perf/x86: Remove temporary pmu assignment in event_init

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.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/1618237865-33448-15-git-send-email-kan.liang@linux.intel.com

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 57d3fe1..ed8dcfb 100644 (file)
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -2291,7 +2291,6 @@ out:
 
 static int x86_pmu_event_init(struct perf_event *event)
 {
-       struct pmu *tmp;
        int err;
 
        switch (event->attr.type) {
@@ -2306,20 +2305,10 @@ 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)