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Commit 017730c1 authored by Ingo Molnar's avatar Ingo Molnar Committed by Thomas Gleixner
Browse files

ftrace: fix wakeups 



Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 24cd5d11

include/linux/sched.h

+2 −0
Original line number Diff line number Diff line
@@ -246,6 +246,8 @@ extern asmlinkage void schedule_tail(struct task_struct *prev); 
extern void init_idle(struct task_struct *idle, int cpu);

extern void init_idle_bootup_task(struct task_struct *idle);



extern int runqueue_is_locked(void);



extern cpumask_t nohz_cpu_mask;

#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)

extern int select_nohz_load_balancer(int cpu);

kernel/sched.c

+18 −0
Original line number Diff line number Diff line
@@ -642,6 +642,24 @@ static inline void update_rq_clock(struct rq *rq) 
# define const_debug static const

#endif



/**

 * runqueue_is_locked

 *

 * Returns true if the current cpu runqueue is locked.

 * This interface allows printk to be called with the runqueue lock

 * held and know whether or not it is OK to wake up the klogd.

 */

int runqueue_is_locked(void)

{

	int cpu = get_cpu();

	struct rq *rq = cpu_rq(cpu);

	int ret;



	ret = spin_is_locked(&rq->lock);

	put_cpu();

	return ret;

}



/*

 * Debugging: various feature bits

 */

kernel/trace/trace.c

+11 −4
Original line number Diff line number Diff line
@@ -70,12 +70,13 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); 


unsigned long trace_flags = TRACE_ITER_PRINT_PARENT;



/*

 * FIXME: where should this be called?

 */

void trace_wake_up(void)

{

	if (!(trace_flags & TRACE_ITER_BLOCK))

	/*

	 * The runqueue_is_locked() can fail, but this is the best we

	 * have for now:

	 */

	if (!(trace_flags & TRACE_ITER_BLOCK) && !runqueue_is_locked())

		wake_up(&trace_wait);

}
@@ -657,6 +658,8 @@ trace_function(struct trace_array *tr, struct trace_array_cpu *data, 
	entry->fn.ip		= ip;

	entry->fn.parent_ip	= parent_ip;

	spin_unlock_irqrestore(&data->lock, irq_flags);



	trace_wake_up();

}



void
@@ -686,6 +689,8 @@ __trace_special(void *__tr, void *__data, 
	entry->special.arg2	= arg2;

	entry->special.arg3	= arg3;

	spin_unlock_irqrestore(&data->lock, irq_flags);



	trace_wake_up();

}



#endif
@@ -759,6 +764,8 @@ tracing_sched_wakeup_trace(struct trace_array *tr, 
	entry->ctx.next_prio	= wakee->prio;

	__trace_stack(tr, data, flags, 5);

	spin_unlock_irqrestore(&data->lock, irq_flags);



	trace_wake_up();

}



#ifdef CONFIG_FTRACE