONPAGES); } } else { @@ -2820,7 +2810,7 @@ void do_set_pte(struct vm_area_struct *vma, unsigned long address, inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES); page_add_new_anon_rmap(page, vma, address); } else { - inc_mm_counter_fast(vma->vm_mm, MM_FILEPAGES); + inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page)); page_add_file_rmap(page); } set_pte_at(vma->vm_mm, address, pte, entry); -- cgit v1.2.3-55-g7522