Messages in this thread | | | Date | Thu, 8 Apr 2010 23:46:18 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH] perf_events: fix bogus warn_on(_once) in perf_prepare_sample() |
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On Thu, Apr 08, 2010 at 11:22:05PM +0200, Stephane Eranian wrote: > On Thu, Apr 8, 2010 at 11:17 PM, Frederic Weisbecker <fweisbec@gmail.com> wrote: > > On Thu, Apr 08, 2010 at 11:14:15PM +0200, Stephane Eranian wrote: > >> On Thu, Apr 8, 2010 at 11:11 PM, Peter Zijlstra <peterz@infradead.org> wrote: > >> > On Thu, 2010-04-08 at 23:08 +0200, Stephane Eranian wrote: > >> >> > >> >> Are you suggesting you add some padding the PEBS raw sample you > >> >> return as PERF_SAMPLE_RAW? Then you need to define what RAW > >> >> actually means? Seems here, it would mean more than what the > >> >> HW returns. > >> > > >> > Well, RAW doesn't mean anything much at all, its really a fugly pass > >> > some crap around thing. > >> > > >> > So yeah, adding padding seems just fine. > >> > > >> I would rather see size as u64. Who's using raw today anyway? > > > > > > The trace events. Hence the size of the size shouldn't be touched, it > > is an ABI now. > > Given your alignment constraints, it seems like it was a bad choice to pick > u32 for size to begin with.
Ah I remember now how we did that. We align the trace events raw sample size such that sizeof(raw_sample) + sizeof(size) is aligned to u64.
Well, indeed that complexifies a bit the raw_sample size handling but at least it makes the traces a bit more compact.
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