lkml.org 
[lkml]   [2015]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH V8 7/8] perf, x86: introduce PERF_RECORD_LOST_SAMPLES
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?


\
 
 \ /
  Last update: 2015-05-07 17:01    [W:0.110 / U:0.468 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site