Re: [PATCH 3/6] perf: add reference time event

[Frederic Weisbecker <fweisbec@gmail.com>]

On Fri, Jun 17, 2011 at 08:04:59AM -0600, David Ahern wrote:
> 
> 
> On 06/17/2011 07:32 AM, Frederic Weisbecker wrote:
> > On Tue, Jun 07, 2011 at 05:55:46PM -0600, David Ahern wrote:
> >> For initial perf_clock to time-of-day correlation.
> >>
> >> Signed-off-by: David Ahern <dsahern@gmail.com>
> >> ---
> >>  tools/perf/util/event.c   |    1 +
> >>  tools/perf/util/event.h   |    8 ++++++++
> >>  tools/perf/util/session.c |    4 ++++
> >>  tools/perf/util/session.h |    3 ++-
> >>  4 files changed, 15 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> >> index 3c1b8a6..1a89a04 100644
> >> --- a/tools/perf/util/event.c
> >> +++ b/tools/perf/util/event.c
> >> @@ -24,6 +24,7 @@ static const char *perf_event__names[] = {
> >>  	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
> >>  	[PERF_RECORD_HEADER_BUILD_ID]		= "BUILD_ID",
> >>  	[PERF_RECORD_FINISHED_ROUND]		= "FINISHED_ROUND",
> >> +	[PERF_RECORD_REFTIME]			= "REF_TIME",
> >>  };
> >>  
> >>  const char *perf_event__name(unsigned int id)
> >> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> >> index 1d7f664..f481f90 100644
> >> --- a/tools/perf/util/event.h
> >> +++ b/tools/perf/util/event.h
> >> @@ -98,6 +98,7 @@ enum perf_user_event_type { /* above any possible kernel type */
> >>  	PERF_RECORD_HEADER_TRACING_DATA		= 66,
> >>  	PERF_RECORD_HEADER_BUILD_ID		= 67,
> >>  	PERF_RECORD_FINISHED_ROUND		= 68,
> >> +	PERF_RECORD_REFTIME			= 69,
> > 
> > We would like to avoid adding more custom events like these. They were very convenient
> > but they steal the kernel event type space. They are deemed for removal in the long term.
> > 
> > Another idea to achieve what you want would be to create a new perf event header feature,
> > like HEADER_TRACE_INFO or HEADER_BUILD_ID are. Then use that to create a space in the perf
> > file to save that couple of clocks initial values.
> 
> you mean like this:
> https://lkml.org/lkml/2010/12/7/813
> 
> David

Exactly, why did you change?