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>
This commit is contained in:
Peter Zijlstra 2016-01-26 12:15:37 +01:00 committed by Ingo Molnar
parent a0733e695b
commit 07c4a77613

View File

@ -1086,8 +1086,8 @@ static void put_ctx(struct perf_event_context *ctx)
* 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
*/