Re: [PATCH] x86/tsc: Add debugfs entry to mark TSC as unstable after boot
From: Borislav Petkov
Date: Mon Mar 17 2025 - 10:42:35 EST
On Wed, Feb 26, 2025 at 10:27:13AM -0300, Guilherme G. Piccoli wrote:
> Right now, we can force the TSC to be marked as unstable through
Who's "we"?
> boot parameter. There are debug / test cases though in which would
Which are those test cases?
> be preferable to simulate the clocksource watchdog behavior, i.e.,
> marking TSC as unstable during the system run. Some paths might
> change, for example: the tracing clock is auto switched to global
> if TSC is marked as unstable on boot, but it could remain local if
> TSC gets marked as unstable after tracing initialization.
>
> Hence, the proposal here is to have a simple debugfs file that
> gets TSC marked as unstable when written.
What happens if someone marks the TSC as unstable and comes reporting to us
that her/his machine is kaputt? And we go on a wild goose chase ...
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette