Re: [PATCH 1/1] perf, Add support for Xeon-Phi PMU

From: Cyrill Gorcunov
Date: Tue Sep 25 2012 - 07:42:20 EST


On Tue, Sep 25, 2012 at 01:32:38PM +0200, Peter Zijlstra wrote:
> On Thu, 2012-09-20 at 13:03 -0400, Vince Weaver wrote:
> > One additional complication: some of the cache events map to
> > event "0". This causes problems because the generic events code
> > assumes "0" means not-available. I'm not sure the best way to address
> > that problem.
>
> For all except P4 we could remap the 0 value to -2, that has all high
> bits set (like the -1) which aren't used by hardware.
>
> P4 is stuffing two registers in the 64bit config space and actually has
> them all in use I think.. Cyrill?

Yeah, we use almost all 64 bits in config. I tried to describe the bitmaps
in perf_event_p4.h (see Notes on internal configuration of ESCR+CCCR tuples).

Guys, letme re-read this whole mail thread first since I have no clue
what this remapping about ;)
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