ftrace: fix wakeups

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 11 insertions, 4 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 65173b14b914..2ca9d66aa74e 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -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