On Sat, Oct 10, 2020 at 10:34:04AM +0100, Marc Zyngier wrote: > On Sat, 10 Oct 2020 02:58:55 +0100, > Masayoshi Mizuma <msys.miz...@gmail.com> wrote: > > [...] > > > > +void ipi_nmi_setup(int cpu) > > > +{ > > > + if (!ipi_desc) > > > + return; > > > > ipi_nmi_setup() may be called twice for CPU0: > > > > set_smp_ipi_range => set_smp_ipi_nmi => ipi_nmi_setup > > => ipi_setup => ipi_nmi_setup > > > > Actually, I got the following error message via the second ipi_nmi_setup(): > > > > GICv3: Pseudo-NMIs enabled using relaxed ICC_PMR_EL1 synchronisation > > GICv3: Cannot set NMI property of enabled IRQ 8 > > genirq: Failed to setup NMI delivery: irq 8 > > > > Why don't we have a check to prevent that? Like as: > > > > if (cpumask_test_cpu(cpu, ipi_desc->percpu_enabled)) > > return; > > That's definitely the wrong thing to do. prepare_nmi_setup() shouldn't > be called twice, and papering over it isn't acceptable.
Got it. How about moving ipi_nmi_setup() from ipi_setup() to secondary_start_kernel() ? so that CPU0 can call ipi_nmi_setup() only from set_smp_ipi_nmi(). --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -245,6 +245,7 @@ asmlinkage notrace void secondary_start_kernel(void) notify_cpu_starting(cpu); ipi_setup(cpu); + ipi_nmi_setup(cpu); store_cpu_topology(cpu); numa_add_cpu(cpu); @@ -966,8 +967,6 @@ static void ipi_setup(int cpu) for (i = 0; i < nr_ipi; i++) enable_percpu_irq(ipi_irq_base + i, 0); - - ipi_nmi_setup(cpu); } #ifdef CONFIG_HOTPLUG_CPU Thanks, Masa _______________________________________________ Kgdb-bugreport mailing list Kgdb-bugreport@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport