Re: [v2 PATCH 1/3] panic: Change nmi_panic from macro to function

From: Michal Hocko
Date: Wed Mar 02 2016 - 08:19:09 EST


On Wed 02-03-16 19:36:26, Hidehiro Kawai wrote:
[...]
> +void nmi_panic(struct pt_regs *regs, const char *fmt, ...)

Do we really need vargs? All the current users seem to be OK with a
simple string. This makes the code slightly more complicated without any
apparent reason.

> +{
> + static char buf[1024]; /* protected by panic_cpu */
> + va_list args;
> + int old_cpu, cpu;
> +
> + cpu = raw_smp_processor_id();
> + old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
> +
> + if (old_cpu == PANIC_CPU_INVALID) {
> + va_start(args, fmt);
> + vsnprintf(buf, sizeof(buf), fmt, args);
> + va_end(args);
> +
> + panic("%s", buf);
> + } else if (old_cpu != cpu)
> + nmi_panic_self_stop(regs);
> +}
> +EXPORT_SYMBOL(nmi_panic);
> +
> /**
> * panic - halt the system
> * @fmt: The text string to print
>
>

--
Michal Hocko
SUSE Labs