genirq: Annotate irq stats data races

Both the per cpu stats and the accumulated count are accessed lockless and
can be concurrently modified. That's intentional and the stats are a rough
estimate anyway. Annotate them with data_race().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de
This commit is contained in:
Thomas Gleixner 2020-12-10 20:25:41 +01:00
parent 3e2380123f
commit 9e42ad10ce
2 changed files with 5 additions and 4 deletions

View file

@ -943,10 +943,10 @@ unsigned int kstat_irqs(unsigned int irq)
if (!irq_settings_is_per_cpu_devid(desc) &&
!irq_settings_is_per_cpu(desc) &&
!irq_is_nmi(desc))
return desc->tot_count;
return data_race(desc->tot_count);
for_each_possible_cpu(cpu)
sum += *per_cpu_ptr(desc->kstat_irqs, cpu);
sum += data_race(*per_cpu_ptr(desc->kstat_irqs, cpu));
return sum;
}

View file

@ -488,9 +488,10 @@ int show_interrupts(struct seq_file *p, void *v)
if (!desc || irq_settings_is_hidden(desc))
goto outsparse;
if (desc->kstat_irqs)
if (desc->kstat_irqs) {
for_each_online_cpu(j)
any_count |= *per_cpu_ptr(desc->kstat_irqs, j);
any_count |= data_race(*per_cpu_ptr(desc->kstat_irqs, j));
}
if ((!desc->action || irq_desc_is_chained(desc)) && !any_count)
goto outsparse;