From: Pavel Emelyanov This is a very common requirement from people using the resource accounting facilities (not only memcgroup but also OpenVZ beancounters). They want to put the cgroup in an initial state without re-creating it. For example after re-configuring a group people want to observe how this new configuration fits the group needs without saving the previous failcnt value. Merge two resets into one mem_cgroup_reset() function to demonstrate how multiplexing work. Besides, I have plans to move the files, that correspond to res_counter to the res_counter.c file and somehow "import" them into controller. I don't know how to make it gracefully yet, but merging resets of max_usage and failcnt in one function will be there for sure. Signed-off-by: Pavel Emelyanov Acked-by: KAMEZAWA Hiroyuki Cc: Balbir Singh Cc: Paul Menage Signed-off-by: Andrew Morton --- include/linux/res_counter.h | 8 ++++++++ mm/memcontrol.c | 14 +++++++++++--- 2 files changed, 19 insertions(+), 3 deletions(-) diff -puN include/linux/res_counter.h~memcgroup-implement-failcounter-reset include/linux/res_counter.h --- a/include/linux/res_counter.h~memcgroup-implement-failcounter-reset +++ a/include/linux/res_counter.h @@ -143,4 +143,12 @@ static inline void res_counter_reset_max spin_unlock_irqrestore(&cnt->lock, flags); } +static inline void res_counter_reset_failcnt(struct res_counter *cnt) +{ + unsigned long flags; + + spin_lock_irqsave(&cnt->lock, flags); + cnt->failcnt = 0; + spin_unlock_irqrestore(&cnt->lock, flags); +} #endif diff -puN mm/memcontrol.c~memcgroup-implement-failcounter-reset mm/memcontrol.c --- a/mm/memcontrol.c~memcgroup-implement-failcounter-reset +++ a/mm/memcontrol.c @@ -857,12 +857,19 @@ static ssize_t mem_cgroup_write(struct c mem_cgroup_write_strategy); } -static int mem_cgroup_max_reset(struct cgroup *cont, unsigned int event) +static int mem_cgroup_reset(struct cgroup *cont, unsigned int event) { struct mem_cgroup *mem; mem = mem_cgroup_from_cont(cont); - res_counter_reset_max(&mem->res); + switch (event) { + case RES_MAX_USAGE: + res_counter_reset_max(&mem->res); + break; + case RES_FAILCNT: + res_counter_reset_failcnt(&mem->res); + break; + } return 0; } @@ -916,7 +923,7 @@ static struct cftype mem_cgroup_files[] { .name = "max_usage_in_bytes", .private = RES_MAX_USAGE, - .trigger = mem_cgroup_max_reset, + .trigger = mem_cgroup_reset, .read_u64 = mem_cgroup_read, }, { @@ -928,6 +935,7 @@ static struct cftype mem_cgroup_files[] { .name = "failcnt", .private = RES_FAILCNT, + .trigger = mem_cgroup_reset, .read_u64 = mem_cgroup_read, }, { _