From: Willy Tarreau <w@1wt.eu>
To: David Laight <David.Laight@ACULAB.COM>
Cc: Arnaud Ebalard <arno@natisbad.org>,
Cong Wang <xiyou.wangcong@gmail.com>,
edumazet@google.com, linux-arm-kernel@lists.infradead.org,
netdev@vger.kernel.org,
Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Subject: Re: [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s
Date: Mon, 18 Nov 2013 11:52:58 +0100 [thread overview]
Message-ID: <20131118105258.GB26398@1wt.eu> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B742A@saturn3.aculab.com>
On Mon, Nov 18, 2013 at 10:09:53AM -0000, David Laight wrote:
> > So it is fairly possible that in your case you can't fill the link if you
> > consume too many descriptors. For example, if your server uses TCP_NODELAY
> > and sends incomplete segments (which is quite common), it's very easy to
> > run out of descriptors before the link is full.
>
> Or you have a significant number of active tcp connections.
>
> Even if there were no requirement to free the skb quickly you still
> need to take a 'tx done' interrupt when the link is transmit rate limited.
> There are scenarios when there is no receive traffic - eg asymmetric
> routing, but testable with netperf UDP transmits.
Yes absolutely, but I was talking about the current situation that Arnaud
is facing and which I could reproduce with a large window.
Willy
next prev parent reply other threads:[~2013-11-18 10:53 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-10 13:53 [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s Arnaud Ebalard
2013-11-12 6:48 ` Cong Wang
2013-11-12 7:56 ` Arnaud Ebalard
2013-11-12 8:36 ` Willy Tarreau
2013-11-12 9:14 ` Arnaud Ebalard
2013-11-12 10:01 ` Willy Tarreau
2013-11-12 15:34 ` Arnaud Ebalard
2013-11-13 7:22 ` Willy Tarreau
2013-11-17 14:19 ` Willy Tarreau
2013-11-17 17:41 ` Eric Dumazet
2013-11-19 6:44 ` Arnaud Ebalard
2013-11-19 13:53 ` Eric Dumazet
2013-11-19 17:43 ` Willy Tarreau
2013-11-19 18:31 ` Eric Dumazet
2013-11-19 18:41 ` Willy Tarreau
2013-11-19 23:53 ` Arnaud Ebalard
2013-11-20 0:08 ` Eric Dumazet
2013-11-20 0:35 ` Willy Tarreau
2013-11-20 0:43 ` Eric Dumazet
2013-11-20 0:52 ` Willy Tarreau
2013-11-20 8:50 ` Thomas Petazzoni
2013-11-20 19:11 ` Willy Tarreau
2013-11-20 19:26 ` Arnaud Ebalard
2013-11-20 21:28 ` Arnaud Ebalard
2013-11-20 21:54 ` Willy Tarreau
2013-11-21 0:44 ` Willy Tarreau
2013-11-21 18:38 ` ARM network performance and dma_mask (was: [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s) Willy Tarreau
2013-11-21 19:04 ` Thomas Petazzoni
2013-11-21 21:51 ` Willy Tarreau
2013-11-21 22:01 ` ARM network performance and dma_mask Rob Herring
2013-11-21 22:13 ` Willy Tarreau
2013-11-21 21:51 ` [BUG,REGRESSION?] 3.11.6+,3.12: GbE iface rate drops to few KB/s Arnaud Ebalard
2013-11-21 21:52 ` Willy Tarreau
2013-11-21 22:00 ` Eric Dumazet
2013-11-21 22:55 ` Arnaud Ebalard
2013-11-21 23:23 ` Rick Jones
2013-11-20 17:12 ` Willy Tarreau
2013-11-20 17:30 ` Eric Dumazet
2013-11-20 17:38 ` Willy Tarreau
2013-11-20 18:52 ` David Miller
2013-11-20 17:34 ` Willy Tarreau
2013-11-20 17:40 ` Eric Dumazet
2013-11-20 18:15 ` Willy Tarreau
2013-11-20 18:21 ` Eric Dumazet
2013-11-20 18:29 ` Willy Tarreau
2013-11-20 19:22 ` Arnaud Ebalard
2013-11-18 10:09 ` David Laight
2013-11-18 10:52 ` Willy Tarreau [this message]
2013-11-18 10:26 ` Thomas Petazzoni
2013-11-18 10:44 ` Simon Guinot
2013-11-18 16:54 ` Stephen Hemminger
2013-11-18 17:13 ` Eric Dumazet
2013-11-18 10:51 ` Willy Tarreau
2013-11-18 17:58 ` Florian Fainelli
2013-11-12 14:39 ` [PATCH] tcp: tsq: restore minimal amount of queueing Eric Dumazet
2013-11-12 15:24 ` Sujith Manoharan
2013-11-13 14:06 ` Eric Dumazet
2013-11-13 14:32 ` [PATCH v2] " Eric Dumazet
2013-11-13 21:18 ` Arnaud Ebalard
2013-11-13 21:59 ` Holger Hoffstaette
2013-11-13 23:40 ` Eric Dumazet
2013-11-13 23:52 ` Holger Hoffstaette
2013-11-17 23:15 ` Francois Romieu
2013-11-18 16:26 ` Holger Hoffstätte
2013-11-18 16:47 ` Eric Dumazet
2013-11-13 22:41 ` Eric Dumazet
2013-11-14 21:26 ` David Miller
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