From: Eric Dumazet <eric.dumazet@gmail.com>
To: starlight@binnacle.cx
Cc: linux-kernel@vger.kernel.org, netdev <netdev@vger.kernel.org>,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: big picture UDP/IP performance question re 2.6.18 -> 2.6.32
Date: Sat, 01 Oct 2011 21:11:43 +0200 [thread overview]
Message-ID: <1317496303.3802.25.camel@edumazet-laptop> (raw)
In-Reply-To: <6.2.5.6.2.20111001141002.05af4b20@binnacle.cx>
Le samedi 01 octobre 2011 à 14:16 -0400, starlight@binnacle.cx a écrit :
> At 08:44 AM 10/1/2011 +0200, Eric Dumazet wrote:
> >In my experience, I have the exact opposite :
> >performance greatly improved in recent
> >kernels. Unless you compile your kernel to include
> >new features that might reduce performance
> >(namespaces, cgroup, ...)
>
> RH has both of the above turned on in the
> 2.6.32-71.29.1.el6.x86_64 kernel tested.
>
> If these are big negatives to network
> performance, could you list what should
> specifically turned off to maximize
> results? Also a recommendation for
> the best recent kernel for another
> benchmark would be helpful.
>
> Probably can't convince anyone to deploy a
> kernel without commercial support, but if
> an alternate compile fixes performance it
> might be possible to convince RH to support
> the alternative build.
>
2.6.32 has a perf tool, that can really help to spot in a few minutes
hot spots. That would definitely help to further diagnose what could be
the problem in your workload.
A single patch can have huge performance impact, sometime not noticed.
For example, in 2.6.36, AF_UNIX support for pid namespaces dropped
performance a lot [commit 7361c36c5224 (af_unix: Allow credentials to
work across user and pid namespaces)], because of a single atomic
operation, but done on each send() and receive() on a central location.
next prev parent reply other threads:[~2011-10-01 19:11 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-01 18:16 big picture UDP/IP performance question re 2.6.18 -> 2.6.32 starlight
2011-10-01 18:40 ` Willy Tarreau
2011-10-01 19:11 ` Eric Dumazet [this message]
2011-10-01 19:43 ` starlight
-- strict thread matches above, loose matches on Subject: below --
2011-10-07 3:27 starlight
2011-10-07 5:40 ` Eric Dumazet
2011-10-07 6:13 ` starlight
2011-10-07 18:09 ` chetan loke
[not found] ` <CAAsGZS4s1wTWW1j7FRUWW9jqpPUVF3Q46AMa7+njvE1ckX0Snw @mail.gmail.com>
2011-10-07 18:37 ` starlight
2011-10-07 19:27 ` chetan loke
[not found] ` <CAAsGZS4b2F9N3nV3TNu5xG+=2d0L0ncste4xv2vqoVFb1pOxEw @mail.gmail.com>
2011-10-07 19:41 ` starlight
2011-10-07 20:07 ` Ben Hutchings
2011-10-11 16:24 ` Chris Friesen
2011-10-07 2:33 starlight
2011-10-07 2:24 starlight
2011-10-05 6:58 starlight
2011-10-05 8:53 ` Eric Dumazet
[not found] ` <1317804832.2473.25.camel@edumazet-HP-Compaq-6005-Pr o-SFF-PC>
2011-10-05 11:50 ` starlight
2011-10-05 6:11 starlight
2011-10-05 3:35 starlight
2011-10-03 18:02 starlight
2011-10-05 6:53 ` Eric Dumazet
2011-10-03 15:25 starlight
2011-10-03 16:16 ` Eric Dumazet
[not found] ` <1317658588.2442.5.camel@edumazet-HP-Compaq-6005-Pro -SFF-PC>
2011-10-03 16:28 ` starlight
2011-10-04 19:16 ` Christoph Lameter
2011-10-04 19:38 ` Joe Perches
2011-10-04 19:42 ` Christoph Lameter
2011-10-04 19:49 ` Serge Belyshev
2011-10-04 20:03 ` Christoph Lameter
2011-10-04 20:12 ` Serge Belyshev
2011-10-04 22:32 ` Con Kolivas
2011-10-04 19:45 ` starlight
2011-10-05 13:22 ` Peter Zijlstra
2011-10-05 14:26 ` Christoph Lameter
2011-10-05 15:12 ` Andi Kleen
2011-10-05 15:33 ` Peter Zijlstra
2011-10-05 15:12 ` starlight
2011-10-02 5:33 starlight
2011-10-02 7:21 ` Eric Dumazet
2011-10-02 8:03 ` Eric Dumazet
2011-10-02 14:47 ` Stephen Hemminger
2011-10-02 15:06 ` starlight
2011-10-04 19:54 ` Loke, Chetan
2011-10-01 21:13 starlight
[not found] <6.2.5.6.2.20111001012019.05c05b80@flumedata.com>
2011-10-01 6:44 ` Eric Dumazet
2011-10-01 15:56 ` starlight
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