[PATCH V4 14/25] perf/x86: Remove temporary pmu assignment in event_init

[kan . liang]

From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The temporary pmu assignment in event_init is unnecessary.

The assignment was introduced by commit 8113070d6639 ("perf_events:
Add fast-path to the rescheduling code"). At that time, event->pmu is
not assigned yet when initializing an event. The assignment is required.
However, from commit 7e5b2a01d2ca ("perf: provide PMU when initing
events"), the event->pmu is provided before event_init is invoked.
The temporary pmu assignment in event_init should be removed.

Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
 arch/x86/events/core.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index b79a506..9c931ec 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2299,7 +2299,6 @@ static int validate_group(struct perf_event *event)
 
 static int x86_pmu_event_init(struct perf_event *event)
 {
-	struct pmu *tmp;
 	int err;
 
 	switch (event->attr.type) {
@@ -2314,20 +2313,10 @@ static int x86_pmu_event_init(struct perf_event *event)
 
 	err = __x86_pmu_event_init(event);
 	if (!err) {
-		/*
-		 * we temporarily connect event to its pmu
-		 * such that validate_group() can classify
-		 * it as an x86 event using is_x86_event()
-		 */
-		tmp = event->pmu;
-		event->pmu = &pmu;
-
 		if (event->group_leader != event)
 			err = validate_group(event);
 		else
 			err = validate_event(event);
-
-		event->pmu = tmp;
 	}
 	if (err) {
 		if (event->destroy)
-- 
2.7.4