diff options
| author | Paul Turner <pjt@google.com> | 2012-09-21 13:27:47 -0700 |
|---|---|---|
| committer | Viresh Kumar <viresh.kumar@linaro.org> | 2012-10-08 08:52:37 +0530 |
| commit | e553b8d123721a3dc57b8a9856d754bbe93769a8 (patch) | |
| tree | 6a9a78f40d1ba68b9e909191c5a29d2b33d9ef44 | |
| parent | f174f34d6962790f636f71c9f0f916d48bf7b3c3 (diff) | |
sched: add an rq migration call-back to sched_class
Since we are now doing bottom up load accumulation we need explicit
notification when a task has been re-parented so that the old hierarchy can be
updated.
Adds: migrate_task_rq(struct task_struct *p, int next_cpu)
(The alternative is to do this out of __set_task_cpu, but it was suggested that
this would be a cleaner encapsulation.)
Signed-off-by: Paul Turner <pjt@google.com>
Reviewed-by: Ben Segall <bsegall@google.com>
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/sched/core.c | 2 | ||||
| -rw-r--r-- | kernel/sched/fair.c | 12 |
3 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index f377254521a..6446bd9f8a9 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1105,6 +1105,7 @@ struct sched_class { #ifdef CONFIG_SMP int (*select_task_rq)(struct task_struct *p, int sd_flag, int flags); + void (*migrate_task_rq)(struct task_struct *p, int next_cpu); void (*pre_schedule) (struct rq *this_rq, struct task_struct *task); void (*post_schedule) (struct rq *this_rq); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index fe3f3293b60..c106214f64b 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1109,6 +1109,8 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu) trace_sched_migrate_task(p, new_cpu); if (task_cpu(p) != new_cpu) { + if (p->sched_class->migrate_task_rq) + p->sched_class->migrate_task_rq(p, new_cpu); p->se.nr_migrations++; perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index b93f0cf1c77..973a6b8b28d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -3075,6 +3075,17 @@ unlock: return new_cpu; } + +/* + * Called immediately before a task is migrated to a new cpu; task_cpu(p) and + * cfs_rq_of(p) references at time of call are still valid and identify the + * previous cpu. However, the caller only guarantees p->pi_lock is held; no + * other assumptions, including the state of rq->lock, should be made. + */ +static void +migrate_task_rq_fair(struct task_struct *p, int next_cpu) +{ +} #endif /* CONFIG_SMP */ static unsigned long @@ -5640,6 +5651,7 @@ const struct sched_class fair_sched_class = { #ifdef CONFIG_SMP .select_task_rq = select_task_rq_fair, + .migrate_task_rq = migrate_task_rq_fair, .rq_online = rq_online_fair, .rq_offline = rq_offline_fair, |