Re: [PATCH 4/7] perf/x86-ibs: Add support for IBS pseudo events

[Peter Zijlstra]

On Mon, 2012-05-07 at 17:44 +0200, Robert Richter wrote:
> On 07.05.12 15:03:02, Peter Zijlstra wrote:
> > On Wed, 2012-05-02 at 20:26 +0200, Robert Richter wrote:
> > > +enum ibs_filter_type {
> > > +       IBS_NO_FILTER           = 0,
> > > +       IBS_MATCH_FILTER        = 1,
> > > +       IBS_ANY_SET_FILTER      = 2,
> > > +       IBS_PSEUDO_EVENT        = 0x0F,
> > > +};
> > 
> > I don't get how those pseudo events work, AFAIKT IBS_PSEUDO_EVENT causes
> > one to loose all events since it does have a filter set but fails the
> > filter and thus we skip the call to perf_event_overflow().
> 
> You periodically (fix clk cycles or number of micro-ops) trigger IBS
> samples and afterwards analyses the samples for certain filter rules
> (see rule description in pmu-ibs.c). 

But IBS_PSEUDO_EVENT will fail all filter test and you'll end up with
exactly 0 samples. Still somewhat confused..

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