Re: [REGRESSION] x86, perf: counter freezing breaks rr

Peter Zijlstra
2018-11-29T15:35:37Z

On Tue, Nov 27, 2018 at 03:36:15PM -0800, Andi Kleen wrote:
> > It does seem that FREEZE_PERFMON_ON_PMI (misnamed as it is) is of
> > rather limited use (or even negative, in our case) to a counter that's
> > already restricted to ring 3.
>
> It's much faster. The PMI cost goes down dramatically.

faster doesn't mean much when its broken.