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Subject: Re: [PATCH v2 net-next] inet: do not set backlog if listen fails
To:     Yafang Shao <laoar.shao@gmail.com>, edumazet@google.com,
        davem@davemloft.net
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org
References: <1538919405-3093-1-git-send-email-laoar.shao@gmail.com>
From:   Eric Dumazet <eric.dumazet@gmail.com>
Message-ID: <0652963b-90ac-06a7-3a35-50a307465cf9@gmail.com>
Date:   Sun, 7 Oct 2018 10:39:21 -0700
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On 10/07/2018 06:36 AM, Yafang Shao wrote:
> We don't need to set the backlog if listen fails.
> The sk_max_ack_backlog will be set in the caller inet_listen() and
> dccp_listen_start() if inet_csk_listen_start() return without error.
> So just remove this line to avoid this unnecessary operation.
> 
> Regarding sk_ack_backlog, we have to set it before a TCP/DCCP socket is
> ready to accept new flows to avoid race, because dccp and tcp have lockless
> listeners
>

Really could you not add irrelevant stuff in the changelog ?

This patch simply removes one redundant setting, you do not have to explain
about dccp/tcp being lockless and that sk_ack_backlog is not touched by this patch.

Also the title is misleading, since we will still set the backlog even if the listen
fails.

If you really want sk_max_ack_backlog being not changed if listen() fails,
then I am afraid you will need to submit a different patch.