From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
Mike Galbraith <mgalbraith@suse.de>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] sched: Make schedstats a runtime tunable that is disabled by default v4
Date: Wed, 3 Feb 2016 17:21:21 +0530 [thread overview]
Message-ID: <20160203115121.GB28611@linux.vnet.ibm.com> (raw)
In-Reply-To: <1454497668-22297-1-git-send-email-mgorman@techsingularity.net>
> Changelog since v3
> o Force enable stats during profiling and latencytop
>
> Changelog since V2
> o Print stats that are not related to schedstat
> o Reintroduce a static inline for update_stats_dequeue
>
> Changelog since V1
> o Introduce schedstat_enabled and address Ingo's feedback
> o More schedstat-only paths eliminated, particularly ttwu_stat
>
> schedstats is very useful during debugging and performance tuning but it
> incurs overhead. As such, even though it can be disabled at build time,
> it is often enabled as the information is useful. This patch adds a
> kernel command-line and sysctl tunable to enable or disable schedstats on
> demand. It is disabled by default as someone who knows they need it can
> also learn to enable it when necessary.
>
> The benefits are workload-dependent but when it gets down to it, the
> difference will be whether cache misses are incurred updating the shared
> stats or not. These measurements were taken from a 48-core 2-socket machine
> with Xeon(R) E5-2670 v3 cpus although they were also tested on a single
> socket machine 8-core machine with Intel i7-3770 processors.
>
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
--
Thanks and Regards
Srikar Dronamraju
prev parent reply other threads:[~2016-02-03 11:52 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 11:07 [PATCH 1/1] sched: Make schedstats a runtime tunable that is disabled by default v4 Mel Gorman
2016-02-03 11:28 ` Ingo Molnar
2016-02-03 11:39 ` Mel Gorman
2016-02-03 12:49 ` Ingo Molnar
2016-02-03 13:32 ` Mel Gorman
2016-02-03 14:56 ` Mel Gorman
2016-02-03 11:51 ` Srikar Dronamraju [this message]
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