Re: perf/Documentation/ABI -- add some documentation for perf_event sysfs usage

[Jiri Olsa <jolsa@redhat.com>]

On Thu, Jul 04, 2013 at 11:02:53AM +0200, Peter Zijlstra wrote:
> On Wed, Jul 03, 2013 at 11:14:40PM -0400, Vince Weaver wrote:
> > On Wed, 3 Jul 2013, Vince Weaver wrote:
> 
> > OK, don't I feel silly, these values were already documented in 
> >    Documentation/ABI/testing/sysfs-bus-event_source-devices-events
> > rather than ABI/stable
> > 
> > To be fair I missed it because the documentation seemed to come from the 
> > Power developers and not through perf_event
> >
> > anyway, that documentation says the values will be hex only, which was 
> > broken by
> > 
> > commit f9134f36aed59ab55c0ab1a4618dd455f15aef5f
> > Author: Andi Kleen <ak@linux.intel.com>
> > Date:   Mon Jun 17 17:36:52 2013 -0700
> > 
> >     perf/x86/intel: Add mem-loads/stores support for Haswell
> > 
> > 
> > which added:
> > EVENT_ATTR_STR(mem-loads,      mem_ld_hsw,     "event=0xcd,umask=0x1,ldlat=3");
> > 
> > (note ldlat is not in hex).
> > 
> > This broke the trinity fuzzer (which scans to look for events to use)
> > as well as some of my personal tools.
> > 
> > Should the ldlat value be fixed to be hex?  Or should we ammend the ABI
> > document to allow decimal?
> 
> I don't see a good reason not to allow decimal as well. Jolsa?

yep, no technical problem with decimal

hum, the doc mentions 'event' term only, which IS hex only AFAICS ;-)

I think this docs should be updated and either describe all
allowed terms or be generic enough to cover all of them.

jirka