[PATCH v2 44/44] arm64,riscv,perf: Remove RCU_NONIDLE() usage

Peter Zijlstra
2022-09-19T10:19:08Z

The PM notifiers should no longer be ran with RCU disabled (per the
previous patches), as such this hack is no longer required either.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
drivers/perf/arm_pmu.c | 11 +----------
drivers/perf/riscv_pmu_sbi.c | 8 +-------
2 files changed, 2 insertions(+), 17 deletions(-)

--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -762,17 +762,8 @@ static void cpu_pm_pmu_setup(struct arm_
case CPU_PM_ENTER_FAILED:
/*
* Restore and enable the counter.
- * armpmu_start() indirectly calls
- *
- * perf_event_update_userpage()
- *
- * that requires RCU read locking to be functional,
- * wrap the call within RCU_NONIDLE to make the
- * RCU subsystem aware this cpu is not idle from
- * an RCU perspective for the armpmu_start() call
- * duration.
*/
- RCU_NONIDLE(armpmu_start(event, PERF_EF_RELOAD));
+ armpmu_start(event, PERF_EF_RELOAD);
break;
default:
break;
--- a/drivers/perf/riscv_pmu_sbi.c
+++ b/drivers/perf/riscv_pmu_sbi.c
@@ -747,14 +747,8 @@ static int riscv_pm_pmu_notify(struct no
case CPU_PM_ENTER_FAILED:
/*
* Restore and enable the counter.
- *
- * Requires RCU read locking to be functional,
- * wrap the call within RCU_NONIDLE to make the
- * RCU subsystem aware this cpu is not idle from
- * an RCU perspective for the riscv_pmu_start() call
- * duration.
*/
- RCU_NONIDLE(riscv_pmu_start(event, PERF_EF_RELOAD));
+ riscv_pmu_start(event, PERF_EF_RELOAD);
break;
default:
break;