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 --- include/linux/mm.h | 18 +++++++++++++++++- include/linux/mm_types.h | 7 ++++--- 2 files changed, 21 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index 00bad7793788..a8ab1fc0e9bc 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1361,10 +1361,26 @@ static inline void dec_mm_counter(struct mm_struct *mm, int member) atomic_long_dec(&mm->rss_stat.count[member]); } +/* Optimized variant when page is already known not to be PageAnon */ +static inline int mm_counter_file(struct page *page) +{ + if (PageSwapBacked(page)) + return MM_SHMEMPAGES; + return MM_FILEPAGES; +} + +static inline int mm_counter(struct page *page) +{ + if (PageAnon(page)) + return MM_ANONPAGES; + return mm_counter_file(page); +} + static inline unsigned long get_mm_rss(struct mm_struct *mm) { return get_mm_counter(mm, MM_FILEPAGES) + - get_mm_counter(mm, MM_ANONPAGES); + get_mm_counter(mm, MM_ANONPAGES) + + get_mm_counter(mm, MM_SHMEMPAGES); } static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index f8d1492a114f..207890be93c8 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -369,9 +369,10 @@ struct core_state { }; enum { - MM_FILEPAGES, - MM_ANONPAGES, - MM_SWAPENTS, + MM_FILEPAGES, /* Resident file mapping pages */ + MM_ANONPAGES, /* Resident anonymous pages */ + MM_SWAPENTS, /* Anonymous swap entries */ + MM_SHMEMPAGES, /* Resident shared memory pages */ NR_MM_COUNTERS }; -- cgit v1.2.3