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From: "Ilpo Järvinen" <ilpo.jarvinen@helsinki.fi>
To: David Miller <davem@davemloft.net>
Cc: 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: Tue, 12 Aug 2008 11:13:15 +0300 (EEST)	[thread overview]
Message-ID: <Pine.LNX.4.64.0808121058550.4551@wrl-59.cs.helsinki.fi> (raw)
In-Reply-To: <20080811.141501.01468546.davem@davemloft.net>

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.

  parent reply	other threads:[~2008-08-12  8:13 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 [this message]
2008-08-18  2:05     ` Zhang, Yanmin
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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