From: John Dykstra <john.dykstra1@gmail.com>
To: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Cc: Benjamin LaHaise <ben.lahaise@neterion.com>,
David Miller <davem@davemloft.net>,
Netdev <netdev@vger.kernel.org>
Subject: Re: lots of cpu time spent in skb_copy_bits() in net-next with small mtu
Date: Tue, 16 Jun 2009 19:20:00 +0000 [thread overview]
Message-ID: <1245180000.7150.6.camel@Maple> (raw)
In-Reply-To: <Pine.LNX.4.64.0906122248450.31625@melkinkari.cs.Helsinki.FI>
On Fri, 2009-06-12 at 22:57 +0300, Ilpo Järvinen wrote:
> On Fri, 12 Jun 2009, Benjamin LaHaise wrote:
>
> > Just a heads up: something in net-next is resulting in lots of cpu time
> > being spent in skb_copy_bits() (called from tcp_collapse()) when an ethernet
> > interface mtu is lowered to 576 on the source and dest machines running
> > netperf. This behaviour does not appear in 2.6.29. I'll try to bisect
> > it this weekend.
>
> I'd suggest somebody goes through DaveM's abstraction patch 915219441d56
> (I'm totally out of time so somebody else has to do it if a timely
> solution is desired)... It was quite messy on those parts and I already
> found one issue from it (2df9001edc3) and wouldn't be too surprised if
> there would be some more lurking around...
I couldn't find anything wrong with tcp_prune_queue() and its helpers as
they appear in today's net-next.
Take that with a grain of salt if you wish--I'm going to go take a
couple grains of aspirin.
-- John
next prev parent reply other threads:[~2009-06-16 19:20 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-12 16:13 lots of cpu time spent in skb_copy_bits() in net-next with small mtu Benjamin LaHaise
2009-06-12 19:57 ` Ilpo Järvinen
2009-06-16 19:20 ` John Dykstra [this message]
2009-06-17 5:46 ` Ilpo Järvinen
2009-06-17 5:53 ` David Miller
2009-06-17 6:57 ` Ilpo Järvinen
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