Re: [PATCH] kexec jump: fix compiling warning on xchg(&kexec_lock, 0) in kernel_kexec()

Linus Torvalds
2008-08-13T16:58:47Z

On Wed, 13 Aug 2008, Huang Ying wrote:
>
> - xchg(&kexec_lock, 0);
> + locked = xchg(&kexec_lock, 0);
> + BUG_ON(!locked);

Why do you want to do this at all?

And why do you implement your locks with xchg() in the first place? That's
total and utter crap.

Hint: we have _real_ locking primitives in the kernel.

Linus