Re: [PATCH] perf_events: fix bogus warn_on(_once) in perf_prepare_sample()

From: Stephane Eranian
Date: Thu Apr 08 2010 - 17:22:18 EST


On Thu, Apr 8, 2010 at 11:17 PM, Frederic Weisbecker <fweisbec@xxxxxxxxx> 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@xxxxxxxxxxxxx> 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.
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