memcg: update memcg_test.txt to describe memory thresholds

Decription of sanity check for memory thresholds.

Signed-off-by: Kirill A.  Shutemov <kirill@shutemov.name>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Dan Malek <dan@embeddedalley.com>
Cc: 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>
This commit is contained in:
Kirill A. Shutemov 2010-03-10 15:22:36 -08:00 committed by Linus Torvalds
parent 1d8fd973a4
commit 1e111452d4

View File

@ -396,3 +396,24 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y.
memory.stat of both A and B. memory.stat of both A and B.
See 8.2 of Documentation/cgroups/memory.txt to see what value should be See 8.2 of Documentation/cgroups/memory.txt to see what value should be
written to move_charge_at_immigrate. written to move_charge_at_immigrate.
9.10 Memory thresholds
Memory controler implements memory thresholds using cgroups notification
API. You can use Documentation/cgroups/cgroup_event_listener.c to test
it.
(Shell-A) Create cgroup and run event listener
# mkdir /cgroup/A
# ./cgroup_event_listener /cgroup/A/memory.usage_in_bytes 5M
(Shell-B) Add task to cgroup and try to allocate and free memory
# echo $$ >/cgroup/A/tasks
# a="$(dd if=/dev/zero bs=1M count=10)"
# a=
You will see message from cgroup_event_listener every time you cross
the thresholds.
Use /cgroup/A/memory.memsw.usage_in_bytes to test memsw thresholds.
It's good idea to test root cgroup as well.