Messages in this thread | | | Date | Wed, 3 Feb 2016 17:21:21 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH 1/1] sched: Make schedstats a runtime tunable that is disabled by default v4 |
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> 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
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