perf: Update locking order
Update the locking order to note that ctx::lock nests inside of
child_mutex, as per:
perf_ioctl(): ctx::mutex
-> perf_event_for_each(): event::child_mutex
-> _perf_event_enable(): ctx::lock
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 024adf0..d345964 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1086,8 +1086,8 @@
* Lock order:
* task_struct::perf_event_mutex
* perf_event_context::mutex
- * perf_event_context::lock
* perf_event::child_mutex;
+ * perf_event_context::lock
* perf_event::mmap_mutex
* mmap_sem
*/
