Messages in this thread | | | Date | Wed, 8 Jan 2014 13:33:29 +0000 | From | Morten Rasmussen <> | Subject | Re: [RFC] sched: CPU topology try |
| |
On Wed, Jan 08, 2014 at 01:04:07PM +0000, Peter Zijlstra wrote: > On Wed, Jan 08, 2014 at 12:52:28PM +0000, Morten Rasmussen wrote: > > > If I remember correctly, Alex used the rq runnable_avg_sum (in rq->avg) > > for this. It is the most obvious choice, but it takes ages to reach > > 100%. > > > > #define LOAD_AVG_MAX_N 345 > > > > Worst case it takes 345 ms from the system is becomes fully utilized > > after a long period of idle until the rq runnable_avg_sum reaches 100%. > > > > An unweigthed version of cfs_rq->runnable_load_avg and blocked_load_avg > > wouldn't have that delay. > > Right.. not sure we want to involve blocked load on the utilization > metric, but who knows maybe that does make sense. > > But yes, we need unweighted runnable_avg.
I'm not sure about the blocked load either.
> > > Also, if we are changing the load balance behavior when all cpus are > > fully utilized > > We already have this tipping point. See all the has_capacity bits. But > yes, it'd get more involved I suppose.
I'll have a look.
| |