From: Arjan van de Ven <arjan@infradead.org>
To: Holger.Wolf@de.ibm.com
Cc: wolf@linux.vnet.ibm.com, mingo@elte.hu, schwidefsky@de.ibm.com,
linux-kernel@vger.kernel.org
Subject: Re: Scheduler behaviour
Date: Wed, 5 Dec 2007 13:26:31 -0800 [thread overview]
Message-ID: <20071205132631.79940bd5@laptopd505.fenrus.org> (raw)
In-Reply-To: <475706E2.50805@linux.vnet.ibm.com>
On Wed, 05 Dec 2007 21:15:30 +0100
Holger Wolf <wolf@linux.vnet.ibm.com> wrote:
> We discovered performance degradation with dbench when using kernel
> 2.6.23 compared to kernel 2.6.22.
>
> In our case we booted a Linux in a IBM System z9 LPAR with 256MB of
> ram with 4 CPU's. This system uses a striped LV with 16 disks on a
> Storage Server connected via 8 4GBit links.
> A dbench was started on that system performing I/O operations on the
> striped LV. dbench runs were performed with 1 to 62 processes.
> Measurements with a 2.6.22 kernel were compared to measurements with
> a 2.6.23 kernel. We saw a throughput degradation from 7.2 to 23.4
this is good news!
dbench rewards unfair behavior... so higher dbench usually means a
worse kernel ;)
--
If you want to reach me at my work email, use arjan@linux.intel.com
For development, discussion and tips for power savings,
visit http://www.lesswatts.org
next prev parent reply other threads:[~2007-12-05 21:28 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-05 20:15 Scheduler behaviour Holger Wolf
2007-12-05 21:15 ` Peter Zijlstra
2007-12-05 21:21 ` Ingo Molnar
2007-12-05 21:26 ` Arjan van de Ven [this message]
2007-12-06 21:53 ` Jarek Poplawski
2007-12-07 16:29 ` Holger Wolf
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