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

Mel Gorman
2009-02-26T11:03:52Z

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?

> 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