From: Cong Wang <amwang@redhat.com>
To: Eric Dumazet <erdnetdev@gmail.com>
Cc: netdev@vger.kernel.org, Ben Greear <greearb@candelatech.com>,
David Miller <davem@davemloft.net>,
Stephen Hemminger <shemminger@vyatta.com>,
Rick Jones <rick.jones2@hp.com>, Thomas Graf <tgraf@redhat.com>
Subject: Re: TCP delayed ACK heuristic
Date: Wed, 19 Dec 2012 14:54:39 +0800 [thread overview]
Message-ID: <1355900079.6665.13.camel@cr0> (raw)
In-Reply-To: <1355848224.9380.30.camel@edumazet-glaptop>
On Tue, 2012-12-18 at 08:30 -0800, Eric Dumazet wrote:
>
>
> ACKS might also be delayed because of bidirectional traffic, and is more
> controlled by the application response time. TCP stack can not easily
> estimate it.
So we still need a knob?
>
> If you focus on bulk receive, LRO/GRO should already lower number of
> ACKS to an acceptable level and without major disruption.
Indeed.
>
> Stretch acks are not only the receiver concern, there are issues for the
> sender that you cannot always control/change.
>
> I recommend reading RFC2525 2.13
>
Very helpful information!
On the sender's side, it needs to "notify" the receiver not to send
stretch acks when it is in slow-start. But I think the receiver can
detect slow-start too on its own side (based one the window size?).
Thanks!
next prev parent reply other threads:[~2012-12-19 6:54 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <270756364.27707018.1355842632348.JavaMail.root@redhat.com>
2012-12-18 15:11 ` TCP delayed ACK heuristic Cong Wang
2012-12-18 16:30 ` Eric Dumazet
2012-12-19 6:54 ` Cong Wang [this message]
2012-12-18 16:39 ` David Laight
2012-12-18 17:54 ` Rick Jones
2012-12-19 9:52 ` David Laight
2012-12-19 7:00 ` Cong Wang
2012-12-19 18:39 ` Rick Jones
2012-12-19 20:59 ` David Miller
2012-12-20 3:23 ` Cong Wang
2012-12-20 9:57 ` David Laight
2012-12-20 12:41 ` Cong Wang
2012-12-19 23:08 ` Eric Dumazet
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