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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c62
1 files changed, 41 insertions, 21 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index dc61e82faad..881a94474d7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -499,6 +499,9 @@ __acquires(kernel_lock)
else
if (!type->flags->opts)
type->flags->opts = dummy_tracer_opt;
+ if (!type->wait_pipe)
+ type->wait_pipe = default_wait_pipe;
+
#ifdef CONFIG_FTRACE_STARTUP_TEST
if (type->selftest && !tracing_selftest_disabled) {
@@ -1064,7 +1067,10 @@ tracing_sched_wakeup_trace(struct trace_array *tr,
entry->next_prio = wakee->prio;
entry->next_state = wakee->state;
entry->next_cpu = task_cpu(wakee);
- trace_buffer_unlock_commit(tr, event, flags, pc);
+
+ ring_buffer_unlock_commit(tr->buffer, event);
+ ftrace_trace_stack(tr, flags, 6, pc);
+ ftrace_trace_userstack(tr, flags, pc);
}
void
@@ -2392,6 +2398,38 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table)
}
}
+
+void default_wait_pipe(struct trace_iterator *iter)
+{
+ DEFINE_WAIT(wait);
+
+ prepare_to_wait(&trace_wait, &wait, TASK_INTERRUPTIBLE);
+
+ if (trace_empty(iter))
+ schedule();
+
+ finish_wait(&trace_wait, &wait);
+}
+
+/*
+ * This is a make-shift waitqueue.
+ * A tracer might use this callback on some rare cases:
+ *
+ * 1) the current tracer might hold the runqueue lock when it wakes up
+ * a reader, hence a deadlock (sched, function, and function graph tracers)
+ * 2) the function tracers, trace all functions, we don't want
+ * the overhead of calling wake_up and friends
+ * (and tracing them too)
+ *
+ * Anyway, this is really very primitive wakeup.
+ */
+void poll_wait_pipe(struct trace_iterator *iter)
+{
+ set_current_state(TASK_INTERRUPTIBLE);
+ /* sleep for 100 msecs, and try again. */
+ schedule_timeout(HZ / 10);
+}
+
/* Must be called with trace_types_lock mutex held. */
static int tracing_wait_pipe(struct file *filp)
{
@@ -2403,30 +2441,14 @@ static int tracing_wait_pipe(struct file *filp)
return -EAGAIN;
}
- /*
- * This is a make-shift waitqueue. The reason we don't use
- * an actual wait queue is because:
- * 1) we only ever have one waiter
- * 2) the tracing, traces all functions, we don't want
- * the overhead of calling wake_up and friends
- * (and tracing them too)
- * Anyway, this is really very primitive wakeup.
- */
- set_current_state(TASK_INTERRUPTIBLE);
- iter->tr->waiter = current;
-
mutex_unlock(&trace_types_lock);
- /* sleep for 100 msecs, and try again. */
- schedule_timeout(HZ/10);
+ iter->trace->wait_pipe(iter);
mutex_lock(&trace_types_lock);
- iter->tr->waiter = NULL;
-
- if (signal_pending(current)) {
+ if (signal_pending(current))
return -EINTR;
- }
if (iter->trace != current_trace)
return 0;
@@ -2442,8 +2464,6 @@ static int tracing_wait_pipe(struct file *filp)
*/
if (!tracer_enabled && iter->pos)
break;
-
- continue;
}
return 1;