Re: [tip:core/debug] debug lockups: Improve lockup detection

Ingo Molnar
2009-08-02T20:47:03Z

* Andrew Morton <akpm@linux-foundation.org> wrote:

> #ifndef trigger_all_cpu_backtrace
> +#ifdef CONFIG_SMP
> +#warning This architecture is missing a trigger_all_cpu_backtrace() implementation
> +#endif
> #define trigger_all_cpu_backtrace() do { } while (0)
> #endif

I think a better solution will be to make this function return 1 if
it generated a backtrace.

That way we can fall back to the generic schedule_work based
codepath.

Albeit the best and cleanest solution would be to implement a
workqueue based trigger_all_cpu_backtrace() __weak variant and throw
away the workqueue bits from sysrq.c.

Ingo