memcgroup: add the max_usage member on the res_counter
This field is the maximal value of the usage one since the counter creation
(or since the latest reset).
To reset this to the usage value simply write anything to the appropriate
cgroup file.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/res_counter.c b/kernel/res_counter.c
index 7058765..d3c61b4 100644
--- a/kernel/res_counter.c
+++ b/kernel/res_counter.c
@@ -28,6 +28,8 @@
}
counter->usage += val;
+ if (counter->usage > counter->max_usage)
+ counter->max_usage = counter->usage;
return 0;
}
@@ -66,6 +68,8 @@
switch (member) {
case RES_USAGE:
return &counter->usage;
+ case RES_MAX_USAGE:
+ return &counter->max_usage;
case RES_LIMIT:
return &counter->limit;
case RES_FAILCNT: