Re: [performance bug] kernel building regression on 64 LCPUs machine

From: Corrado Zoccolo
Date: Sat Feb 26 2011 - 09:45:27 EST

On Thu, Feb 24, 2011 at 1:13 PM, Jan Kara <jack@xxxxxxx> wrote:
> On Wed 23-02-11 16:24:47, Alex,Shi wrote:
>> Though these patches can not totally recovered the problem, but they are
>> quite helpful with ccache enabled situation. It increase 10% performance
>> on 38-rc1 kernel.
> ÂOK and what was the original performance drop with WRITE_SYNC change?
>> I have tried to enabled they to latest rc6 kernel but failed. the vmstat output is here:
>> with patches:
> ÂI'm attaching patches rebased on top of latest Linus's tree.
> Corrado, could you possibly run your fsync-heavy tests so that we see
> whether there isn't negative impact of my patches on your fsync-heavy
> workload? Thanks.
The workload was actually Jeff's, and the stalls that my change tried
to mitigate showed up on his enterprise class storage. Adding him so
he can test it.

> Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ÂHonza
> --
> Jan Kara <jack@xxxxxxx>
> SUSE Labs, CR


dott. Corrado Zoccolo             mailto:czoccolo@xxxxxxxxx
PhD - Department of Computer Science - University of Pisa, Italy
The self-confidence of a warrior is not the self-confidence of the average
man. The average man seeks certainty in the eyes of the onlooker and calls
that self-confidence. The warrior seeks impeccability in his own eyes and
calls that humbleness.
              Â Tales of Power - C. Castaneda
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