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sched: Drop the rq argument to sched_class::select_task_rq()

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In preparation of calling select_task_rq() without rq->lock held, drop
the dependency on the rq argument.

Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110405152729.031077745@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra
2011-04-05 17:23:46 +02:00
committed by Ingo Molnar
parent 013fdb8086
commit 7608dec2ce
6 changed files with 43 additions and 29 deletions
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20
kernel/sched.c
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@@ -2195,13 +2195,15 @@ static int migration_cpu_stop(void *data);
* The task's runqueue lock must be held.
* Returns true if you have to wait for migration thread.
*/
static bool migrate_task(struct task_struct *p, struct rq *rq)
static bool need_migrate_task(struct task_struct *p)
{
/*
* If the task is not on a runqueue (and not running), then
* the next wake-up will properly place the task.
*/
return p->on_rq || task_running(rq, p);
bool running = p->on_rq || p->on_cpu;
smp_rmb(); /* finish_lock_switch() */
return running;
}
/*
@@ -2376,9 +2378,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
* The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable.
*/
static inline
int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags)
int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
{
int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags);
int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
/*
* In order not to call set_task_cpu() on a blocking task we need
@@ -2533,7 +2535,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
en_flags |= ENQUEUE_WAKING;
}
cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags);
cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags);
if (cpu != orig_cpu)
set_task_cpu(p, cpu);
__task_rq_unlock(rq);
@@ -2744,7 +2746,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
* We set TASK_WAKING so that select_task_rq() can drop rq->lock
* without people poking at ->cpus_allowed.
*/
cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0);
cpu = select_task_rq(p, SD_BALANCE_FORK, 0);
set_task_cpu(p, cpu);
p->state = TASK_RUNNING;
@@ -3474,7 +3476,7 @@ void sched_exec(void)
int dest_cpu;
rq = task_rq_lock(p, &flags);
dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0);
dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0);
if (dest_cpu == smp_processor_id())
goto unlock;
@@ -3482,7 +3484,7 @@ void sched_exec(void)
* select_task_rq() can race against ->cpus_allowed
*/
if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) &&
likely(cpu_active(dest_cpu)) && migrate_task(p, rq)) {
likely(cpu_active(dest_cpu)) && need_migrate_task(p)) {
struct migration_arg arg = { p, dest_cpu };
task_rq_unlock(rq, &flags);
@@ -5911,7 +5913,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
goto out;
dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
if (migrate_task(p, rq)) {
if (need_migrate_task(p)) {
struct migration_arg arg = { p, dest_cpu };
/* Need help from migration thread: drop lock and wait. */
__task_rq_unlock(rq);