Re: [PATCH v2 x86 1/2] fix page faults by nmiaction in nmi if kmemcheck is enabled

Peter Zijlstra
2012-03-05T17:49:50Z

On Mon, 2012-03-05 at 18:05 +0800, Li Zhong wrote:
> +static struct nmiaction arch_trigger_all_cpu_bt_nmiaction = {
> + .handler = arch_trigger_all_cpu_backtrace_handler,
> + .name = "arch_bt",
> +};
> +
> static int __init register_trigger_all_cpu_backtrace(void)
> {
> - register_nmi_handler(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler,
> - 0, "arch_bt");
> + register_nmi_handler(NMI_LOCAL, &arch_trigger_all_cpu_bt_nmiaction);
> return 0;
> }

If you look at things like cpu_notifier() you can shorten this still:

#define nmi_notifier(t, fn, n) \
do { \
static struct nmiaction fn##_na = { \
.handler = (fn), \
.name = (n), \
}; \
register_nmi_handler((t), &fn##_na); \
} while (0)

The whole thing then becomes:

nmi_notifier(NMI_LOCAL, arch_trigger_all_cpu_backtrace_handler, "arch_bt");