Re: [RFC PATCH] perf/stat: Add --disable-hwdt

From: Ingo Molnar
Date: Mon Feb 06 2017 - 07:44:57 EST



* Borislav Petkov <bp@xxxxxxxxx> wrote:

> On Mon, Feb 06, 2017 at 01:22:31PM +0100, Ingo Molnar wrote:
> > Looks sensible, and I'd in fact make this the new default behavior (if root runs
> > perf stat) - i.e. add a flag to re-enable it, for the rare case where we want to
> > debug a hard deadlock while running perf stat ...
>
> I'd probably only need to save the previous state, in case it was
> disabled for whatever reason.
>
> So actually, I'll make it so that we restore the previous state at exit.
> Whatever it was. But while perf stat runs as root, we will disable it by
> default.
>
> /me scratches head a bit...
>
> Oh ok, even better - no need for a cmdline option then.
>
> Or does it *ever* make sense to have watchdog running *while* perf stat
> runs too?

Yeah, if for some whatever reason perf locks up while running perf stat as root,
so I'd keep the option, as a general principle. :-/

Thanks,

Ingo