perf/core: Invert perf_read_group() loops
authorPeter Zijlstra <peterz@infradead.org>
Fri, 4 Sep 2015 03:07:49 +0000 (20:07 -0700)
committerIngo Molnar <mingo@kernel.org>
Sun, 13 Sep 2015 09:27:27 +0000 (11:27 +0200)
commitfa8c269353d560b7c28119ad7617029f92e40b15
tree763677029c81e8c1e512627477b68cab02ddbe1a
parent0492d4c5b8c4dc3a7591bf6fa0e35d117812cc85
perf/core: Invert perf_read_group() loops

In order to enable the use of perf_event_read(.group = true), we need
to invert the sibling-child loop nesting of perf_read_group().

Currently we iterate the child list for each sibling, this precludes
using group reads. Flip things around so we iterate each group for
each child.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[ Made the patch compile and things. ]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
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>
Link: http://lkml.kernel.org/r/1441336073-22750-7-git-send-email-sukadev@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/events/core.c