Re: [PATCH net-next v2 3/3] sock: Fix improper heuristic on raising memory

From: Shakeel Butt
Date: Mon Oct 16 2023 - 11:53:04 EST


On Mon, Oct 16, 2023 at 6:28 AM Abel Wu <wuyun.abel@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>

Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>