From: tip-bot for Paul Mackerras on
Commit-ID: 6e85158cf5a2385264316870256fb6ad681156a0
Author: Paul Mackerras <paulus(a)>
AuthorDate: Sat, 8 May 2010 20:58:00 +1000
Committer: Ingo Molnar <mingo(a)>
CommitDate: Sat, 8 May 2010 13:16:55 +0200

perf_event: Make software events work again

Commit 6bde9b6ce0127e2a56228a2071536d422be31336 ("perf: Add
group scheduling transactional APIs") added code to allow a
group to be scheduled in a single transaction. However, it
introduced a bug in handling events whose pmu does not implement
transactions -- at the end of scheduling in the events in the
group, in the non-transactional case the code now falls through
to the group_error label, and proceeds to unschedule all the
events in the group and return failure.

This fixes it by returning 0 (success) in the non-transactional

Signed-off-by: Paul Mackerras <paulus(a)>
Cc: Peter Zijlstra <peterz(a)>
Cc: Lin Ming <ming.m.lin(a)>
Cc: Frederic Weisbecker <fweisbec(a)>
Cc: eranian(a)
LKML-Reference: <20100508105800.GB10650(a)>
Signed-off-by: Ingo Molnar <mingo(a)>
kernel/perf_event.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index bb06382..180151f 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -664,13 +664,13 @@ group_sched_in(struct perf_event *group_event,

- if (txn) {
- ret = pmu->commit_txn(pmu);
- if (!ret) {
- pmu->cancel_txn(pmu);
+ if (!txn)
+ return 0;

- return 0;
- }
+ ret = pmu->commit_txn(pmu);
+ if (!ret) {
+ pmu->cancel_txn(pmu);
+ return 0;

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