[tip:perf/urgent] perf/core: Remove a redundant check

From: tip-bot for Alexander Shishkin
Date: Wed Jun 08 2016 - 10:21:20 EST


Commit-ID: 62a92c8f553e49270a0ee391b8733da71ab0aebc
Gitweb: http://git.kernel.org/tip/62a92c8f553e49270a0ee391b8733da71ab0aebc
Author: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
AuthorDate: Tue, 7 Jun 2016 15:44:15 +0300
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 8 Jun 2016 14:30:01 +0200

perf/core: Remove a redundant check

There is no way to end up in _free_event() with event::pmu being NULL.
The latter is initialized in event allocation path and remains set
forever. In case of allocation failure, the error path doesn't use
_free_event().

Having the check, however, suggests that it is possible to have a
event::pmu==NULL situation in _free_event() and confuses the robots.

This patch gets rid of the check.

Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: eranian@xxxxxxxxxx
Cc: vince@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1465303455-26032-1-git-send-email-alexander.shishkin@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/events/core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 050a290..87e945d 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3862,10 +3862,8 @@ static void _free_event(struct perf_event *event)
if (event->ctx)
put_ctx(event->ctx);

- if (event->pmu) {
- exclusive_event_destroy(event);
- module_put(event->pmu->module);
- }
+ exclusive_event_destroy(event);
+ module_put(event->pmu->module);

call_rcu(&event->rcu_head, free_event_rcu);
}