Re: Scheduler behaviour

[Arjan van de Ven]

On Wed, 05 Dec 2007 21:15:30 +0100
Holger Wolf <wolf@xxxxxxxxxxxxxxxxxx> 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 ;)


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