Re: [PATCH 2/6] perf/x86: Fix data source decoding for Skylake

From: Peter Zijlstra
Date: Tue Jun 06 2017 - 12:21:18 EST


On Tue, Jun 06, 2017 at 06:51:20AM -0700, Andi Kleen wrote:
> > Not too happy about that..
> >
> > P(LVLX, L4) | P(LVLX, REMOTE)
> >
> > reads like something that should be PERF_MEM_LVL_REM_CCE1 or something
>
> CCE1? You mean L4?

#define PERF_MEM_LVL_REM_CCE1 0x400 /* Remote Cache (1 hop) */

It says 'cache' which is irrespective of level.

> The two bits seem cleaner to me than enumerating all cases. But ok.

I tend to agree that a separate remote,distance,type fields would have
been nicer, but we seem to be stuck with this REM_* crud..

> > This new generic 'REMOTE' has too much overlap with the existing things.
>
> So you want a REM_NA ?

Not sure... What's the point of a REM_NA vs regular NA ? "'something'
happened 'not here'" vs "'something' happened".


I hope Stephane has better ideas, he seems to be the one that introduced
this in the first place.