From: Eric Dumazet <eric.dumazet@gmail.com>
To: Yuchung Cheng <ycheng@google.com>, davem@davemloft.net
Cc: netdev@vger.kernel.org, edumazet@google.com,
ncardwell@google.com, brakmo@fb.com, ysseung@google.com
Subject: Re: [PATCH net 3/3] tcp: do not delay ACK in DCTCP upon CE status change
Date: Wed, 18 Jul 2018 14:44:05 -0700 [thread overview]
Message-ID: <70a585a2-c276-73f7-591e-ae4eb883a075@gmail.com> (raw)
In-Reply-To: <20180718205636.210731-4-ycheng@google.com>
On 07/18/2018 01:56 PM, Yuchung Cheng wrote:
> Per DCTCP RFC8257 (Section 3.2) the ACK reflecting the CE status change
> has to be sent immediately so the sender can respond quickly:
>
> """ When receiving packets, the CE codepoint MUST be processed as follows:
>
> 1. If the CE codepoint is set and DCTCP.CE is false, set DCTCP.CE to
> true and send an immediate ACK.
>
> 2. If the CE codepoint is not set and DCTCP.CE is true, set DCTCP.CE
> to false and send an immediate ACK.
> """
>
> Previously DCTCP implementation may continue to delay the ACK. This
> patch fixes that to implement the RFC by forcing an immediate ACK.
Oh well, more ACK packets ;)
Signed-off-by: Eric Dumazet <edumazet@google.com>
next prev parent reply other threads:[~2018-07-18 22:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 20:56 [PATCH net 0/3] fix DCTCP ECE Ack series Yuchung Cheng
2018-07-18 20:56 ` [PATCH net 1/3] tcp: helpers to send special DCTCP ack Yuchung Cheng
2018-07-18 21:42 ` Eric Dumazet
2018-07-18 20:56 ` [PATCH net 2/3] tcp: do not cancel delay-AcK on DCTCP special ACK Yuchung Cheng
2018-07-18 21:42 ` Eric Dumazet
2018-07-18 20:56 ` [PATCH net 3/3] tcp: do not delay ACK in DCTCP upon CE status change Yuchung Cheng
2018-07-18 21:44 ` Eric Dumazet [this message]
2018-07-20 21:32 ` [PATCH net 0/3] fix DCTCP ECE Ack series David Miller
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