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

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Message-ID: <tip-62a92c8f553e49270a0ee391b8733da71ab0aebc@git.kernel.org>
Date:	Wed, 8 Jun 2016 07:20:33 -0700
From:	tip-bot for Alexander Shishkin <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	dan.carpenter@...cle.com, mingo@...nel.org, tglx@...utronix.de,
	acme@...radead.org, hpa@...or.com, torvalds@...ux-foundation.org,
	alexander.shishkin@...ux.intel.com, peterz@...radead.org,
	linux-kernel@...r.kernel.org
Subject: [tip:perf/urgent] perf/core: Remove a redundant check

Commit-ID:  62a92c8f553e49270a0ee391b8733da71ab0aebc
Gitweb:     http://git.kernel.org/tip/62a92c8f553e49270a0ee391b8733da71ab0aebc
Author:     Alexander Shishkin <alexander.shishkin@...ux.intel.com>
AuthorDate: Tue, 7 Jun 2016 15:44:15 +0300
Committer:  Ingo Molnar <mingo@...nel.org>
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@...cle.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@...ux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Arnaldo Carvalho de Melo <acme@...radead.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: eranian@...gle.com
Cc: vince@...ter.net
Link: http://lkml.kernel.org/r/1465303455-26032-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 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);
 }