Commit 95ed57c7 authored by Yury Norov's avatar Yury Norov Committed by Will Deacon
Browse files

perf: replace bitmap_weight with bitmap_empty where appropriate 



In some places, drivers/perf code calls bitmap_weight() to check if any
bit of a given bitmap is set. It's better to use bitmap_empty() in that
case because bitmap_empty() stops traversing the bitmap as soon as it
finds first set bit, while bitmap_weight() counts all bits unconditionally.

Signed-off-by: default avatarYury Norov <yury.norov@gmail.com>
Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220210224933.379149-13-yury.norov@gmail.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 602c873e

drivers/perf/arm-cci.c

+1 −1
Original line number Diff line number Diff line
@@ -1096,7 +1096,7 @@ static void cci_pmu_enable(struct pmu *pmu) 
{

	struct cci_pmu *cci_pmu = to_cci_pmu(pmu);

	struct cci_pmu_hw_events *hw_events = &cci_pmu->hw_events;

	int enabled = bitmap_weight(hw_events->used_mask, cci_pmu->num_cntrs);

	bool enabled = !bitmap_empty(hw_events->used_mask, cci_pmu->num_cntrs);

	unsigned long flags;



	if (!enabled)

drivers/perf/arm_pmu.c

+2 −2
Original line number Diff line number Diff line
@@ -524,7 +524,7 @@ static void armpmu_enable(struct pmu *pmu) 
{

	struct arm_pmu *armpmu = to_arm_pmu(pmu);

	struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);

	int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);

	bool enabled = !bitmap_empty(hw_events->used_mask, armpmu->num_events);



	/* For task-bound events we may be called on other CPUs */

	if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus))
@@ -785,7 +785,7 @@ static int cpu_pm_pmu_notify(struct notifier_block *b, unsigned long cmd, 
{

	struct arm_pmu *armpmu = container_of(b, struct arm_pmu, cpu_pm_nb);

	struct pmu_hw_events *hw_events = this_cpu_ptr(armpmu->hw_events);

	int enabled = bitmap_weight(hw_events->used_mask, armpmu->num_events);

	bool enabled = !bitmap_empty(hw_events->used_mask, armpmu->num_events);



	if (!cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus))

		return NOTIFY_DONE;

drivers/perf/hisilicon/hisi_uncore_pmu.c

+1 −1
Original line number Diff line number Diff line
@@ -393,7 +393,7 @@ EXPORT_SYMBOL_GPL(hisi_uncore_pmu_read); 
void hisi_uncore_pmu_enable(struct pmu *pmu)

{

	struct hisi_pmu *hisi_pmu = to_hisi_pmu(pmu);

	int enabled = bitmap_weight(hisi_pmu->pmu_events.used_mask,

	bool enabled = !bitmap_empty(hisi_pmu->pmu_events.used_mask,

				    hisi_pmu->num_counters);



	if (!enabled)

drivers/perf/xgene_pmu.c

+1 −1
Original line number Diff line number Diff line
@@ -867,7 +867,7 @@ static void xgene_perf_pmu_enable(struct pmu *pmu) 
{

	struct xgene_pmu_dev *pmu_dev = to_pmu_dev(pmu);

	struct xgene_pmu *xgene_pmu = pmu_dev->parent;

	int enabled = bitmap_weight(pmu_dev->cntr_assign_mask,

	bool enabled = !bitmap_empty(pmu_dev->cntr_assign_mask,

			pmu_dev->max_counters);



	if (!enabled)