[PATCH v3 15/31] arm64: SMP support

[Timur Tabi]

Catalin,

I know this patch is three years old, but I have a question about it:

On Fri, Sep 7, 2012 at 9:26 AM, Catalin Marinas <catalin.marinas at arm.com> wrote:
> +static void ipi_cpu_stop(unsigned int cpu)
> +{
> +       if (system_state == SYSTEM_BOOTING ||
> +           system_state == SYSTEM_RUNNING) {
> +               raw_spin_lock(&stop_lock);
> +               pr_crit("CPU%u: stopping\n", cpu);
> +               dump_stack();
> +               raw_spin_unlock(&stop_lock);
> +       }
> +
> +       set_cpu_online(cpu, false);
> +
> +       local_fiq_disable();
> +       local_irq_disable();
> +
> +       while (1)
> +               cpu_relax();
> +}

Why do you display a message and dump the stack when a CPU is stopped?
 I ask because emergency_restart() calls this function, and so
whenever I want to do an "emergency" reboot, it dumps the stack for
each core.  On an ARM64 system with lots of cores, this produces a ton
of output.  That makes emergency_restart() almost useless.

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