Messages in this thread | | | Date | Tue, 27 Feb 2024 15:48:27 +0800 | Subject | Re: [PATCHv10 3/4] genirq: Avoid summation loops for /proc/interrupts | From | Liu Song <> |
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在 2024/2/26 10:09, Bitao Hu 写道: > We could use the irq_desc::tot_count member to avoid the summation > loop for interrupts which are not marked as 'PER_CPU' interrupts in > 'show_interrupts'. This could reduce the time overhead of reading > /proc/interrupts. > > Originally-by: Thomas Gleixner <tglx@linutronix.de> > Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> > --- > include/linux/irqdesc.h | 2 ++ > kernel/irq/irqdesc.c | 2 +- > kernel/irq/proc.c | 9 +++++++-- > 3 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h > index 2912b1998670..1ee96d7232b4 100644 > --- a/include/linux/irqdesc.h > +++ b/include/linux/irqdesc.h > @@ -121,6 +121,8 @@ static inline void irq_unlock_sparse(void) { } > extern struct irq_desc irq_desc[NR_IRQS]; > #endif > > +extern bool irq_is_nmi(struct irq_desc *desc); > + > static inline unsigned int irq_desc_kstat_cpu(struct irq_desc *desc, > unsigned int cpu) > { > diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c > index 9cd17080b2d8..56a767957a9d 100644 > --- a/kernel/irq/irqdesc.c > +++ b/kernel/irq/irqdesc.c > @@ -955,7 +955,7 @@ unsigned int kstat_irqs_cpu(unsigned int irq, int cpu) > return desc && desc->kstat_irqs ? per_cpu(desc->kstat_irqs->cnt, cpu) : 0; > } > > -static bool irq_is_nmi(struct irq_desc *desc) > +bool irq_is_nmi(struct irq_desc *desc) > { > return desc->istate & IRQS_NMI; > } > diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c > index 6954e0a02047..b3b1b93f0410 100644 > --- a/kernel/irq/proc.c > +++ b/kernel/irq/proc.c > @@ -489,8 +489,13 @@ int show_interrupts(struct seq_file *p, void *v) > goto outsparse; > > if (desc->kstat_irqs) { > - for_each_online_cpu(j) > - any_count |= data_race(per_cpu(desc->kstat_irqs->cnt, j)); > + if (!irq_settings_is_per_cpu_devid(desc) && > + !irq_settings_is_per_cpu(desc) && > + !irq_is_nmi(desc)) > + any_count = data_race(desc->tot_count); > + else > + for_each_online_cpu(j) > + any_count |= data_race(per_cpu(desc->kstat_irqs->cnt, j)); > } > > if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
The modification borrows from the implementation of |kstat_irqs. Looks good.|
|Reviewed-by: Liu Song <liusong@linux.alibaba.com> |
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