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References: <20231016132812.63703-1-wuyun.abel@bytedance.com> <20231016132812.63703-3-wuyun.abel@bytedance.com>
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From:   Shakeel Butt <shakeelb@google.com>
Date:   Mon, 16 Oct 2023 08:52:48 -0700
Message-ID: <CALvZod6FRH2cp2D2uECeAesGY575+mE_iyFwaXVJMbfk1jvcgQ@mail.gmail.com>
Subject: Re: [PATCH net-next v2 3/3] sock: Fix improper heuristic on raising memory
To:     Abel Wu <wuyun.abel@bytedance.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Mon, Oct 16, 2023 at 6:28=E2=80=AFAM Abel Wu <wuyun.abel@bytedance.com> =
wrote:
>
> Before sockets became aware of net-memcg's memory pressure since
> commit e1aab161e013 ("socket: initial cgroup code."), the memory
> usage would be granted to raise if below average even when under
> protocol's pressure. This provides fairness among the sockets of
> same protocol.
>
> That commit changes this because the heuristic will also be
> effective when only memcg is under pressure which makes no sense.
> Fix this by reverting to the behavior before that commit.
>
> After this fix, __sk_mem_raise_allocated() no longer considers
> memcg's pressure. As memcgs are isolated from each other w.r.t.
> memory accounting, consuming one's budget won't affect others.
> So except the places where buffer sizes are needed to be tuned,
> allow workloads to use the memory they are provisioned.
>
> Fixes: e1aab161e013 ("socket: initial cgroup code.")
> Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>

Acked-by: Shakeel Butt <shakeelb@google.com>