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| author |   Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-04-05 17:23:52 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2011-04-14 08:52:38 +0200 |
| commit | ab2515c4b98f7bc4fa11cad9fa0f811d63a72a26 (patch) | |
| tree | cf70c60583a3e3dd5e6cb47193e3db9a4620608b /kernel | |
| parent | sched: Add p->pi_lock to task_rq_lock() (diff) | |
| download | linux-dev-ab2515c4b98f7bc4fa11cad9fa0f811d63a72a26.tar.xz linux-dev-ab2515c4b98f7bc4fa11cad9fa0f811d63a72a26.zip | |
sched: Drop rq->lock from first part of wake_up_new_task()
Since p->pi_lock now protects all things needed to call
select_task_rq() avoid the double remote rq->lock acquisition and rely
on p->pi_lock.
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/20110405152729.273362517@chello.nl
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 17 |
1 files changed, 3 insertions, 14 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index f1551271a685..7c5494dccd39 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2736,28 +2736,18 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) { unsigned long flags; struct rq *rq; - int cpu __maybe_unused = get_cpu(); + raw_spin_lock_irqsave(&p->pi_lock, flags); #ifdef CONFIG_SMP - rq = task_rq_lock(p, &flags); - p->state = TASK_WAKING; - /* * Fork balancing, do it here and not earlier because: * - cpus_allowed can change in the fork path * - any previously selected cpu might disappear through hotplug - * - * We set TASK_WAKING so that select_task_rq() can drop rq->lock - * without people poking at ->cpus_allowed. */ - cpu = select_task_rq(p, SD_BALANCE_FORK, 0); - set_task_cpu(p, cpu); - - p->state = TASK_RUNNING; - task_rq_unlock(rq, p, &flags); + set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); #endif - rq = task_rq_lock(p, &flags); + rq = __task_rq_lock(p); activate_task(rq, p, 0); p->on_rq = 1; trace_sched_wakeup_new(p, true); @@ -2767,7 +2757,6 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) p->sched_class->task_woken(rq, p); #endif task_rq_unlock(rq, p, &flags); - put_cpu(); } #ifdef CONFIG_PREEMPT_NOTIFIERS |