[PATCH v5 0/2] Add HARDLOCKUP_DETECTOR_PERF support for RISC-V

[Doug Anderson]

Hi,

On Mon, Nov 10, 2025 at 11:35 PM Yunhui Cui <cuiyunhui at bytedance.com> wrote:
>
> After discussion [1],[2], hardlockup_perf cannot be completely replaced by
> the hardlockup_buddy approach, so this patch is still being submitted.
>
> v1->v2:
> The contents of arch/arm64/watchdog_hld.c are directly consolidated into
> kernel/watchdog_perf.c.
>
>
> v2->v3:
> Add CONFIG_WATCHDOG_PERF_ADJUST_PERIOD to enclose the period update logic,
> select it by default on arm64 and riscv, without affecting other arches
> like x86 and PPC.
>
> v3->v4:
> Place the line "select WATCHDOG_PERF_ADJUST_PERIOD if HARDLOCKUP_DETECTOR_PERF && CPU_FREQ"
> in the Kconfig files for arm64 and riscv in one line, with no line breaks.
>
> v4->v5:
> Remove __weak from hw_nmi_get_sample_period()
>
> Link: https://lore.kernel.org/all/CAD=FV=UEhVCD6JehQi1wor2sSmtTLDyf=37xfo-DOTK1=u1xzA@mail.gmail.com/ [1]
> Link: https://lore.kernel.org/all/20250916145122.416128-1-wangjinchao600@gmail.com/ [2]
>
> Yunhui Cui (2):
>   watchdog: move arm64 watchdog_hld into common code
>   riscv: add HARDLOCKUP_DETECTOR_PERF support
>
>  arch/arm64/Kconfig               |  1 +
>  arch/arm64/kernel/Makefile       |  1 -
>  arch/arm64/kernel/watchdog_hld.c | 94 --------------------------------
>  arch/riscv/Kconfig               |  3 +
>  drivers/perf/arm_pmu.c           | 10 +++-
>  drivers/perf/riscv_pmu_sbi.c     | 10 ++++
>  include/linux/perf/arm_pmu.h     |  2 -
>  kernel/watchdog_perf.c           | 83 ++++++++++++++++++++++++++++
>  lib/Kconfig.debug                |  8 +++
>  9 files changed, 114 insertions(+), 98 deletions(-)
>  delete mode 100644 arch/arm64/kernel/watchdog_hld.c

Perhaps you missed that (I think) Andrew had already dropped your v4
due to the Kernel Test Robot finding a problem. See:

https://lore.kernel.org/r/202510240701.eB6r97V3-lkp@intel.com

I don't think you've fixed these problems in v5, have you? I think you
need a v6 for it? I haven't dug all the way, but I'd suspect the
compile error is if "HARDLOCKUP_DETECTOR_PERF" is defined but not
"CPU_FREQ". Indeed, that matches the config in the report...


-Doug