Messages in this thread | | | Date | Mon, 22 Jun 2015 06:26:01 +0800 | From | Yuyang Du <> | Subject | Re: [PATCH v8 1/4] sched: Remove rq's runnable avg |
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Hi Dietmar,
On Fri, Jun 19, 2015 at 07:27:24PM +0100, Dietmar Eggemann wrote: > Hi Yuyang, > > On 15/06/15 20:26, Yuyang Du wrote: > > The current rq->avg is not used at all since its merge into kernel, > > and the code is in the scheduler's hot path, so remove it. > > are you sure that this is the case? I was always under the impression > that w/ CONFIG_FAIR_GROUP_SCHED=y rq->avg (runnable_avg_sum, avg_period) > is used to calculate contrib in __update_tg_runnable_avg() for the root > group (cfs_rq->tg->css.id = 1). > > On tg's w/ cfs_rq->tg->css.id > 1, se->avg (runnable_avg_sum, > avg_period) is used instead but we simply don't have a tg related se for > the root group. IMHO, that's why we have this rq::avg.
Yes, I agree. But the root group's avg is not useful anyway. If it is, we sure should keep it.
> I understand that w/ the second patch in your series you don't need > rq::avg any more.
And the rq->avg can be replaced by the root cfs_rq's util_avg, too.
Thanks, Yuyang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in Please read the FAQ at http://www.tux.org/lkml/
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