diff options
| author | Dietmar Eggemann <dietmar.eggemann@arm.com> | 2015-01-20 12:57:47 +0000 |
|---|---|---|
| committer | Robin Randhawa <robin.randhawa@arm.com> | 2015-04-09 12:26:15 +0100 |
| commit | 8cc211d406d7ce9acbbbe5a79552690d1d6dfded (patch) | |
| tree | dee628078780a1f79b6b612f3cdbd9f9bae60e77 | |
| parent | 3833bbffc228dee3a479c85c8153ddadaf4206a8 (diff) | |
sched: Introduce energy awareness into find_busiest_queue
In case that after the gathering of sched domain statistics the current
load balancing operation is still in energy-aware mode and a least
efficient sched group has been found, detect the least efficient cpu by
comparing the cpu efficiency (ratio between cpu usage and cpu energy
consumption) among all cpus of the least efficient sched group.
cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
| -rw-r--r-- | kernel/sched/fair.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 01d8f52ccad4..748ad1532538 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6723,6 +6723,37 @@ static struct rq *find_busiest_queue(struct lb_env *env, unsigned long busiest_load = 0, busiest_capacity = 1; int i; + if (env->use_ea) { + struct rq *costliest = NULL; + unsigned long costliest_usage = 1024, costliest_energy = 1; + + for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { + unsigned long usage = get_cpu_usage(i); + struct rq *rq = cpu_rq(i); + struct sched_domain *sd = rcu_dereference(rq->sd); + struct energy_env eenv = { + .sg_top = sd->groups, + .usage_delta = 0, + .src_cpu = -1, + .dst_cpu = -1, + }; + unsigned long energy = sched_group_energy(&eenv); + + /* + * We're looking for the minimal cpu efficiency + * min(u_i / e_i), crosswise multiplication leads to + * u_i * e_j < u_j * e_i with j as previous minimum. + */ + if (usage * costliest_energy < costliest_usage * energy) { + costliest_usage = usage; + costliest_energy = energy; + costliest = rq; + } + } + + return costliest; + } + for_each_cpu_and(i, sched_group_cpus(group), env->cpus) { unsigned long capacity, wl; |