Re: [PATCH 7/8] xtensa: implement counting and sampling perf events

From: Max Filippov
Date: Mon Jul 06 2015 - 09:56:14 EST


On Mon, Jul 6, 2015 at 4:47 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Mon, Jul 06, 2015 at 04:32:48PM +0300, Max Filippov wrote:
>> +static int __init xtensa_pmu_init(void)
>> +{
>> + int ret;
>> + int irq = irq_create_mapping(NULL, XCHAL_PROFILING_INTERRUPT);
>
> Does this platform have interrupt priorities which you can partially
> mask in order to create NMI like behaviour?

Not sure what you mean by "NMI like".
Interrupt priorities are fixed in the current xtensa architecture, and
we can in theory
mask certain level and below, but practically we always mask all low-
and medium-
level interrupts.

Also we currently can't have handlers for high priority interrupts written in C.

--
Thanks.
-- Max
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