On Mon, Jan 25, 2021 at 10:45:06AM +0000, Suzuki K Poulose wrote:
On 1/25/21 10:25 AM, Peter Zijlstra wrote:
Since we have a whole u64, do we want to reserve a whole nibble (or maybe even a byte) for a format type? Because with a single bit like this, we'll kick ourselves when we end up with the need for a 3rd format type.
Sure, makes sense. We could do:
#define PERF_AUX_FLAG_PMU_FORMAT_TYPE_MASK 0xff00
Additionally, the values could be allocated by individual PMUs and interpreted by the corresponding counterpart. That way we don't have to worry about centralized allocation of the "TYPE" fields.
e,g:
#define PERF_AUX_FLAG_CORESIGHT_FORMAT_CORESIGHT 0x0000 #define PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW 0x0100
#define PERF_AUX_FLAG_RANDOM_PMU_FORMAT_FMT1 0x0000 #define PERF_AUX_FLAG_RANDOM_PMU_FORMAT_FMT2 0x0100
What do you think ?
Sounds good to me.