Re: [PATCH 1/2] perf, tools: Document event specifications better

[Peter Zijlstra]

On Tue, Mar 22, 2016 at 08:57:35AM +0100, Jiri Olsa wrote:
> > +Events from multiple different PMUs cannot be mixed in a group.
> 
> hum, but we allow that right?
> 
> only when there's mixture of SW and HW events we move
> it all silently under HW event context

I forgot the exact details, but we put some tight restrictions on it.

SW events can indeed be added to regular HW events, and could with some
careful work be allowed on most other groups as well (but IIRC we don't
currently allow them onto things like uncore etc..).