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Subject[patch 05/30] 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>
---
kernel/irq/irqdesc.c | 4 ++--
kernel/irq/proc.c | 5 +++--
2 files changed, 5 insertions(+), 4 deletions(-)

--- a/kernel/irq/irqdesc.c
+++ b/kernel/irq/irqdesc.c
@@ -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;
}

--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -488,9 +488,10 @@ int show_interrupts(struct seq_file *p,
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;
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