| Message ID | 20220210224933.379149-13-yury.norov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
Hi Yury, On Thu, Feb 10, 2022 at 02:48:56PM -0800, Yury Norov wrote: > 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> This looks like a nice semantic cleanup to me, so FWIW: Acked-by: Mark Rutland <mark.rutland@arm.com> How are you expecting to queue all of this? Should Will and I pick this patch? Thanks, Mark. > --- > 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); > > if (!enabled) > -- > 2.32.0 >
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
On Fri, Feb 11, 2022 at 10:25:23AM +0000, Mark Rutland wrote: > Hi Yury, > > On Thu, Feb 10, 2022 at 02:48:56PM -0800, Yury Norov wrote: > > 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> > > This looks like a nice semantic cleanup to me, so FWIW: Thanks :) > Acked-by: Mark Rutland <mark.rutland@arm.com> > > How are you expecting to queue all of this? I expect maintainers of corresponding subsystems will pick most of the material. For the rest, I have my own bitmap branch. > Should Will and I pick this patch? Yes please. > Thanks, > Mark. > > > --- > > 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); > > > > if (!enabled) > > -- > > 2.32.0 > >
On Fri, Feb 11, 2022 at 06:27:56PM +0100, Christophe JAILLET wrote: > 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? People like positive names (as I do): $ git grep bool | grep "= \!" | grep -v "= \!\!" | wc -l 334 And probably authors chose positive name in this case for a reason. Replacing 'enabled' with 'disabled' just to avoid negation will add absolutely nothing to performance, neither to readability. But noise level of this and other patches will increase - just for nothing. For me it sounds like total negative commitment. Thanks, Yury
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); if (!enabled)
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(-)