Re: [External] Re: [PATCH 1/2] watchdog: refactor watchdog_hld functionality

[yunhui cui <cuiyunhui@bytedance.com>]

Hi Doug，

On Wed, Sep 3, 2025 at 1:04 AM Doug Anderson <dianders@chromium.org> wrote:
>
> Hi,
>
> On Sun, Aug 31, 2025 at 10:57 PM yunhui cui <cuiyunhui@bytedance.com> wrote:
> >
> > Hi Doug,
> >
> > On Sat, Aug 30, 2025 at 5:34 AM Doug Anderson <dianders@chromium.org> wrote:
> > >
> > > Hi,
> > >
> > > On Wed, Aug 27, 2025 at 3:10 AM Yunhui Cui <cuiyunhui@bytedance.com> wrote:
> > > >
> > > > Move watchdog_hld.c to kernel/, and rename arm_pmu_irq_is_nmi()
> > > > to arch_pmu_irq_is_nmi() for cross-arch reusability.
> > > >
> > > > Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com>
> > > > ---
> > > >  arch/arm64/kernel/Makefile                   | 1 -
> > > >  drivers/perf/arm_pmu.c                       | 2 +-
> > > >  include/linux/nmi.h                          | 1 +
> > > >  include/linux/perf/arm_pmu.h                 | 2 --
> > > >  kernel/Makefile                              | 2 +-
> > > >  {arch/arm64/kernel => kernel}/watchdog_hld.c | 8 ++++++--
> > > >  6 files changed, 9 insertions(+), 7 deletions(-)
> > > >  rename {arch/arm64/kernel => kernel}/watchdog_hld.c (97%)
> > >
> > > I'm not a huge fan of the perf hardlockup detector and IMO we should
> > > maybe just delete it. Thus spreading it to support a new architecture
> > > isn't my favorite thing to do. Can't you use the buddy hardlockup
> > > detector?
> >
> > Why is there a plan to remove CONFIG_HARDLOCKUP_DETECTOR_PERF? Could
> > you explain the specific reasons? Is the community's future plan to
> > favor CONFIG_HARDLOCKUP_DETECTOR_BUDDY?
>
> I don't think there are any concrete plans, but there was some discussion here:
>
> https://lore.kernel.org/all/CAD=FV=WWUiCi6bZCs_gseFpDDWNkuJMoL6XCftEo6W7q6jRCkg@mail.gmail.com/
>
> -Doug
>

I’ve read your linked content, which details the pros and cons of perf
watchdog and buddy watchdog.
I think everyone will agree on choosing one as the default.
It seems there’s no kernel/watchdog entry in MAINTAINERS—what’s next
for these two approaches?

Thanks,
Yunhui