mm, shmem: add internal shmem resident memory accounting
authorJerome Marchand <jmarchan@redhat.com>
Thu, 14 Jan 2016 23:19:26 +0000 (15:19 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 15 Jan 2016 00:00:49 +0000 (16:00 -0800)
commiteca56ff906bdd0239485e8b47154a6e73dd9a2f3
tree2eca71e20820247d4e81243a920db3a138f558db
parent48131e03ca4ed71d73fbe55c311a258c6fa2a090
mm, shmem: add internal shmem resident memory accounting

Currently looking at /proc/<pid>/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 <jmarchan@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/s390/mm/pgtable.c
fs/proc/task_mmu.c
include/linux/mm.h
include/linux/mm_types.h
kernel/events/uprobes.c
mm/memory.c
mm/oom_kill.c
mm/rmap.c