Re: [tbench regression fixes]: digging out smelly deadmen.

From: Mike Galbraith
Date: Sat Oct 25 2008 - 01:53:24 EST


On Fri, 2008-10-24 at 22:15 -0700, David Miller wrote:
> From: Mike Galbraith <efault@xxxxxx>
> Date: Sat, 25 Oct 2008 06:05:01 +0200
>
> > My test data indicates (to me anyway) that there is another source of
> > localhost throughput loss in .27. In that data, there is no hrtick
> > overhead since I didn't have highres timers enabled, and computational
> > costs added in .27 were removed. Dunno where it lives, but it does
> > appear to exist.
>
> Disabling TSO on loopback doesn't fix that bit for you?

No. Those numbers are with TSO/GSO disabled.

I did a manual 100% sched and everything related revert to 26 scheduler,
and had ~the same result as these numbers. 27 with 100% revert actually
performed a bit _worse_ for me than 27 with it's overhead.. which
puzzles me greatly.

-Mike

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