Re: [PATCH v2 10/12] Maintain preemptability count even for !CONFIG_PREEMPT kernels

Peter Zijlstra
2009-11-30T11:05:14Z

On Mon, 2009-11-30 at 11:59 +0100, Peter Zijlstra wrote:
> On Mon, 2009-11-30 at 12:58 +0200, Gleb Natapov wrote:
> > On Mon, Nov 30, 2009 at 12:56:12PM +0200, Gleb Natapov wrote:
> > > On Tue, Nov 24, 2009 at 09:14:03AM -0600, Christoph Lameter wrote:
> > > > On Tue, 24 Nov 2009, Gleb Natapov wrote:
> > > >
> > > > > On Mon, Nov 23, 2009 at 11:30:02AM -0600, Christoph Lameter wrote:
> > > > > > This adds significant overhead for the !PREEMPT case adding lots of code
> > > > > > in critical paths all over the place.
> > > > > I want to measure it. Can you suggest benchmarks to try?
> > > >
> > > > AIM9 (reaim9)?
> > > Below are results for kernel 2.6.32-rc8 with and without the patch (only
> > > this single patch is applied).
> > >
> > Forgot to tell. The results are average between 5 different runs.
>
> Would be good to also report the variance over those 5 runs, allows us
> to see if the difference is within the noise.

Got pointed to the fact that there is a stddev column right there.

Must be Monday or something ;-)