Messages in this thread | | | Date | Thu, 8 May 2008 11:10:47 +0530 | From | Dhaval Giani <> | Subject | Re: volanoMark regression with kernel 2.6.26-rc1 |
| |
On Thu, May 08, 2008 at 01:18:34PM +0800, Zhang, Yanmin wrote: > > On Wed, 2008-05-07 at 23:03 +0530, Dhaval Giani wrote: > > On Tue, May 06, 2008 at 05:22:07PM +0530, Dhaval Giani wrote: > > > On Tue, May 06, 2008 at 10:06:30AM +0800, Zhang, Yanmin wrote: > > > > Comparing with 2.6.25, volanoMark has big regression with kernel 2.6.26-rc1. > > > > It's about 50% on my 8-core stoakley, 16-core tigerton, and Itanium Montecito. > > > > > > > > With bisect, I located below patch. > > > > > > > > 18d95a2832c1392a2d63227a7a6d433cb9f2037e is first bad commit > > > > commit 18d95a2832c1392a2d63227a7a6d433cb9f2037e > > > > Author: Peter Zijlstra <a.p.zijlstra@chello.nl> > > > > Date: Sat Apr 19 19:45:00 2008 +0200 > > > > > > > > sched: fair-group: SMP-nice for group scheduling > > > > > > > > Implement SMP nice support for the full group hierarchy. > > > > > > > > If I reverse the patch with resolving some conflictions, volanoMark result could > > > > be restored completely. > > > > > > > > > > ok, that's bad. Let's get vatsa and Ingo also involved. > > > > > > > Just to confirm, do you still have a performance regression with > > !group_sched? > I just tried it with CONFIG_GROUP_SCHED=n a moment ago. The regression becomes less than 3%. >
One more thing if you can try out, please set the shares for other users to 2 except for the one which is running the benchmark. You can set it at /sys/kernel/uids/<uid>/cpu_share
-- regards, Dhaval
| |