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Message-ID: <4c68b650b02b2a49f90cdf3a0084cf31bd6c7979.camel@redhat.com>
Subject: Re: Re: [PATCH net-next v2 3/3] sock: Fix improper heuristic on
 raising memory
From:   Paolo Abeni <pabeni@redhat.com>
To:     Abel Wu <wuyun.abel@bytedance.com>,
        "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Shakeel Butt <shakeelb@google.com>
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Thu, 19 Oct 2023 13:41:48 +0200
In-Reply-To: <c3110f12-5d9f-4907-a712-5a1004ec4fdc@bytedance.com>
References: <20231016132812.63703-1-wuyun.abel@bytedance.com>
         <20231016132812.63703-3-wuyun.abel@bytedance.com>
         <d1271d557adb68b5f77649861faf470f265e9f6b.camel@redhat.com>
         <c3110f12-5d9f-4907-a712-5a1004ec4fdc@bytedance.com>
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On Thu, 2023-10-19 at 19:23 +0800, Abel Wu wrote:
> On 10/19/23 4:53 PM, Paolo Abeni Wrote:
> > On Mon, 2023-10-16 at 21:28 +0800, Abel Wu 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.
> > >=20
> > > 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.
> > >=20
> > > 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.
> > >=20
> > > Fixes: e1aab161e013 ("socket: initial cgroup code.")
> >=20
> > I think it's better to drop this fixes tag. This is a functional change
> > and with such tag on at this point of the cycle, will land soon into
> > every stable tree. That feels not appropriate.
> >=20
> > Please repost without such tag, thanks!
> >=20
> > You can send the change to stables trees later, if needed.
>=20
> OK. Shall I add a Acked-by tag for you?

Let's be formal:

Acked-by: Paolo Abeni <pabeni@redhat.com>

/P