Re: [PATCH 2/2] perf intel-pt: Use aux_watermark

From: Alexander Shishkin
Date: Wed Apr 14 2021 - 11:52:40 EST


Adrian Hunter <adrian.hunter@xxxxxxxxx> writes:

> On 8/04/21 6:31 pm, Alexander Shishkin wrote:
>> diff --git a/tools/perf/arch/x86/util/intel-pt.c b/tools/perf/arch/x86/util/intel-pt.c
>> index a6420c647959..d00707faf547 100644
>> --- a/tools/perf/arch/x86/util/intel-pt.c
>> +++ b/tools/perf/arch/x86/util/intel-pt.c
>> @@ -776,6 +776,10 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
>> }
>> }
>>
>> + if (opts->full_auxtrace)
>> + intel_pt_evsel->core.attr.aux_watermark =
>> + opts->auxtrace_mmap_pages / 4 * page_size;
>> +
>
> I would be explicit about the mode and put "/ 4" at the end
> for the case auxtrace_mmap_pages is not a multiple of 4 (e.g. 2).
> i.e.
>
> if (!opts->auxtrace_snapshot_mode && !opts->auxtrace_sample_mode) {
> u32 aux_watermark = opts->auxtrace_mmap_pages * page_size / 4;
>
> intel_pt_evsel->core.attr.aux_watermark = aux_watermark;
> }

Thank you! I'll do exactly that.

Regards,
--
Alex