Messages in this thread | | | Subject | Re: [PATCH v2] sched: Fast idling of CPU when system is partially loaded | From | Tim Chen <> | Date | Mon, 23 Jun 2014 11:59:40 -0700 |
| |
On Mon, 2014-06-23 at 20:50 +0200, Peter Zijlstra wrote: > On Mon, Jun 23, 2014 at 09:40:45AM -0700, Tim Chen wrote: > > > > @@ -5886,7 +5886,7 @@ static inline void update_sg_lb_stats(st > > > > > > sgs->group_load += load; > > > sgs->sum_nr_running += rq->nr_running; > > > - if (overload && rq->nr_running > 1) > > > + if (rq->nr_running > 1) > > > *overload = true; > > > #ifdef CONFIG_NUMA_BALANCING > > > sgs->nr_numa_running += rq->nr_numa_running; > > > With this change, we'll be returning the overload indicator > > that we don't use for non-root domains, which will be > > extra work in sg_lb_stats as it loops through each rq checking > > the nr_running to update the indicator. I was hoping to avoid > > that if possible. > > What extra work? We already load nr_running and overloaded is on-stack > and should be quite dirty already due to that.
Okay then. I'll need to modify the v3 patch with the following bits:
- /* only need to update overload indicator for root domain */ - if (!env->sd->parent && rq->nr_running > 1) + if (rq->nr_running > 1) *overload = true;
Just sent v3 patch out before your email reached me.
Tim
| |