[sles-beta] intel_idle

[Scott Bahling]

On Wed, 2014-07-23 at 06:55 +0000, Waite, Dick wrote:
> Grand Day,
> 
>     When running some SLES11 on X86_64 sites some time ago the "batch"
> jobs were taking 30-50% more wall clock time. After some time a
> work-a-round was found to amend the "Intel_Idle" parm. There was some
> chatter at the time that a "better" fix would be available with a
> later Linux release. I'm going to visit one of our customers who had
> this issue in a few weeks time, what news do I have for them?

It depends on the exact tuning ("work-a-round") used.

There has been an optimization related to disabling promotion to C1E
state so using intel_idle.max_cstate=1 might give better results with
SUSE Linux Enterprise Server 12 and remove the need to disable the
intel_idle driver completely. It depends on the workload and CPU model
in use.

Other than that, the intel_idle driver and it's parameters should work
the same in 12 as in 11 - meaning if c-states affect your workload,
tuning of the intel_idle driver might be necessary. 

Best Regards,

Scott

-- 
Scott Bahling     | Technical Account Manager - Team Lead
+49 911-74053-121 | Mobile: +49 173-587-6977 | sbahling at suse.com
SUSE Linux Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 16746 (AG Nuremberg)