Hi, On Wed, Jun 3, 2026 at 7:36 AM Kiryl Shutsemau <[email protected]> wrote: > > From: "Kiryl Shutsemau (Meta)" <[email protected]> > > Select HAVE_HARDLOCKUP_DETECTOR_ARCH so the framework takes its backend > from this driver. A per-CPU hrtimer checks its buddy's heartbeat and > signals event 0 at a stalled CPU, which runs watchdog_hardlockup_check() > NMI-like. > > The source is chosen at boot: SDEI if firmware provides it, otherwise a > perf-NMI counter (pseudo-NMI) fallback -- one image covers both. > > Signed-off-by: Kiryl Shutsemau (Meta) <[email protected]> > --- > arch/arm64/Kconfig | 1 + > drivers/firmware/Kconfig | 3 + > drivers/firmware/sdei_nmi.c | 247 +++++++++++++++++++++++++++++++++++- > 3 files changed, 248 insertions(+), 3 deletions(-)
I'm a little confused about this patch. We already have a buddy hardlockup detector using the hrtimer, and it's even been improved recently to trigger in a smaller time bound. It looks as if you're duplicating bits of the perf and buddy detector here? I don't think you need this patch at all. The existing buddy detector + patches #1 and #2 in your series should be sufficient. Did I misunderstand? -Doug
