Re: [PATCH -v2] perf, x86: try to handle unknown nmis with running perfctrs

Cyrill Gorcunov
2010-08-16T19:18:50Z

On Mon, Aug 16, 2010 at 09:13:16PM +0200, Peter Zijlstra wrote:
> On Mon, 2010-08-16 at 23:06 +0400, Cyrill Gorcunov wrote:
> > I never heard of backward running tsc, though tsc is a strange beast.
> >
> Its not supposed to happen, but then there's BIOS failure-add that frobs
> the TSC from SMIs and fun TSC artifacts around CPU frequency changes and
> people resetting TSC in S-states etc..

grr :/

>
> In short, never trust the TSC to be even remotely sane.
>

ok, good to know, thanks!

-- Cyrill