Messages in this thread |  | | Date | Fri, 11 Feb 2022 18:27:56 +0100 | Subject | Re: [PATCH 12/49] perf: replace bitmap_weight with bitmap_empty where appropriate | From | Christophe JAILLET <> |
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Le 10/02/2022 à 23:48, Yury Norov a écrit : > 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: Yury Norov <yury.norov@gmail.com> > --- > drivers/perf/arm-cci.c | 2 +- > drivers/perf/arm_pmu.c | 4 ++-- > drivers/perf/hisilicon/hisi_uncore_pmu.c | 2 +- > drivers/perf/xgene_pmu.c | 2 +- > 4 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/drivers/perf/arm-cci.c b/drivers/perf/arm-cci.c > index 54aca3a62814..96e09fa40909 100644 > --- a/drivers/perf/arm-cci.c > +++ b/drivers/perf/arm-cci.c > @@ -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) > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index 295cc7952d0e..a31b302b0ade 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c > @@ -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; > diff --git a/drivers/perf/hisilicon/hisi_uncore_pmu.c b/drivers/perf/hisilicon/hisi_uncore_pmu.c > index a738aeab5c04..358e4e284a62 100644 > --- a/drivers/perf/hisilicon/hisi_uncore_pmu.c > +++ b/drivers/perf/hisilicon/hisi_uncore_pmu.c > @@ -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) > diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c > index 5283608dc055..0c32dffc7ede 100644 > --- a/drivers/perf/xgene_pmu.c > +++ b/drivers/perf/xgene_pmu.c > @@ -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);
Would it make sense to call it 'disabled', remove the "!"...
> > if (!enabled) ... and 'if (disabled)' here?
Just my 2c,
CJ
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