Re: [PATCH 1/2] mm: Rename ambiguously named memory.stat counters and functions

[Roman Gushchin <guro@fb.com>]

On Wed, Jan 23, 2019 at 05:30:49PM -0500, Chris Down wrote:
> I spent literally an hour trying to work out why an earlier version of
> my memory.events aggregation code doesn't work properly, only to find
> out I was calling memcg->events instead of memcg->memory_events, which
> is fairly confusing.
> 
> This naming seems in need of reworking, so make it harder to do the
> wrong thing by using vmevents instead of events, which makes it more
> clear that these are vm counters rather than memcg-specific counters.
> 
> There are also a few other inconsistent names in both the percpu and
> aggregated structs, so these are all cleaned up to be more coherent and
> easy to understand.
> 
> This commit contains code cleanup only: there are no logic changes.
> 
> Signed-off-by: Chris Down <chris@chrisdown.name>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> To: Andrew Morton <akpm@linux-foundation.org>

s/To/Cc

> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: Roman Gushchin <guro@fb.com>
> Cc: Dennis Zhou <dennis@kernel.org>
> Cc: linux-kernel@vger.kernel.org
> Cc: cgroups@vger.kernel.org
> Cc: linux-mm@kvack.org
> Cc: kernel-team@fb.com
> ---
> include/linux/memcontrol.h |  24 +++----
> mm/memcontrol.c            | 137 +++++++++++++++++++------------------
> 2 files changed, 82 insertions(+), 79 deletions(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index b0eb29ea0d9c..380a212a8c52 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -94,8 +94,8 @@ enum mem_cgroup_events_target {
> 	MEM_CGROUP_NTARGETS,
> };
> 
> -struct mem_cgroup_stat_cpu {
> -	long count[MEMCG_NR_STAT];
> +struct memcg_vmstats_percpu {
> +	long stat[MEMCG_NR_STAT];

I'd personally go with memcg_vmstat_percpu. Not insisting,
but you end up using both vmstat and vmstats, which isn't very
consistent.

Other than that looks good to me. Please, feel free to add
Acked-by: Roman Gushchin <guro@fb.com>

Thanks!