Re: [PATCH 2/2] sched: Rewrite per entity runnable load average tracking

From: Yuyang Du
Date: Wed Jul 09 2014 - 22:42:27 EST


On Wed, Jul 09, 2014 at 10:08:42AM -0700, bsegall@xxxxxxxxxx wrote:

> > That I believe is not a problem. It is a matter of when cfs_rq->load.weight
> > changes and when we look at it to contribute to the cfs_rq's load_avg.
> > Fortunately, we will not miss any change of cfs_rq->load.weight, always
> > contributing to the load_avg the right amount. Put another way, we always
> > use the right cfs_rq->load.weight.
>
> You always call __update_load_avg with every needed load.weight, but if
> now - sa->last_update_time < 1024, then it will not do anything with
> that weight, and the next actual update may be with a different weight.

Oh, yes, I finally understand, :) You are right. That is the matter of 1ms period.
Within period boundary, everything will be lost.

Thanks,
Yuyang
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