Re: [mm] f7b5d647946: -3.0% dbench.throughput-MB/sec

From: Mel Gorman
Date: Tue Aug 19 2014 - 10:36:46 EST


On Tue, Aug 19, 2014 at 12:41:34PM +0800, Fengguang Wu wrote:
> Hi Mel,
>
> We noticed a minor dbench throughput regression on commit
> f7b5d647946aae1647bf5cd26c16b3a793c1ac49 ("mm: page_alloc: abort fair
> zone allocation policy when remotes nodes are encountered").
>
> testcase: ivb44/dbench/100%
>
> bb0b6dffa2ccfbd f7b5d647946aae1647bf5cd26
> --------------- -------------------------
> 25692 ± 0% -3.0% 24913 ± 0% dbench.throughput-MB/sec
> 6974259 ± 6% -12.1% 6127616 ± 0% meminfo.DirectMap2M
> 18.43 ± 0% -4.6% 17.59 ± 0% turbostat.RAM_W
> 9302 ± 0% -3.6% 8965 ± 1% time.user_time
> 1425791 ± 1% -2.0% 1396598 ± 0% time.involuntary_context_switches
>
> Disclaimer:
> Results have been estimated based on internal Intel analysis and are provided
> for informational purposes only. Any difference in system hardware or software
> design or configuration may affect actual performance.
>

DirectMap2M changing is a major surprise and doesn't make sense for this
machine. Did the amount of memory in the machine change between two
tests?

--
Mel Gorman
SUSE Labs
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