Messages in this thread | | | From | Vincent Guittot <> | Date | Tue, 18 Feb 2020 15:15:22 +0100 | Subject | Re: [PATCH v2 1/5] sched/fair: Reorder enqueue/dequeue_task_fair path |
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On Tue, 18 Feb 2020 at 14:22, Peter Zijlstra <peterz@infradead.org> wrote: > > On Tue, Feb 18, 2020 at 01:37:37PM +0100, Dietmar Eggemann wrote: > > On 14/02/2020 16:27, Vincent Guittot wrote: > > > The walk through the cgroup hierarchy during the enqueue/dequeue of a task > > > is split in 2 distinct parts for throttled cfs_rq without any added value > > > but making code less readable. > > > > > > Change the code ordering such that everything related to a cfs_rq > > > (throttled or not) will be done in the same loop. > > > > > > In addition, the same steps ordering is used when updating a cfs_rq: > > > - update_load_avg > > > - update_cfs_group > > > - update *h_nr_running > > > > Is this code change really necessary? You pay with two extra goto's. We > > still have the two for_each_sched_entity(se)'s because of 'if > > (se->on_rq); break;'. > > IIRC he relies on the presented ordering in patch #5 -- adding the > running_avg metric.
Yes, that's the main reason, updating load_avg before h_nr_running
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