sched: Change the ttwu() success details
Peter Zijlstra [Tue, 5 Apr 2011 15:23:42 +0000 (17:23 +0200)]
try_to_wake_up() would only return a success when it would have to
place a task on a rq, change that to every time we change p->state to
TASK_RUNNING, because that's the real measure of wakeups.

This results in that success is always true for the tracepoints.

Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
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>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20110405152728.866866929@chello.nl

kernel/sched.c

index 81ab58e..3919aa4 100644 (file)
@@ -2427,10 +2427,10 @@ static inline void ttwu_activate(struct task_struct *p, struct rq *rq,
                wq_worker_waking_up(p, cpu_of(rq));
 }
 
-static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq,
-                                       int wake_flags, bool success)
+static void
+ttwu_post_activation(struct task_struct *p, struct rq *rq, int wake_flags)
 {
-       trace_sched_wakeup(p, success);
+       trace_sched_wakeup(p, true);
        check_preempt_curr(rq, p, wake_flags);
 
        p->state = TASK_RUNNING;
@@ -2546,9 +2546,9 @@ out_activate:
 #endif /* CONFIG_SMP */
        ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu,
                      cpu == this_cpu, en_flags);
-       success = 1;
 out_running:
-       ttwu_post_activation(p, rq, wake_flags, success);
+       ttwu_post_activation(p, rq, wake_flags);
+       success = 1;
 out:
        task_rq_unlock(rq, &flags);
        put_cpu();
@@ -2567,7 +2567,6 @@ out:
 static void try_to_wake_up_local(struct task_struct *p)
 {
        struct rq *rq = task_rq(p);
-       bool success = false;
 
        BUG_ON(rq != this_rq());
        BUG_ON(p == current);
@@ -2582,9 +2581,8 @@ static void try_to_wake_up_local(struct task_struct *p)
                        schedstat_inc(rq, ttwu_local);
                }
                ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP);
-               success = true;
        }
-       ttwu_post_activation(p, rq, 0, success);
+       ttwu_post_activation(p, rq, 0);
 }
 
 /**
@@ -2747,7 +2745,7 @@ void wake_up_new_task(struct task_struct *p, unsigned long clone_flags)
 
        rq = task_rq_lock(p, &flags);
        activate_task(rq, p, 0);
-       trace_sched_wakeup_new(p, 1);
+       trace_sched_wakeup_new(p, true);
        check_preempt_curr(rq, p, WF_FORK);
 #ifdef CONFIG_SMP
        if (p->sched_class->task_woken)