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
......@@ -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);
......
......@@ -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
*/
......
......@@ -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
......
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