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

[Ingo Molnar]

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

> > instead? Not that that's really right either, but at least it avoids 
> > the _ridiculous_ crap. The real solution is probably to use a 
> > spinlock and trylock/unlock.
> 
> Or test_and_set_bit().  That's what I've been saying too, only 
> differently ;)
> 
> But cleaning up the long-standing silly usage of xchg() is a different 
> activity from suppressing this recently-added compile warning.

actually, in this case i disagree: the warning here is a canary that 
there's something wrong about this code - i.e. gcc is _right_ about 
warning us. The warning is also totally harmless - the warning shows us 
the suckiness of the code structure - and squashing the warning doesnt 
fix that.

So im coal-mine analogies, i disagree with squashing the canary, we 
should find and fix the shaft that emits the smelly methane instead ;-)

	Ingo