Re: sysbench+mysql(oltp, readonly) 30% regression with 2.6.26-rc1

From: Mike Galbraith
Date: Fri May 09 2008 - 03:33:35 EST



On Fri, 2008-05-09 at 08:51 +0200, Peter Zijlstra wrote:
> > > > -rc1. Do you have the fix below applied?
> > >
> > > Oooh - good catch, that seems to be a post -rc1 merge.
> > >
> > > Yes this is required.
>
> > With below patch+previous_fix_weight_calc, the result is improved, but is still
> > about 10% worse than the one of pure 2.6.26-rc1.
> > Number of threads: 16
> > read/write requests: 6104336 (50867.11 per sec.)
> >
>
> So puzzling - could you try -git + fix_weight_calc, as I think that is
> what Mike tested and proved good on his Quad.

If he still has group scheduling enabled, my box agrees that there's a
regression. I got mysql running, and tested with group scheduling both
enabled and disabled, results attached. (for some reason, I can only
test up to 64 threads with mysql though)

-Mike

Attachment: yy.pdf
Description: Adobe PDF document