From: Mel Gorman <mgorman@suse.de>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/numa: use runnable_avg to classify node
Date: Thu, 27 Aug 2020 16:35:34 +0100 [thread overview]
Message-ID: <20200827153534.GF3033@suse.de> (raw)
In-Reply-To: <20200825121818.30260-1-vincent.guittot@linaro.org>
On Tue, Aug 25, 2020 at 02:18:18PM +0200, Vincent Guittot wrote:
> Use runnable_avg to classify numa node state similarly to what is done for
> normal load balancer. This helps to ensure that numa and normal balancers
> use the same view of the state of the system.
>
> - large arm64system: 2 nodes / 224 CPUs
> hackbench -l (256000/#grp) -g #grp
>
> grp tip/sched/core +patchset improvement
> 1 14,008(+/- 4,99 %) 13,800(+/- 3.88 %) 1,48 %
> 4 4,340(+/- 5.35 %) 4.283(+/- 4.85 %) 1,33 %
> 16 3,357(+/- 0.55 %) 3.359(+/- 0.54 %) -0,06 %
> 32 3,050(+/- 0.94 %) 3.039(+/- 1,06 %) 0,38 %
> 64 2.968(+/- 1,85 %) 3.006(+/- 2.92 %) -1.27 %
> 128 3,290(+/-12.61 %) 3,108(+/- 5.97 %) 5.51 %
> 256 3.235(+/- 3.95 %) 3,188(+/- 2.83 %) 1.45 %
>
> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
The testing was a mixed bag of wins and losses but wins more than it
loses. Biggest loss was a 9.04% regression on nas-SP using openmp for
parallelisation on Zen1. Biggest win was around 8% gain running
specjbb2005 on Zen2 (with some major gains of up to 55% for some thread
counts). Most workloads were stable across multiple Intel and AMD
machines.
There were some oddities in changes in NUMA scanning rate but that is
likely a side-effect because the locality over time for the same loads
did not look obviously worse. There was no negative result I could point
at that was not offset by a positive result elsewhere. Given it's not
a univeral win or loss, matching numa and lb balancing as closely as
possible is best so
Reviewed-by: Mel Gorman <mgorman@suse.de>
Thanks.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2020-08-27 15:35 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-25 12:18 [PATCH] sched/numa: use runnable_avg to classify node Vincent Guittot
2020-08-25 13:58 ` Mel Gorman
2020-08-25 15:52 ` Vincent Guittot
2020-08-27 15:35 ` Mel Gorman [this message]
2020-08-27 15:43 ` Vincent Guittot
2020-08-27 18:22 ` Mel Gorman
2020-08-28 6:47 ` Vincent Guittot
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