Re: [PATCH 1/5] Add ID and STREAM_ID to recorded event data

[Eric B Munson]

On Tue, 02 Mar 2010, Peter Zijlstra wrote:

> On Tue, 2010-03-02 at 14:42 +0000, Eric B Munson wrote:
> > Currently perf record does not write the ID or the STREAM_ID to disk
> > for events.  This doesn't allow report to tell if an event stream contains
> > one or more types of events.  This patch adds these two entries to the list
> > of data that record will write to disk.
> > 
> > Signed-off-by: Eric B Munson <ebmunson@xxxxxxxxxx>
> > ---
> >  tools/perf/builtin-record.c |    3 ++-
> >  1 files changed, 2 insertions(+), 1 deletions(-)
> > 
> > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
> > index 771533c..35e4605 100644
> > --- a/tools/perf/builtin-record.c
> > +++ b/tools/perf/builtin-record.c
> > @@ -242,7 +242,8 @@ static void create_counter(int counter, int cpu, pid_t pid)
> >  				  PERF_FORMAT_TOTAL_TIME_RUNNING |
> >  				  PERF_FORMAT_ID;
> >  
> > -	attr->sample_type	|= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
> > +	attr->sample_type	|= PERF_SAMPLE_IP | PERF_SAMPLE_TID |
> > +				   PERF_SAMPLE_ID | PERF_SAMPLE_STREAM_ID;
> >  
> >  	if (freq) {
> >  		attr->sample_type	|= PERF_SAMPLE_PERIOD;
> 
> can we make this conditional on there being more than one event, that
> saves a little space/time when recording
> 

The downside to this is report cannot print the name of the event being monitored
if we do not record the sample and stream id.  This is as report behaves currently
and if that is okay then I will put out V2 with that included today.

-- 
Eric B Munson
IBM Linux Technology Center
ebmunson@xxxxxxxxxx

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