Re: [RFC PATCH 00/19] Cleanup and optimise the page allocator V2

Mel Gorman
2009-02-26T11:22:49Z

On Thu, Feb 26, 2009 at 01:18:59PM +0200, Pekka Enberg wrote:
> On Thu, 2009-02-26 at 11:03 +0000, Mel Gorman wrote:
> > On Thu, Feb 26, 2009 at 05:10:27PM +0800, Lin Ming wrote:
> > > We tested this v2 patch series with 2.6.29-rc6 on different machines.
> > >
> >
> > Wonderful, thanks.
> >
> > > 4P qual-core 2P qual-core 2P qual-core HT
> > > tigerton stockley Nehalem
> > > ------------------------------------------------
> > > tbench +3% +2% 0%
> >
> > Nice.
> >
> > > oltp -2% 0% 0%
> >
> > This is a big disappointment and somewhat confusing that it is so
> > severe. For sysbench I was seeing on six different machines;
> >
> > 50834.14 51763.08 1.79%
> > 61852.08 61966.58 0.18%
> > 5935.98 5980.06 0.74%
> > 29227.78 30167.72 3.12%
> > 66702.67 66534.76 -0.25%
> > 26643.18 26542.59 -0.38%
> >
> > So, two smallish regressions but mainly gains. Then again, I'm becoming
> > more and more convinced that sysbench doesn't really represent a proper
> > OLTP workload.
> >
> > I'd like to understand more how the page allocator at least was being used
> > during your tests. Would it be possible to get a full profile (including
> > instruction if possible and the vmlinux file) for both kernels please?
> >
> > If you can get the profiles, confirm the regression is still there as
> > sometimes profiling can alter the outcome. Even if this happens, the
> > profile will tell me where time is being spent.
> >
> > > aim7 0% 0% 0%
> > > specjbb2005 +3% 0% 0%
> > > hackbench 0% 0% 0%
> > >
> > > netperf:
> > > TCP-S-112k 0% -1% 0%
> > > TCP-S-64k 0% -1% +1%
> > > TCP-RR-1 0% 0% +1%
> > > UDP-U-4k -2% 0% -2%
> >
> > Pekka, for this test was SLUB or the page allocator handling the 4K
> > allocations?
>
> The page allocator. The pass-through revert is not in 2.6.29-rc6 and I
> won't be sending it until 2.6.30 opens up.
>

In that case, Lin, could I also get the profiles for UDP-U-4K please so I
can see how time is being spent and why it might have gotten worse?

Thanks

> >
> > > UDP-U-1k +3% 0% 0%
> > > UDP-RR-1 0% 0% 0%
> > > UDP-RR-512 -1% 0% +1%
> > >
> > > Lin Ming
> > >
> >
> > Thanks a million for testing.
> >
>

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab