Re: [PATCH V3 14/14] coresight: etm-perf: Add support for trace buffer format

From: Anshuman Khandual
Date: Wed Feb 17 2021 - 22:06:48 EST




On 1/27/21 6:30 PM, Al Grant wrote:
>>> +/* CoreSight PMU AUX buffer formats */
>>> +#define PERF_AUX_FLAG_CORESIGHT_FORMAT_CORESIGHT0x0000 /*
>> Default for backward compatibility */
>>> +#define PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW0x0100 /*
>> Raw format of the source */
>>
>> Would CORESIGHT_FORMAT_ETR / CORESIGHT_FORMAT_TRBE be better
>> names?
>
> Unformatted (raw) streams could be used any time you had a writer dedicated
> to a single trace source. So in a situation where you had one ETR per CPU,
> it would be appropriate to use an unformatted stream. A TRBE is always
> dedicated to a single CPU, but potentially you (i.e. when designing the system)
> can do this with any type of trace sink. So the raw/formatted distinction is
> really about whether you are combining multiple streams in one buffer or not,
> rather than the type of block that is writing into the buffer.
>
> Al
>

Okay, will stick with the proposed format names here

i.e

PERF_AUX_FLAG_CORESIGHT_FORMAT_CORESIGHT
PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW