sched/topology: Rewrite get_group()
We want to attain:
sg_cpus() & sg_mask() == sg_mask()
for this to be so we must initialize sg_mask() to sg_cpus() for the
!overlap case (its currently cpumask_setall()).
Since the code makes my head hurt bad, rewrite it into a simpler form,
inspired by the now fixed overlap code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index b279083..dea1950 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -833,23 +833,34 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
* [*] in other words, the first group of each domain is its child domain.
*/
-static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
+static struct sched_group *get_group(int cpu, struct sd_data *sdd)
{
struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
struct sched_domain *child = sd->child;
+ struct sched_group *sg;
if (child)
cpu = cpumask_first(sched_domain_span(child));
- if (sg) {
- *sg = *per_cpu_ptr(sdd->sg, cpu);
- (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu);
+ sg = *per_cpu_ptr(sdd->sg, cpu);
+ sg->sgc = *per_cpu_ptr(sdd->sgc, cpu);
- /* For claim_allocations: */
- atomic_set(&(*sg)->sgc->ref, 1);
+ /* For claim_allocations: */
+ atomic_inc(&sg->ref);
+ atomic_inc(&sg->sgc->ref);
+
+ if (child) {
+ cpumask_copy(sched_group_cpus(sg), sched_domain_span(child));
+ cpumask_copy(sched_group_mask(sg), sched_group_cpus(sg));
+ } else {
+ cpumask_set_cpu(cpu, sched_group_cpus(sg));
+ cpumask_set_cpu(cpu, sched_group_mask(sg));
}
- return cpu;
+ sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sched_group_cpus(sg));
+ sg->sgc->min_capacity = SCHED_CAPACITY_SCALE;
+
+ return sg;
}
/*
@@ -868,34 +879,20 @@ build_sched_groups(struct sched_domain *sd, int cpu)
struct cpumask *covered;
int i;
- get_group(cpu, sdd, &sd->groups);
- atomic_inc(&sd->groups->ref);
-
- if (cpu != cpumask_first(span))
- return 0;
-
lockdep_assert_held(&sched_domains_mutex);
covered = sched_domains_tmpmask;
cpumask_clear(covered);
- for_each_cpu(i, span) {
+ for_each_cpu_wrap(i, span, cpu) {
struct sched_group *sg;
- int group, j;
if (cpumask_test_cpu(i, covered))
continue;
- group = get_group(i, sdd, &sg);
- cpumask_setall(sched_group_mask(sg));
+ sg = get_group(i, sdd);
- for_each_cpu(j, span) {
- if (get_group(j, sdd, NULL) != group)
- continue;
-
- cpumask_set_cpu(j, covered);
- cpumask_set_cpu(j, sched_group_cpus(sg));
- }
+ cpumask_or(covered, covered, sched_group_cpus(sg));
if (!first)
first = sg;
@@ -904,6 +901,7 @@ build_sched_groups(struct sched_domain *sd, int cpu)
last = sg;
}
last->next = first;
+ sd->groups = first;
return 0;
}
