Re: [RFC][-mm] [2/2] Simple stats for memory resource controller

[Balbir Singh <balbir@linux.vnet.ibm.com>]

Balaji Rao wrote:
> This patch implements trivial statistics for the memory resource controller.
> 
> Signed-off-by: Balaji Rao <balajirrao@gmail.com>
> CC: Balbir Singh <balbir@linux.vnet.ibm.com>
> CC: Dhaval Giani <dhaval@linux.vnet.ibm.com>
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index a860765..ca98b21 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -47,6 +47,8 @@ enum mem_cgroup_stat_index {
>  	 */
>  	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */
>  	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as rss */
> +	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */
> +	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */
> 
>  	MEM_CGROUP_STAT_NSTATS,
>  };
> @@ -198,6 +200,13 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem, int flags,
>  		__mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_CACHE, val);
>  	else
>  		__mem_cgroup_stat_add_safe(stat, MEM_CGROUP_STAT_RSS, val);
> +
> +	if (charge)
> +		__mem_cgroup_stat_add_safe(stat,
> +				MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
> +	else
> +		__mem_cgroup_stat_add_safe(stat,
> +				MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
>  }
> 
>  static struct mem_cgroup_per_zone *
> @@ -897,6 +906,8 @@ static const struct mem_cgroup_stat_desc {
>  } mem_cgroup_stat_desc[] = {
>  	[MEM_CGROUP_STAT_CACHE] = { "cache", PAGE_SIZE, },
>  	[MEM_CGROUP_STAT_RSS] = { "rss", PAGE_SIZE, },
> +	[MEM_CGROUP_STAT_PGPGIN_COUNT] = {"pgpgin", 1, },
> +	[MEM_CGROUP_STAT_PGPGOUT_COUNT] = {"pgpgout", 1, },
>  };
> 
>  static int mem_control_stat_show(struct cgroup *cont, struct cftype *cft,
> 

Looks good to me. I wonder if pgpin/pggout per second will be a useful metric,
to see how fast things are changing within the cgroup.

Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>

Let me test this patch right away.

-- 
	Warm Regards,
	Balbir Singh
	Linux Technology Center
	IBM, ISTL