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

[Mike Galbraith]

On Fri, 2008-05-09 at 10:02 +0200, Peter Zijlstra wrote:
> On Fri, 2008-05-09 at 09:58 +0200, Mike Galbraith wrote:
> > On Fri, 2008-05-09 at 09:50 +0200, Peter Zijlstra wrote:
> > > On Fri, 2008-05-09 at 09:32 +0200, Mike Galbraith wrote:
> > > > 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)
> > > 
> > > Hm, ok. Does the patch at hand improve or regress the group config for
> > > you?
> > 
> > I'm testing got.today.
> > 
> > You mean 46151122e0a2e80e5a6b2889f595e371fe2b600d?
> 
> Exactly - Yanmin says it makes it worse for him, I'm wondering if you
> can see a similar problem with group scheduling enabled.

Nope, same fugly curve +-jitter.

	-Mike

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