Messages in this thread | | | Date | Tue, 7 Jan 2014 21:51:45 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v0 04/71] itrace: Infrastructure for instruction flow tracing units |
| |
On Tue, Jan 07, 2014 at 04:42:55PM +0100, Andi Kleen wrote: > > Yes; go read this: > > > > lkml.kernel.org/r/20131219125205.GT3694@twins.programming.kicks-ass.net > > Hmm, but AFAIK we're not using freeze counters on PMI today. > We just rely on the explicit disabling in the counters through the global > ctrl. > > So it should be the same as with any other PMI which also does not > automatically freeze. Not true?
Regardless whether its used or not; I'd very much like that answered.
> Or do you mean interaction with the LBRs here? > (currently LBRs and PT are mutually exclusive)
Yes we very much rely on the FREEZE bits for LBR. PT and LBR being mutually exclusive wasn't documented (or I missed it) and completely blows.
| |