Messages in this thread | | | Date | Thu, 7 May 2015 16:39:39 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH V8 7/8] perf, x86: introduce PERF_RECORD_LOST_SAMPLES |
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On Thu, May 07, 2015 at 11:15:20AM -0300, Arnaldo Carvalho de Melo wrote: > Em Thu, May 07, 2015 at 01:54:46PM +0200, Peter Zijlstra escreveu: > > On Thu, May 07, 2015 at 01:35:24PM +0200, Peter Zijlstra wrote: > > > > > > - dropped the @id field from the record, it is already included in the > > > @sample_id values. > > > > Hmm, this would force people to use sample_id; which in general is a > > good idea, but should we really force that on people? > > Well, if there are more than one sample, we need it, right? If there is > just one, we don't need it, what is different? Am I needing (even more) > coffee? > > /me goes read some code...
So the question was, do we do:
/* * struct { * struct perf_event_header header; * u64 id; * u64 lost; * struct sample_id sample_id; * }; */ PERF_RECORD_LOST_SAMPLES
And have the id thing twice if attr.sample_id && PERF_SAMPLE_ID, but allow decoding if !attr.sample_id.
Or force attr.sample_id && PERF_SAMPLE_ID if there's multiple events and do away with the extra id field, like:
/* * struct { * struct perf_event_header header; * u64 lost; * struct sample_id sample_id; * }; */ PERF_RECORD_LOST_SAMPLES
Should we force the use of sample_id on people?
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