Re: [PATCH 04/10] perf, x86: Making hardware events translations available in sysfs

[Jiri Olsa <jolsa@redhat.com>]

On Wed, Jul 04, 2012 at 12:28:58PM +0200, Peter Zijlstra wrote:
> On Wed, 2012-07-04 at 12:24 +0200, Peter Zijlstra wrote:
> > On Wed, 2012-07-04 at 00:00 +0200, Jiri Olsa wrote:
> > > +static struct attribute *events_attr[] = {
> > > +       &event_attr_cycles.attr,
> > > +       &event_attr_instructions.attr,
> > > +       &event_attr_cache_references.attr,
> > > +       &event_attr_cache_misses.attr,
> > > +       &event_attr_branch_instructions.attr,
> > > +       &event_attr_branch_misses.attr,
> > > +       &event_attr_bus_cycles.attr,
> > > +       &event_attr_stalled_cycles_frontend.attr,
> > > +       &event_attr_stalled_cycles_backend.attr,
> > > +       &event_attr_ref_cycles.attr,
> > > +       NULL,
> > > +}; 
> > 
> > Hmm, should we do:
> > 
> >   if (!config)
> >     return -EINVAL;
> > 
> > or somesuch to clearly indicate an event isn't supported?
> > 
> > Its currently a bit of a mixed bag between 0 and -1.. we might want to
> > clean that up too.
> 
> Alternatively, we'd do something like:
> 
>   for (i = 0; events_attr[i]; i++) {
>     if (x86_pmu.event_map(i))
>       continue;
> 
>     for (j = i; events_attr[j]; j++)
>       events_attr[j] = events_attr[j+1];
>   }
> 
> On init to filter out all unset events so they don't even show up in
> sysfs.
>       
> 

ok