[RESEND PATCH v2 2/2] arm64/watchdog_hld: Add a cpufreq notifier for update watchdog thresh

[Doug Anderson]

Hi,

On Thu, Jun 19, 2025 at 4:48 AM Yicong Yang <yangyicong at huawei.com> wrote:
>
> From: Yicong Yang <yangyicong at hisilicon.com>
>
> arm64 depends on the cpufreq driver to gain the maximum cpu frequency
> to convert the watchdog_thresh to perf event period. cpufreq drivers
> like cppc_cpufreq will be initialized lately after the initializing of
> the hard lockup detector so just use a safe cpufreq which will be
> inaccurency. Use a cpufreq notifier to adjust the event's period to
> a more accurate one.
>
> Signed-off-by: Yicong Yang <yangyicong at hisilicon.com>
> ---
>  arch/arm64/kernel/watchdog_hld.c | 58 ++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)

I haven't had time to go through carefully and look for every possible
race condition. ...but at least this does attempt to get a bit safer
than v1 was. I also agree that it seems hard to believe this could
make things worse than not having this patch. Thus, I'm OK with:

Reviewed-by: Douglas Anderson <dianders at chromium.org>