Re: [PATCH v5 07/20] perf: Add api for pmus to write to AUX area

[Alexander Shishkin]

Peter Zijlstra <peterz@xxxxxxxxxxxxx> writes:

> On Mon, Oct 13, 2014 at 04:45:35PM +0300, Alexander Shishkin wrote:
>> +	/*
>> +	 * Nesting is not supported for AUX area, make sure nested
>> +	 * writers are caught early
>> +	 */
>> +	if (WARN_ON_ONCE(local_xchg(&rb->aux_nest, 1)))
>> +		goto err_put;
>
> Note that printk() from NMI is prone to making your machine die, not
> that I have a better option though.

Indeed, but if your driver is really attempting nested
perf_aux_output_begin()s, then you had it coming to you anyway.

Regards,
--
Alex
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