diff options
| author | Morten Rasmussen <morten.rasmussen@arm.com> | 2015-01-23 14:20:38 +0000 |
|---|---|---|
| committer | Robin Randhawa <robin.randhawa@arm.com> | 2015-04-09 12:26:14 +0100 |
| commit | 2359e465f1f15ff9e3f7c59ea70442f6ae54e4a5 (patch) | |
| tree | 3315fea131a4c10f6e476fb8b70c4e0135dcdcf6 | |
| parent | 10b7c4b6b249816aea7275ba0a3d0d551ce76961 (diff) | |
sched: Bias new task wakeups towards higher capacity cpus
Make wake-ups of new tasks (find_idlest_group) aware of any differences
in cpu compute capacity so new tasks don't get handed off to a cpus with
lower capacity.
cc: Ingo Molnar <mingo@redhat.com>
cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
| -rw-r--r-- | kernel/sched/fair.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 646744664884..a76777fa6079 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4659,6 +4659,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, { struct sched_group *idlest = NULL, *group = sd->groups; unsigned long min_load = ULONG_MAX, this_load = 0; + unsigned long this_cpu_cap = 0, idlest_cpu_cap = 0; int load_idx = sd->forkexec_idx; int imbalance = 100 + (sd->imbalance_pct-100)/2; @@ -4666,7 +4667,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, load_idx = sd->wake_idx; do { - unsigned long load, avg_load; + unsigned long load, avg_load, cpu_capacity; int local_group; int i; @@ -4680,6 +4681,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, /* Tally up the load of all CPUs in the group */ avg_load = 0; + cpu_capacity = 0; for_each_cpu(i, sched_group_cpus(group)) { /* Bias balancing toward cpus of our domain */ @@ -4689,6 +4691,9 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, load = target_load(i, load_idx); avg_load += load; + + if (cpu_capacity < capacity_of(i)) + cpu_capacity = capacity_of(i); } /* Adjust by relative CPU capacity of the group */ @@ -4696,14 +4701,20 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, if (local_group) { this_load = avg_load; + this_cpu_cap = cpu_capacity; } else if (avg_load < min_load) { min_load = avg_load; idlest = group; + idlest_cpu_cap = cpu_capacity; } } while (group = group->next, group != sd->groups); - if (!idlest || 100*this_load < imbalance*min_load) + if (!idlest) + return NULL; + + if (100*this_load < imbalance*min_load && this_cpu_cap >= idlest_cpu_cap) return NULL; + return idlest; } |