linux/include
Ying Han 0ae5e89c60 memcg: count the soft_limit reclaim in global background reclaim
The global kswapd scans per-zone LRU and reclaims pages regardless of the
cgroup. It breaks memory isolation since one cgroup can end up reclaiming
pages from another cgroup. Instead we should rely on memcg-aware target
reclaim including per-memcg kswapd and soft_limit hierarchical reclaim under
memory pressure.

In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU. However, the return value is ignored. This patch is the first
step to skip shrink_zone() if soft_limit reclaim does enough work.

This is part of the effort which tries to reduce reclaiming pages in global
LRU in memcg. The per-memcg background reclaim patchset further enhances the
per-cgroup targetting reclaim, which I should have V4 posted shortly.

Try running multiple memory intensive workloads within seperate memcgs. Watch
the counters of soft_steal in memory.stat.

  $ cat /dev/cgroup/A/memory.stat | grep 'soft'
  soft_steal 240000
  soft_scan 240000
  total_soft_steal 240000
  total_soft_scan 240000

This patch:

In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU.  However, the return value is ignored.

We would like to skip shrink_zone() if soft_limit reclaim does enough
work.  Also, we need to make the memory pressure balanced across per-memcg
zones, like the logic vm-core.  This patch is the first step where we
start with counting the nr_scanned and nr_reclaimed from soft_limit
reclaim into the global scan_control.

Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:35 -07:00
..
acpi
asm-generic Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6 2011-05-25 17:00:17 -07:00
crypto
drm Merge branch 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6 2011-05-24 12:06:40 -07:00
keys
linux memcg: count the soft_limit reclaim in global background reclaim 2011-05-26 17:12:35 -07:00
math-emu
media [media] rc: add locking to fix register/show race 2011-05-20 16:21:22 -03:00
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd 2011-05-25 18:10:16 -07:00
pcmcia pcmcia: Make declaration and uses of struct pcmcia_device_id const 2011-05-06 07:46:15 +02:00
rdma Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband 2011-05-26 12:13:57 -07:00
rxrpc
scsi scsi: remove performance regression due to async queue run 2011-05-17 11:04:44 +02:00
sound Merge branch 'topic/asoc' into for-linus 2011-05-22 10:01:33 +02:00
staging
target
trace Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6 2011-05-26 12:14:41 -07:00
video Merge branches 'common/fbdev' and 'common/fbdev-meram' of master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6 2011-05-24 15:49:57 +09:00
xen Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem 2011-05-26 10:50:56 -07:00
Kbuild