From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Christoph Lameter <cl@gentwo.org>
Cc: starlight@binnacle.cx, Eric Dumazet <eric.dumazet@gmail.com>,
linux-kernel@vger.kernel.org, netdev <netdev@vger.kernel.org>,
Willy Tarreau <w@1wt.eu>, Ingo Molnar <mingo@elte.hu>
Subject: Re: big picture UDP/IP performance question re 2.6.18 -> 2.6.32
Date: Wed, 05 Oct 2011 15:22:22 +0200 [thread overview]
Message-ID: <1317820942.6766.26.camel@twins> (raw)
In-Reply-To: <alpine.DEB.2.00.1110041358500.12199@router.home>
On Tue, 2011-10-04 at 14:16 -0500, Christoph Lameter wrote:
>
> We had similar experiences. Basically latency constantly gets screwed up
> by the new fancy features being added to the scheduler and network
> subsystem (most notorious is the new "fair" scheduler, 2.6.23 made a big
> step down). The kernel has a fairly constant regression in terms of
> latency release after release. Only the new and more efficient processors
> periodically provide some compensation (and some isolated patches to
> actually improve things get in but these are usually watered down one or
> two releases after those improvements have been made).
I suppose all this testing and feedback we receive from you really helps
us keep the performance levels you want.. Oh wait, that's 0.
Clearly none of the tests being ran on a regular basis, by for instance
the Intel regression team, covers your needs. Start by fixing that.
Also, for latency, we've got ftrace and a latencytracer, provide traces
that illustrate your fail.
next prev parent reply other threads:[~2011-10-05 13:22 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-03 15:25 big picture UDP/IP performance question re 2.6.18 -> 2.6.32 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 [this message]
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
-- 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
2011-10-02 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
2011-10-01 18:16 starlight
2011-10-01 18:40 ` Willy Tarreau
2011-10-01 19:11 ` Eric Dumazet
2011-10-01 19:43 ` 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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