Re: [Xen-devel] [PATCH] credit: Change default timeslice to 5ms

[Dario Faggioli <dario.faggioli@xxxxxxxxxx>]

On mer, 2014-03-05 at 16:29 +0000, George Dunlap wrote:
> The 30ms timeslice was chosen nearly a decade ago now, with cpu
> "burning" workloads in mind.  In the mean time, processors have gotten
> faster and VMEXITs have gotten faster.  A timeslice of 30ms has a
> major cost when running latency-sensitive workloads like network or
> audio streaming: getting caught behind just one or two other VMs can
> introduce a processing delay of up to 60ms, and the "round-robin"
> nature of the credit scheduler means this delay may be introduced
> every time the VM yields for periods of time.
> 
> The XenServer performance team at Citrix have done extensive testing
> with various timeslices, including 30ms, 10ms, 5ms, and 2ms.  None of
> the workloads exhibited any performance degradation with a 5ms
> timeslice.
> 
> Signed-off-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
> ---
> CC: Jan Beulich <jbeulich@xxxxxxxx>
> CC: Tim Deegan <tim@xxxxxxx>
> CC: Keir Fraser <keir@xxxxxxx>
> CC: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
> CC: Marcus Granado <Marcus.Granado@xxxxxxxxxxxxx>
> ---
>
Reviewed-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>

Regards,
Dario

-- 
<<This happens because I choose it to happen!>> (Raistlin Majere)
-----------------------------------------------------------------
Dario Faggioli, Ph.D, http://about.me/dario.faggioli
Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK)

Attachment: signature.asc
Description: This is a digitally signed message part

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel