[PATCH 05/12] sched: Use TASK_WAKING for fork wakups

From: Peter Zijlstra
Date: Wed Dec 16 2009 - 12:06:39 EST


For later convenience use TASK_WAKING for fresh tasks.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
kernel/sched.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

Index: linux-2.6/kernel/sched.c
===================================================================
--- linux-2.6.orig/kernel/sched.c
+++ linux-2.6/kernel/sched.c
@@ -2544,14 +2544,6 @@ static void __sched_fork(struct task_str
#ifdef CONFIG_PREEMPT_NOTIFIERS
INIT_HLIST_HEAD(&p->preempt_notifiers);
#endif
-
- /*
- * We mark the process as running here, but have not actually
- * inserted it onto the runqueue yet. This guarantees that
- * nobody will actually run it, and a signal or other external
- * event cannot wake it up and insert it on the runqueue either.
- */
- p->state = TASK_RUNNING;
}

/*
@@ -2562,6 +2554,12 @@ void sched_fork(struct task_struct *p, i
int cpu = get_cpu();

__sched_fork(p);
+ /*
+ * We mark the process as waking here. This guarantees that
+ * nobody will actually run it, and a signal or other external
+ * event cannot wake it up and insert it on the runqueue either.
+ */
+ p->state = TASK_WAKING;

/*
* Revert to default priority/policy on fork if requested.
@@ -2630,7 +2628,8 @@ void wake_up_new_task(struct task_struct
struct rq *rq;

rq = task_rq_lock(p, &flags);
- BUG_ON(p->state != TASK_RUNNING);
+ BUG_ON(p->state != TASK_WAKING);
+ p->state = TASK_RUNNING;
update_rq_clock(rq);
activate_task(rq, p, 0);
trace_sched_wakeup_new(rq, p, 1);
@@ -6992,6 +6991,7 @@ void __cpuinit init_idle(struct task_str
raw_spin_lock_irqsave(&rq->lock, flags);

__sched_fork(idle);
+ idle->state = TASK_RUNNING;
idle->se.exec_start = sched_clock();

cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu));

--

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