linux-kernel - Re: [PATCH] x86/tsc: Add debugfs entry to mark TSC as unstable after boot

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Message-ID: <1238b1d0-275c-9117-a2e3-5e7684404980@igalia.com>
Date: Mon, 17 Mar 2025 11:35:45 -0300
From: "Guilherme G. Piccoli" <gpiccoli@...lia.com>
To: x86@...nel.org, linux-kernel@...r.kernel.org
Cc: tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, hpa@...or.com, kernel@...ccoli.net,
 kernel-dev@...lia.com
Subject: Re: [PATCH] x86/tsc: Add debugfs entry to mark TSC as unstable after
 boot

On 26/02/2025 10:27, Guilherme G. Piccoli wrote:
> Right now, we can force the TSC to be marked as unstable through
> boot parameter. There are debug / test cases though in which would
> 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.
> 
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@...lia.com>
> ---
>  arch/x86/kernel/tsc.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)

Hi folks, gentle ping about this one - any suggestions?
Cheers,

Guilherme