Messages in this thread | | | From | "Tomohiro Misono (Fujitsu)" <> | Subject | RE: [PATCH v11 5/6] arm64: smp: IPI_CPU_STOP and IPI_CPU_CRASH_STOP should try for NMI | Date | Tue, 29 Aug 2023 05:30:35 +0000 |
| |
> -----Original Message----- > There's no reason why IPI_CPU_STOP and IPI_CPU_CRASH_STOP can't be > handled as NMI. They are very simple and everything in them is > NMI-safe. Mark them as things to use NMI for if NMI is available. > > Suggested-by: Mark Rutland <mark.rutland@arm.com> > Reviewed-by: Stephen Boyd <swboyd@chromium.org> > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > I don't actually have any good way to test/validate this patch. It's > added to the series at Mark's request.
For IPI_CPU_CRASH_STOP, I briefly checked that HARDLOCKUP-ed CPU (by lkdtm) received the ipi upon crash dump request when pseudo NMI is enabled. Reviewed-by: Misono Tomohiro <misono.tomohiro@fujitsu.com>
Regards, Tomohiro
> > (no changes since v10) > > Changes in v10: > - ("IPI_CPU_STOP and IPI_CPU_CRASH_STOP should try for NMI") new for > v10. > > arch/arm64/kernel/smp.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c > index c8896cbc5327..4566934aaf9f 100644 > --- a/arch/arm64/kernel/smp.c > +++ b/arch/arm64/kernel/smp.c > @@ -946,6 +946,8 @@ static bool ipi_should_be_nmi(enum ipi_msg_type ipi) > return false; > > switch (ipi) { > + case IPI_CPU_STOP: > + case IPI_CPU_CRASH_STOP: > case IPI_CPU_BACKTRACE: > return true; > default: > -- > 2.42.0.rc1.204.g551eb34607-goog > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
| |