Re: [patch] Documentation: memcg: future proof hierarchical statisticsdocumentation

From: Randy Dunlap
Date: Tue Apr 24 2012 - 16:07:40 EST


On 04/24/2012 12:33 PM, Johannes Weiner wrote:

> The hierarchical versions of per-memcg counters in memory.stat are all
> calculated the same way and are all named total_<counter>.
>
> Documenting the pattern is easier for maintenance than listing each
> counter twice.
>
> Signed-off-by: Johannes Weiner <hannes@xxxxxxxxxxx>
> Acked-by: Michal Hocko <mhocko@xxxxxxx>
> Acked-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> Acked-by: Ying Han <yinghan@xxxxxxxxxx>
> ---
> Documentation/cgroups/memory.txt | 15 ++++-----------
> 1 files changed, 4 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
> index ab34ae5..6a066a2 100644
> --- a/Documentation/cgroups/memory.txt
> +++ b/Documentation/cgroups/memory.txt
> @@ -432,17 +432,10 @@ hierarchical_memory_limit - # of bytes of memory limit with regard to hierarchy
> hierarchical_memsw_limit - # of bytes of memory+swap limit with regard to
> hierarchy under which memory cgroup is.
>
> -total_cache - sum of all children's "cache"
> -total_rss - sum of all children's "rss"
> -total_mapped_file - sum of all children's "cache"
> -total_pgpgin - sum of all children's "pgpgin"
> -total_pgpgout - sum of all children's "pgpgout"
> -total_swap - sum of all children's "swap"
> -total_inactive_anon - sum of all children's "inactive_anon"
> -total_active_anon - sum of all children's "active_anon"
> -total_inactive_file - sum of all children's "inactive_file"
> -total_active_file - sum of all children's "active_file"
> -total_unevictable - sum of all children's "unevictable"
> +total_<counter> - # hierarchical version of <counter>, which in
> + addition to the cgroup's own value includes the
> + sum of all hierarchical children's values of
> + <counter>, i.e. total_cache

e.g., total_cache

But how is a user or an admin supposed to know what all of the valid
total_<counter> names are? Is the entire list documented anywhere
else other than here (which is being deleted)?


> # The following additional stats are dependent on CONFIG_DEBUG_VM.
>



--
~Randy
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