[linux-next][regression] [PATCH] percpu: add preemption checks to __this_cpu ops

Christoph Lameter
2014-03-20T14:06:34Z

On Tue, 18 Mar 2014, Andrew Morton wrote:

> > snprintf can cause hangs.
>
> This is weird. How the heck can snprintf() fail if called too early?
> All it does is shuffle chars around in memory. The only external
> dependency I'm seeing is a WARN_ON() which presumably didn't trigger
> anyway.
>
> I'm suspecting a misdiagnosis here. Otherwise, we seriously need to
> fix snprintf(), not work around it!
>
> Also, what does "before checking error conditions" refer to? Does this
> mean you know why snprintf() failed??

No I dont. I only know that this fixes Grygorii's issues. There could be
numerous arch specific per cpu setup issues going on that may impact on
snprintf.

If I move it behind the checks then I can avoid using snprintf.