From: "Zhang, Yanmin" <yanmin_zhang@linux.intel.com>
To: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
Cc: David Miller <davem@davemloft.net>,
cl@linux-foundation.org, Netdev <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: tbench regression on each kernel release from 2.6.22 -> 2.6.28
Date: Mon, 18 Aug 2008 10:05:14 +0800 [thread overview]
Message-ID: <1219025114.25933.6.camel@ymzhang> (raw)
In-Reply-To: <Pine.LNX.4.64.0808121058550.4551@wrl-59.cs.helsinki.fi>
On Tue, 2008-08-12 at 11:13 +0300, Ilpo Järvinen wrote:
> On Mon, 11 Aug 2008, David Miller wrote:
>
> > From: Christoph Lameter <cl@linux-foundation.org>
> > Date: Mon, 11 Aug 2008 13:36:38 -0500
> >
> > > It seems that the network stack becomes slower over time? Here is a list of
> > > tbench results with various kernel versions:
> > >
> > > 2.6.22 3207.77 mb/sec
> > > 2.6.24 3185.66
> > > 2.6.25 2848.83
> > > 2.6.26 2706.09
> > > 2.6.27(rc2) 2571.03
> > >
> > > And linux-next is:
> > >
> > > 2.6.28(l-next) 2568.74
> > >
> > > It shows that there is still have work to be done on linux-next. Too close to
> > > upstream in performance.
> > >
> > > Note the KT event between 2.6.24 and 2.6.25. Why is that?
> >
> > Isn't that when some major scheduler changes went in? I'm not blaming
> > the scheduler, but rather I'm making the point that there are other
> > subsystems in the kernel that the networking interacts with that
> > influences performance at such a low level.
>
> ...IIRC, somebody in the past did even bisect his (probably netperf)
> 2.6.24-25 regression to some scheduler change (obviously it might or might
> not be related to this case of yours)...
I did find much regression with netperf TCP-RR-1/UDP-RR-1/UDP-RR-512. I start
1 serve and 1 client while binding them to a different logical processor in
different physical cpu.
Comparing with 2.6.22, the regression of TCP-RR-1 on 16-core tigerton is:
2.6.23 6%
2.6.24 6%
2.6.25 9.7%
2.6.26 14.5%
2.6.27-rc1 22%
Other regressions on other machines are similar.
yanmin
next prev parent reply other threads:[~2008-08-18 2:06 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-11 18:36 tbench regression on each kernel release from 2.6.22 -> 2.6.28 Christoph Lameter
2008-08-11 18:50 ` Kok, Auke
2008-08-11 18:56 ` Christoph Lameter
2008-08-11 21:15 ` David Miller
2008-08-11 21:33 ` Christoph Lameter
2008-08-11 21:50 ` David Miller
2008-08-11 21:56 ` Kok, Auke
2008-08-11 22:11 ` Rick Jones
2008-08-12 7:11 ` Andi Kleen
2008-08-12 18:57 ` Christoph Lameter
2008-08-12 8:13 ` Ilpo Järvinen
2008-08-18 2:05 ` Zhang, Yanmin [this message]
2008-08-18 7:53 ` Ilpo Järvinen
2008-08-19 0:56 ` Zhang, Yanmin
2008-08-18 14:07 ` Christoph Lameter
2008-08-18 14:31 ` Ray Lee
2008-08-18 14:34 ` Christoph Lameter
2008-08-19 1:01 ` Zhang, Yanmin
2008-08-18 1:48 ` Zhang, Yanmin
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