Re: [PATCH] sched/numa: recovered SD_PERFER_SIBLING on CPU domain

From: Peter Zijlstra
Date: Fri Jul 20 2012 - 08:58:46 EST


On Fri, 2012-07-20 at 14:19 +0800, Alex Shi wrote:
> commit 8e7fbcbc22c(sched: Remove stale power aware scheduling remnants
> and dysfunctional knobs) removed SD_PERFER_SIBLING on CPU domain
> On numa machine, that causes load_balance didn't perfer LCPU in same
> physical CPU package.
>
> It causes some regression on our numa machines from core2 to NHM and SNB.
> Recover this domain flag can recover the performance drop.
>
> This recovery doesn't has any bad impact on my all benchmarks specjbb,
> kbuild, fio, hackbench .. etc, on all my machines.
> Since it is a recovery, I assume it also has no bad impact for other
> platforms.
>
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>

Thanks!
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