diff options
| author | Morten Rasmussen <morten.rasmussen@arm.com> | 2016-10-14 14:41:09 +0100 |
|---|---|---|
| committer | Andres Oportus <andresoportus@google.com> | 2017-06-02 08:01:52 -0700 |
| commit | 60cc9f4e1e9fa3e951fb5a04d420da6eeb3067ee (patch) | |
| tree | 7f01f44018f36da254df1ac0ffcf42b88a23761e /kernel | |
| parent | f3f132b8e5503e750c2b89de83c3191e58798170 (diff) | |
UPSTREAM: sched/fair: Add per-CPU min capacity to sched_group_capacity
struct sched_group_capacity currently represents the compute capacity
sum of all CPUs in the sched_group.
Unless it is divided by the group_weight to get the average capacity
per CPU, it hides differences in CPU capacity for mixed capacity systems
(e.g. high RT/IRQ utilization or ARM big.LITTLE).
But even the average may not be sufficient if the group covers CPUs of
different capacities.
Instead, by extending struct sched_group_capacity to indicate min per-CPU
capacity in the group a suitable group for a given task utilization can
more easily be found such that CPUs with reduced capacity can be avoided
for tasks with high utilization (not implemented by this patch).
Change-Id: If3cae1be62d01a199e752bca5abb45357d5d0fbd
Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dietmar.eggemann@arm.com
Cc: freedom.tan@mediatek.com
Cc: keita.kobayashi.ym@renesas.com
Cc: mgalbraith@suse.de
Cc: sgurrappadi@nvidia.com
Cc: vincent.guittot@linaro.org
Cc: yuyang.du@intel.com
Link: http://lkml.kernel.org/r/1476452472-24740-4-git-send-email-morten.rasmussen@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
(cherry picked from commit bf475ce0a3dd75b5d1df6c6c14ae25168caa15ac)
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 1 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 7 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 1 |
3 files changed, 8 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fcef2588712a..948ef2438606 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6459,6 +6459,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu) */ sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); sg->sgc->max_capacity = SCHED_CAPACITY_SCALE; + sg->sgc->min_capacity = SCHED_CAPACITY_SCALE; /* * Make sure the first group of this domain contains the diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 82eb26bd4361..d18e2c7b67e5 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7268,13 +7268,14 @@ skip_unlock: __attribute__ ((unused)); cpu_rq(cpu)->cpu_capacity = capacity; sdg->sgc->capacity = capacity; sdg->sgc->max_capacity = capacity; + sdg->sgc->min_capacity = capacity; } void update_group_capacity(struct sched_domain *sd, int cpu) { struct sched_domain *child = sd->child; struct sched_group *group, *sdg = sd->groups; - unsigned long capacity, max_capacity; + unsigned long capacity, max_capacity, min_capacity; unsigned long interval; interval = msecs_to_jiffies(sd->balance_interval); @@ -7288,6 +7289,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu) capacity = 0; max_capacity = 0; + min_capacity = ULONG_MAX; if (child->flags & SD_OVERLAP) { /* @@ -7318,6 +7320,7 @@ void update_group_capacity(struct sched_domain *sd, int cpu) } max_capacity = max(capacity, max_capacity); + min_capacity = min(capacity, min_capacity); } } else { /* @@ -7331,12 +7334,14 @@ void update_group_capacity(struct sched_domain *sd, int cpu) capacity += sgc->capacity; max_capacity = max(sgc->max_capacity, max_capacity); + min_capacity = min(sgc->min_capacity, min_capacity); group = group->next; } while (group != child->groups); } sdg->sgc->capacity = capacity; sdg->sgc->max_capacity = max_capacity; + sdg->sgc->min_capacity = min_capacity; } /* diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 237b0bcdd304..6bc2dd623b17 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -899,6 +899,7 @@ struct sched_group_capacity { */ unsigned long capacity; unsigned long max_capacity; /* Max per-cpu capacity in group */ + unsigned long min_capacity; /* Min per-CPU capacity in group */ unsigned long next_update; int imbalance; /* XXX unrelated to capacity but shared group state */ /* |