On 06/22/2017 09:49 PM, Ingo Molnar wrote:
> So AFAICS it's this block that is used twice:
>
>>>> + rq = task_rq_lock(p, &rf);
>>>> + p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask);
>>>> + if (unlikely((p->sched_class == &rt_sched_class ||
>>>> + p->sched_class == &dl_sched_class) &&
>>>> + p->nr_cpus_allowed > 1)) {
>>>> + if (p->sched_class == &rt_sched_class)
>>>> + task_rq(p)->rt.rt_nr_migratory++;
>>>> + else
>>>> + task_rq(p)->dl.dl_nr_migratory++;
>>>> + }
>>>> + task_rq_unlock(rq, p, &rf);
> or is there some difference I haven't noticed?
One block increases the number of migratory tasks, and the
other one decreases...
How about this version? (if it is good, I will polish it in a v2).
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ce34e4f..0f66376 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7566,10 +7566,57 @@ const u32 sched_prio_to_wmult[40] = {
#if defined(CONFIG_PREEMPT_COUNT) && defined(CONFIG_SMP)
+enum inc_dec_migratory {
+ DEC_NR_MIGRATORY = -1,
+ INC_NR_MIGRATORY = 1,
+};
+
+static inline void
+inc_dec_nr_migratory(struct task_struct *p, enum inc_dec_migratory id)
+{
+ if (unlikely((p->sched_class == &rt_sched_class ||
+ p->sched_class == &dl_sched_class) &&
+ p->nr_cpus_allowed > 1)) {
+ if (p->sched_class == &rt_sched_class)
+ task_rq(p)->rt.rt_nr_migratory += id;
+ else
+ task_rq(p)->dl.dl_nr_migratory += id;
+ }
+}
+
+static inline void
+migrate_disable_update_cpus_allowed(struct task_struct *p)
+{
+ struct rq *rq;
+ struct rq_flags rf;
+
+ p->cpus_ptr = cpumask_of(smp_processor_id());
+
+ rq = task_rq_lock(p, &rf);
+ inc_dec_nr_migratory(p, DEC_NR_MIGRATORY);
+ p->nr_cpus_allowed = 1;
+ task_rq_unlock(rq, p, &rf);
+}
+
+static inline void
+migrate_enable_update_cpus_allowed(struct task_struct *p)
+{
+ struct rq *rq;
+ struct rq_flags rf;
+
+ p->cpus_ptr = &p->cpus_mask;
+
+ rq = task_rq_lock(p, &rf);
+ p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask);
+ inc_dec_nr_migratory(p, INC_NR_MIGRATORY);
+ task_rq_unlock(rq, p, &rf);
+}
+
void migrate_disable(void)
{
struct task_struct *p = current;
+
if (in_atomic() || irqs_disabled()) {
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic++;
@@ -7593,10 +7640,9 @@ void migrate_disable(void)
preempt_disable();
preempt_lazy_disable();
pin_current_cpu();
- p->migrate_disable = 1;
- p->cpus_ptr = cpumask_of(smp_processor_id());
- p->nr_cpus_allowed = 1;
+ migrate_disable_update_cpus_allowed(p);
+ p->migrate_disable = 1;
preempt_enable();
}
@@ -7606,6 +7652,7 @@ void migrate_enable(void)
{
struct task_struct *p = current;
+
if (in_atomic() || irqs_disabled()) {
#ifdef CONFIG_SCHED_DEBUG
p->migrate_disable_atomic--;
@@ -7628,9 +7675,8 @@ void migrate_enable(void)
preempt_disable();
- p->cpus_ptr = &p->cpus_mask;
- p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask);
p->migrate_disable = 0;
+ migrate_enable_update_cpus_allowed(p);
if (p->migrate_disable_update) {
struct rq *rq;
--
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