perf: Cleanup {start,commit,cancel}_txn details

Clarify some of the transactional group scheduling API details
and change it so that a successfull ->commit_txn also closes
the transaction.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1274803086.5882.1752.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 8 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 227ed9c8ec34..6f60920772b3 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -675,7 +675,6 @@ group_sched_in(struct perf_event *group_event,
         struct perf_event *event, *partial_group = NULL;
         const struct pmu *pmu = group_event->pmu;
         bool txn = false;
-        int ret;
 
         if (group_event->state == PERF_EVENT_STATE_OFF)
                 return 0;
@@ -703,15 +702,9 @@ group_sched_in(struct perf_event *group_event,
                 }
         }
 
-        if (!txn)
+        if (!txn || !pmu->commit_txn(pmu))
                 return 0;
 
-        ret = pmu->commit_txn(pmu);
-        if (!ret) {
-                pmu->cancel_txn(pmu);
-                return 0;
-        }
-
 group_error:
         /*
          * Groups can be scheduled in as one unit only, so undo any