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From:   Yosry Ahmed <yosryahmed@google.com>
Date:   Mon, 2 Oct 2023 14:46:58 -0700
Message-ID: <CAJD7tkYJwaKgGaDygbDwmdZSBdz8wq4MNarjhge8v9153Yh45w@mail.gmail.com>
Subject: Re: [PATCH 0/5] mm: memcg: subtree stats flushing and thresholds
To:     Andrew Morton <akpm@linux-foundation.org>
Cc:     Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        Muchun Song <muchun.song@linux.dev>,
        Ivan Babrou <ivan@cloudflare.com>, Tejun Heo <tj@kernel.org>,
        =?UTF-8?Q?Michal_Koutn=C3=BD?= <mkoutny@suse.com>,
        Waiman Long <longman@redhat.com>, kernel-team@cloudflare.com,
        Wei Xu <weixugc@google.com>, Greg Thelen <gthelen@google.com>,
        linux-mm@kvack.org, cgroups@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Thu, Sep 21, 2023 at 1:11=E2=80=AFAM Yosry Ahmed <yosryahmed@google.com>=
 wrote:
>
> This series attempts to address shortages in today's approach for memcg
> stats flushing, namely occasionally stale or expensive stat reads. The
> series does so by changing the threshold that we use to decide whether
> to trigger a flush to be per memcg instead of global (patch 3), and then
> changing flushing to be per memcg (i.e. subtree flushes) instead of
> global (patch 5).
>
> Patch 3 & 5 are the core of the series, and they include more details
> and testing results. The rest are either cleanups or prep work.
>
> This series replaces the "memcg: more sophisticated stats flushing"
> series [1], which also replaces another series, in a long list of
> attempts to improve memcg stats flushing. It is not a v2 as it is a
> completely different approach. This is based on collected feedback from
> discussions on lkml in all previous attempts. Hopefully, this is the
> final attempt.
>
> [1]https://lore.kernel.org/lkml/20230913073846.1528938-1-yosryahmed@googl=
e.com/
>
> Yosry Ahmed (5):
>   mm: memcg: change flush_next_time to flush_last_time
>   mm: memcg: move vmstats structs definition above flushing code
>   mm: memcg: make stats flushing threshold per-memcg
>   mm: workingset: move the stats flush into workingset_test_recent()
>   mm: memcg: restore subtree stats flushing
>
>  include/linux/memcontrol.h |   8 +-
>  mm/memcontrol.c            | 269 +++++++++++++++++++++----------------
>  mm/vmscan.c                |   2 +-
>  mm/workingset.c            |  37 +++--
>  4 files changed, 181 insertions(+), 135 deletions(-)
>
> --
> 2.42.0.459.ge4e396fd5e-goog
>

Friendly ping for feedback on this approach :)