Re: [PATCH] perf/x86/amd: Make HW_CACHE_REFERENCES and HW_CACHE_MISSES measure L2

From: Peter Zijlstra
Date: Fri Aug 19 2016 - 09:34:32 EST


On Thu, Aug 18, 2016 at 06:25:22PM +0200, Borislav Petkov wrote:

> > > I could try to find better/more fitting event selectors on AMD...
> >
> > If you've got any other suggestions, I'm all ears.
>
> So there are no LLC events on AMD in the sense that there are no
> event selectors which always mean last-level cache and select those
> automagically, no matter whether the LLC is the L2, L3 and so on,
> depending on the part.
>
> If we have to be correct on AMD, we'd have to check whether the part has
> an L3 and then choose the L3 events, say, something like
>
> "EventSelect 4E1h L3 Cache Misses" and "EventSelect 4E2h L3 Fills caused
> by L2 Evictions"

Can't those events are NB events and cannot be used on per CPU counters.

The 7D,7E L2 events are the best that are available on AMD afaict.