| Date | Wed, 25 Mar 2015 16:50:40 -0700 | From | Sai Gurrappadi <> | Subject | Re: [RFCv3 PATCH 43/48] sched: Introduce energy awareness into detach_tasks |
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On 02/04/2015 10:31 AM, Morten Rasmussen wrote: > From: Dietmar Eggemann <dietmar.eggemann@arm.com> > while (!list_empty(tasks)) { > @@ -6121,6 +6121,20 @@ static int detach_tasks(struct lb_env *env) > if (!can_migrate_task(p, env)) > goto next; > > + if (env->use_ea) { > + struct energy_env eenv = { > + .src_cpu = env->src_cpu, > + .dst_cpu = env->dst_cpu, > + .usage_delta = task_utilization(p), > + }; > + int e_diff = energy_diff(&eenv); > + > + if (e_diff >= 0) > + goto next; > + > + goto detach; > + } > + > load = task_h_load(p); > > if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed) > @@ -6129,6 +6143,7 @@ static int detach_tasks(struct lb_env *env) > if ((load / 2) > env->imbalance) > goto next; > > +detach: > detach_task(p, env); > list_add(&p->se.group_node, &env->tasks);
Hi Morten, Dietmar,
Wouldn't the above energy_diff() use the 'old' value of dst_cpu's util? Tasks are detached/dequeued in this loop so they have their util contrib. removed from src_cpu but their contrib. hasn't been added to dst_cpu yet (happens in attach_tasks).
Thanks, -Sai
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