Messages in this thread | | | Date | Tue, 23 Jun 2015 17:49:44 +0100 | From | Dietmar Eggemann <> | Subject | Re: [PATCH v9 1/4] sched: Remove rq's runnable avg |
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On 23/06/15 01:08, Yuyang Du wrote: > The per-rq runnable averages (rq->avg) was introduced by Ben with this commit: > > commit 18bf2805d9b30cb823d4919b42cd230f59c7ce1f > Author: Ben Segall <bsegall@google.com> > Date: Thu Oct 4 12:51:20 2012 +0200 > > sched: Maintain per-rq runnable averages > > Since runqueues do not have a corresponding sched_entity we instead embed a > sched_avg structure directly. > > Signed-off-by: Ben Segall <bsegall@google.com> > Reviewed-by: Paul Turner <pjt@google.com> > Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> > Link: http://lkml.kernel.org/r/20120823141506.442637130@google.com > Signed-off-by: Ingo Molnar <mingo@kernel.org> > > With CONFIG_FAIR_GROUP_SCHED=y, the rq->avg (runnable_avg_sum, avg_period) is > used to calc the contrib in __update_tg_runnable_avg() for the root group. > > But the root group's load data is never consumed since its merge into kernel > in 2012. The basic reason is we have just one root group, and it is > meaningless to give it weight. As the extra code is in the scheduler's > hot path, so it is better to remove it. > > Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
There is an additional clean-up possible since idle_[enter|exit]_fair() are empty now.
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