Re: [PATCH 5/5] perf, x86: Prefer RDPMC over RDMSR for reading counters

Peter Zijlstra
2012-06-06T14:45:14Z

On Wed, 2012-06-06 at 07:41 -0700, Andi Kleen wrote:

> The reason I avoided it on everyone is that some old chips (NetBurst'ish
> I think) only were able to read the low 32bits through RDPMC.

Can you verify that? Surely Intel still has one of those space heaters
laying about. If so we need to make the P4 driver do something else.

> Ok. I wasn't aware of that. But it's not merged, what happened to ti?

I forgot about it and queued it instead of your patch, so it should be
'out' there soon.