[PATCH] perf/core: remove a meaningless pair of rcu_read_{,un}lock()
From: Yanfei Xu
Date: Wed Jun 08 2022 - 05:44:14 EST
Per the codes, this pair of rcu_read_{,un}lock() protects nothing.
Let's remove it.
Further, the variable "pmu" is safe as it is in the SRCU read-side
critical scope of "pmus_srcu" and perf_pmu_unregister() delete it
after calling synchronize_srcu.
Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxx>
---
kernel/events/core.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 950b25c3f210..36b0df6feab4 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11296,9 +11296,7 @@ static struct pmu *perf_init_event(struct perf_event *event)
}
again:
- rcu_read_lock();
pmu = idr_find(&pmu_idr, type);
- rcu_read_unlock();
if (pmu) {
if (event->attr.type != type && type != PERF_TYPE_RAW &&
!(pmu->capabilities & PERF_PMU_CAP_EXTENDED_HW_TYPE))
--
2.32.0