]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
memcg: remove PCG_CACHE page_cgroup flag
authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Wed, 21 Mar 2012 23:34:22 +0000 (16:34 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 22 Mar 2012 00:55:01 +0000 (17:55 -0700)
commitb24028572fb69e9dd6de8c359eba2b2c66baa889
tree563594eba40e5fd0b61c36c09705f128a8dfbe40
parentca464d69b19120a826aa2534de2511a6f542edf5
memcg: remove PCG_CACHE page_cgroup flag

We record 'the page is cache' with the PCG_CACHE bit in page_cgroup.
Here, "CACHE" means anonymous user pages (and SwapCache).  This doesn't
include shmem.

Considering callers, at charge/uncharge, the caller should know what the
page is and we don't need to record it by using one bit per page.

This patch removes PCG_CACHE bit and make callers of
mem_cgroup_charge_statistics() to specify what the page is.

About page migration: Mapping of the used page is not touched during migra
tion (see page_remove_rmap) so we can rely on it and push the correct
charge type down to __mem_cgroup_uncharge_common from end_migration for
unused page.  The force flag was misleading was abused for skipping the
needless page_mapped() / PageCgroupMigration() check, as we know the
unused page is no longer mapped and cleared the migration flag just a few
lines up.  But doing the checks is no biggie and it's not worth adding
another flag just to skip them.

[akpm@linux-foundation.org: checkpatch fixes]
[hughd@google.com: fix PageAnon uncharging]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ying Han <yinghan@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/page_cgroup.h
mm/memcontrol.c