Messages in this thread | | | Date | Tue, 29 Jul 2014 16:53:08 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/2] sched: fix and clean up calculate_imbalance |
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On Tue, Jul 29, 2014 at 04:49:52PM +0200, Peter Zijlstra wrote: > > @@ -6247,32 +6247,15 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s > > return fix_small_imbalance(env, sds); > > } > > > > - if (!busiest->group_imb) { > > - /* > > - * Don't want to pull so many tasks that a group would go idle. > > - * Except of course for the group_imb case, since then we might > > - * have to drop below capacity to reach cpu-load equilibrium. > > - */ > > - load_above_capacity = > > - (busiest->sum_nr_running - busiest->group_capacity_factor); > > - > > - load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_CAPACITY_SCALE); > > - load_above_capacity /= busiest->group_capacity; > > - } > > I think we want to retain that, esp. for the overloaded case. So that > wants to be: > > if (busiest->sum_nr_running > busiest->group_capacity_factor) > > Clearly it doesn't make sense for the !overload case, and we explicitly > want to avoid it in the imb case.
Ah, wait, I think I see why you want that gone. I was only expecting a correction fix wrt changing pick_busiest(), not also behaviour changes.
Lemme reconsider.
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