Re: [patch/rfc] perf on raspberry-pi without overflow interrupt

[Vince Weaver]

On Thu, 9 Jan 2014, Will Deacon wrote:

> I'd rather see it in the generic code if at all possible. Maybe we could add
> a flags field to perf_pmu_register?

I can look into adding the check in generic code.

In the meantime, would you consider a patch like this that disables
the IRQ check and lets ARM devices missing an IRQ (such as the rasp-pi)
still have access to the counters?


diff --git a/arch/arm/kernel/perf_event_cpu.c b/arch/arm/kernel/perf_event_cpu.c
index d85055c..ff1a752 100644
--- a/arch/arm/kernel/perf_event_cpu.c
+++ b/arch/arm/kernel/perf_event_cpu.c
@@ -97,8 +97,8 @@ static int cpu_pmu_request_irq(struct arm_pmu *cpu_pmu, irq_handler_t handler)
 
 	irqs = min(pmu_device->num_resources, num_possible_cpus());
 	if (irqs < 1) {
-		pr_err("no irqs for PMUs defined\n");
-		return -ENODEV;
+		printk_once("no irqs for PMUs defined, sampling events not supported\n");
+		return 0;
 	}
 
 	for (i = 0; i < irqs; ++i) {

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/