Re: [PATCH 1/6] perf, x86: Making hardware events tranlations sysfs available

[Jiri Olsa <jolsa@redhat.com>]

On Thu, Jun 14, 2012 at 11:36:51PM +0200, Stephane Eranian wrote:
> On Thu, Jun 14, 2012 at 11:09 PM, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> > On Thu, 2012-06-14 at 22:38 +0200, Jiri Olsa wrote:
> >> Making hardware events tranlations available throught the sysfs.
> >> Adding 'events' group attribute under the sysfs x86 PMU record
> >> with attribute/file for each hardware event:
> >>
> >>   # ls  /sys/devices/cpu/events/
> >>   branch_instructions
> >>   branch_misses
> >>   bus_cycles
> >>   cache_misses
> >>   cache_references
> >>   cycles
> >>   instructions
> >>   ref_cycles
> >>   stalled_cycles_backend
> >>   stalled_cycles_frontend
> >>
> >> The file - ID mappings is:
> >>
> >>   file                      hw id
> >>   ----------------------------------------------------------------
> >>   cycles                    PERF_COUNT_HW_CPU_CYCLES
> >>   instructions              PERF_COUNT_HW_INSTRUCTIONS
> >>   cache_references          PERF_COUNT_HW_CACHE_REFERENCES
> >>   cache_misses              PERF_COUNT_HW_CACHE_MISSES
> >>   branch_instructions       PERF_COUNT_HW_BRANCH_INSTRUCTIONS
> >>   branch_misses             PERF_COUNT_HW_BRANCH_MISSES
> >>   bus_cycles                PERF_COUNT_HW_BUS_CYCLES
> >>   stalled_cycles_frontend   PERF_COUNT_HW_STALLED_CYCLES_FRONTEND
> >>   stalled_cycles_backend    PERF_COUNT_HW_STALLED_CYCLES_BACKEND
> >>   ref_cycles                PERF_COUNT_HW_REF_CPU_CYCLES
> >>
> >> Each attribute/file contains HW ID event translation for the currently
> >> running CPU model
> >>
> >>   # cat /sys/devices/cpu/events/instructions
> >>   0xc0
> >
> > Why not have it consistent with the stuff done for uncore where events
> > read: 'event=0xc0', ie the regular field=value stuff.
> >
> Yes, you want that. Because those events may need more than a code.
> You want full syntax capability. So return a string.

humm... right :)

how about the term name 'event=...', could I always assume it's 'event',
or do we want some arch specific connection for that?

jirka