tracing/function-graph-tracer: append the tracing_graph_flag
Impact: Provide a way to pause the function graph tracer
As suggested by Steven Rostedt, the previous patch that prevented from
spinlock function tracing shouldn't use the raw_spinlock to fix it.
It's much better to follow lockdep with normal spinlock, so this patch
adds a new flag for each task to make the function graph tracer able
to be paused. We also can send an ftrace_printk whithout worrying of
the irrelevant traced spinlock during insertion.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 4c152e0..4b81fc5 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1379,6 +1379,8 @@
* because of depth overrun.
*/
atomic_t trace_overrun;
+ /* Pause for the tracing */
+ atomic_t tracing_graph_pause;
#endif
#ifdef CONFIG_TRACING
/* state flags for use by tracers */