[PATCH v3 46/51] arm64,riscv,perf: Remove RCU_NONIDLE() usage

Peter Zijlstra
Thu, 12 Jan 2023 19:44:00 -0000

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 at infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Acked-by: Frederic Weisbecker <frederic at kernel.org>
Tested-by: Tony Lindgren <tony at atomide.com>
Tested-by: Ulf Hansson <ulf.hansson at linaro.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;