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From: Valentin Schneider <vschneid@redhat.com>
To: Kyle Meyer <kyle.meyer@hpe.com>, linux-kernel@vger.kernel.org,
 yury.norov@gmail.com, andriy.shevchenko@linux.intel.com,
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Cc: russ.anderson@hpe.com, dimitri.sivanich@hpe.com, steve.wahl@hpe.com,
 Kyle Meyer <kyle.meyer@hpe.com>
Subject: Re: [PATCH v2 2/2] sched/topology: Optimize topology_span_sane()
In-Reply-To: <20240410213311.511470-3-kyle.meyer@hpe.com>
References: <20240410213311.511470-1-kyle.meyer@hpe.com>
 <20240410213311.511470-3-kyle.meyer@hpe.com>
Date: Mon, 15 Apr 2024 13:50:08 +0200
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On 10/04/24 16:33, Kyle Meyer wrote:
> Optimize topology_span_sane() by removing duplicate comparisons.
>
> Since topology_span_sane() is called inside of for_each_cpu(), each
> pervious CPU has already been compared against every other CPU. The
> current CPU only needs to be compared against higher-numbered CPUs.
>
> The total number of comparisons is reduced from N * (N - 1) to
> N * (N - 1) / 2 on each non-NUMA scheduling domain level.
>
> Signed-off-by: Kyle Meyer <kyle.meyer@hpe.com>
> Reviewed-by: Yury Norov <yury.norov@gmail.com>
> Acked-by: Vincent Guittot <vincent.guittot@linaro.org>

Reviewed-by: Valentin Schneider <vschneid@redhat.com>