[tip:sched/locking] sched: Change the ttwu() success details

From: tip-bot for Peter Zijlstra
Date: Thu Apr 14 2011 - 04:34:12 EST


Commit-ID: 893633817f5b58f5227365d74344e0170a718213
Gitweb: http://git.kernel.org/tip/893633817f5b58f5227365d74344e0170a718213
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Tue, 5 Apr 2011 17:23:42 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 14 Apr 2011 08:52:34 +0200

sched: Change the ttwu() success details

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@xxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20110405152728.866866929@xxxxxxxxx
---
kernel/sched.c | 16 +++++++---------
1 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 81ab58e..3919aa4 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -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)
--
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