On Tue, Jul 21, 2015 at 06:18:46PM +0800, Boqun Feng wrote: > On Tue, Jul 21, 2015 at 08:44:01AM +0800, Yuyang Du wrote: > > On Tue, Jul 21, 2015 at 09:08:07AM +0800, Boqun Feng wrote: > > > Hi Yuyang, > > > > > > On Wed, Jul 15, 2015 at 08:04:41AM +0800, Yuyang Du wrote: > > > > The cfs_rq's load_avg is composed of runnable_load_avg and > > > > blocked_load_avg. > > > > Before this series, sometimes the runnable_load_avg is used, and > > > > sometimes > > > > the load_avg is used. Completely replacing all uses of runnable_load_avg > > > > with load_avg may be too big a leap, i.e., the blocked_load_avg is > > > > concerned > > > > to result in overrated load. Therefore, we get runnable_load_avg back. > > > > > > > > The new cfs_rq's runnable_load_avg is improved to be updated with all > > > > of the > > > > runnable sched_eneities at the same time, so the one sched_entity > > > > updated and > > > > the others stale problem is solved. > > > > > > > > > > How about tracking cfs_rq's blocked_load_avg instead of > > > runnable_load_avg, because, AFAICS: > > > > > > cfs_rq->runnable_load_avg = se->avg.load_avg - cfs_rq->blocked_load_avg. > > > > No, cfs_rq->runnable_load_avg = cfs_rq->avg.load_avg - > > cfs_rq->blocked_load_avg, > > without rounding errors and the like. > > > > Oh, sorry.. yeah, you're right here. >
The point is that you have already tracked the sum of runnable_load_avg and blocked_load_avg in cfs_rq->avg.load_avg. If you're going to track part of the sum, you'd better track the one that's updated less frequently, right? Anyway, this idea just comes into my mind. I wonder which is udpated less frequently myself too. ;-) So I ask to see whether there is something we can improve. Regards, Boqun
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