Re: [PATCH 0/2] fix the itimer regression (BZ 12618)

[Ingo Molnar <mingo@elte.hu>]

* Lin Ming <ming.m.lin@intel.com> wrote:

> On Fri, 2009-02-06 at 23:18 +0800, Ingo Molnar wrote:
> > * Zhang, Yanmin <yanmin_zhang@linux.intel.com> wrote:
> > 
> > > On Thu, 2009-02-05 at 13:06 +0100, Ingo Molnar wrote:
> > > > * Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> > > > 
> > > > > This should hopefully address all the itimer borkage.
> > > > 
> > > > Applied to tip:timers/urgent, thanks Peter!
> > > > 
> > > > Yanmin: could you check hacbench_pth with latest tip/master, do
> > > > these fixes resolve that 3% regression you reported?
> > >
> > > Lin Ming tested it and hackbench_pth/volanoMark regression all disappear. 
> > > But oltp has a regression. We think oltp new regression isn't related to 
> > > the patch. Ming is investigating it.
> > 
> > Potential suspects for oltp regression would be:
> > 
> >  3d39870: sched_rt: don't use first_cpu on cpumask created with cpumask_and
> >  a571bbe: sched: fix buddie group latency
> >  a9f3e2b: sched: clear buddies more aggressively
> >  1596e29: sched: symmetric sync vs avg_overlap
> >  d942fb6: sched: fix sync wakeups
> 
> I tested the latest tip-master branch.
> After reverting "d942fb6: sched: fix sync wakeups", the oltp regression
> on the 8cores Stockley machine is mostly fixed.
> 
> On another 4*4 cores Tigerton machine, oltp has more than 10% regression
> with 2.6.29-rc4 compared with 2.6.29-rc3.

ok, that commit needs fixed or reverted. Peter, Mike?

	Ingo