From: Eric Dumazet <firstname.lastname@example.org> To: Rick Jones <email@example.com> Cc: David Miller <firstname.lastname@example.org>, netdev <email@example.com>, Yuchung Cheng <firstname.lastname@example.org>, Neal Cardwell <email@example.com>, Michael Kerrisk <firstname.lastname@example.org> Subject: Re: [PATCH v3 net-next 2/2] tcp: TCP_NOTSENT_LOWAT socket option Date: Tue, 23 Jul 2013 10:18:02 -0700 [thread overview] Message-ID: <1374599882.3449.46.camel@edumazet-glaptop> (raw) In-Reply-To: <51EEAD54.email@example.com> On Tue, 2013-07-23 at 09:20 -0700, Rick Jones wrote: > Isn't this change really just trying to paper-over the autotuning's > over-growing of the socket buffers? Or are you considering it an > extension of the auto-tuning heuristics? > > If your 20Gbit test setup needed only 256KB socket buffers (figure > pulled form the ether) to get to 17 Gbit/s, isn't the autotuning's > growing them to several MB a bug in the autotuning? As long as we limit the number of unsent bytes, there is no longer an over provisioning problem. TCP stack will be able to use the large windows if _needed_ by current network conditions, receiver (in)ability to drain the data, and if allowed by congestion control constraints. If now you are complaining that TCP congestion controls are bad, thats a completely different story, and this patch does not claim to solve this.
next prev parent reply other threads:[~2013-07-23 17:18 UTC|newest] Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top 2013-07-23 3:27 Eric Dumazet 2013-07-23 3:52 ` Hannes Frederic Sowa 2013-07-23 15:26 ` Rick Jones 2013-07-23 15:44 ` Eric Dumazet 2013-07-23 16:20 ` Rick Jones 2013-07-23 16:48 ` Eric Dumazet 2013-07-23 17:18 ` Eric Dumazet [this message] 2013-07-23 18:24 ` Yuchung Cheng 2013-07-25 0:55 ` David Miller 2013-07-23 19:19 Neal Cardwell 2013-07-23 19:28 Neal Cardwell
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