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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
