Commit 9e42ad10 authored by Thomas Gleixner's avatar Thomas Gleixner
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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: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20201210194043.067097663@linutronix.de
parent 3e238012

kernel/irq/irqdesc.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

}

kernel/irq/proc.c

+3 −2
Original line number Diff line number Diff line
@@ -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;