From: Neal Cardwell <ncardwell@google.com>
To: Eric Dumazet <edumazet@google.com>
Cc: David Miller <davem@davemloft.net>,
Netdev <netdev@vger.kernel.org>,
jean-louis@dupond.be, Yuchung Cheng <ycheng@google.com>,
Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH net-next 2/3] tcp: implement coalescing on backlog queue
Date: Thu, 22 Nov 2018 13:01:36 -0500 [thread overview]
Message-ID: <CADVnQykiiFz5H3J_vrCXHQ_FQ+Fg3qCZKoynsc_fdY_PcTx8cg@mail.gmail.com> (raw)
In-Reply-To: <20181121175240.6075-3-edumazet@google.com>
On Wed, Nov 21, 2018 at 12:52 PM Eric Dumazet <edumazet@google.com> wrote:
>
> In case GRO is not as efficient as it should be or disabled,
> we might have a user thread trapped in __release_sock() while
> softirq handler flood packets up to the point we have to drop.
>
> This patch balances work done from user thread and softirq,
> to give more chances to __release_sock() to complete its work.
>
> This also helps if we receive many ACK packets, since GRO
> does not aggregate them.
Would this coalesce duplicate incoming ACK packets? Is there a risk
that this would eliminate incoming dupacks needed for fast recovery in
non-SACK connections? Perhaps pure ACKs should only be coalesced if
the ACK field is different?
neal
next prev parent reply other threads:[~2018-11-23 4:42 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-21 17:52 [PATCH net-next 0/3] tcp: take a bit more care of backlog stress Eric Dumazet
2018-11-21 17:52 ` [PATCH net-next 1/3] tcp: remove hdrlen argument from tcp_queue_rcv() Eric Dumazet
2018-11-21 22:41 ` Yuchung Cheng
2018-11-21 17:52 ` [PATCH net-next 2/3] tcp: implement coalescing on backlog queue Eric Dumazet
2018-11-21 22:31 ` Yuchung Cheng
2018-11-21 22:40 ` Eric Dumazet
2018-11-22 16:34 ` Yuchung Cheng
2018-11-22 18:01 ` Neal Cardwell [this message]
2018-11-22 18:16 ` Eric Dumazet
2018-11-22 18:21 ` Eric Dumazet
2018-11-21 17:52 ` [PATCH net-next 3/3] tcp: implement head drops in " Eric Dumazet
2018-11-21 22:40 ` Yuchung Cheng
2018-11-21 22:47 ` Eric Dumazet
2018-11-21 23:46 ` Yuchung Cheng
2018-11-21 23:52 ` Eric Dumazet
2018-11-22 0:18 ` Eric Dumazet
2018-11-22 0:54 ` Yuchung Cheng
2018-11-22 1:01 ` Eric Dumazet
2018-11-23 19:25 ` [PATCH net-next 0/3] tcp: take a bit more care of backlog stress David Miller
2018-11-23 19:27 ` Eric Dumazet
2019-04-07 21:28 [PATCH net-next 2/3] tcp: implement coalescing on backlog queue richard.purdie
2019-04-24 14:51 ` Bruno Prémont
2019-04-24 15:47 ` Eric Dumazet
2019-04-25 7:55 ` Bruno Prémont
2019-04-25 13:13 ` Bruno Prémont
2019-04-25 13:30 ` Eric Dumazet
2019-04-25 14:16 ` Bruno Prémont
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