Re: [PATCH] i386 spinlocks should use the full 32 bits, not only 8 bits

[Arjan van de Ven <arjan@infradead.org>]

On Mon, 2005-10-17 at 00:03 -0700, Andrew Morton wrote:
> Eric Dumazet <dada1@cosmosbay.com> wrote:
> >
> >  2) The unlock sequence is not anymore inlined. It appears twice or three times 
> >  in the kernel.
> 
> Is that intentional though?  With <randon .config> my mm/swapfile.i has an
> unreferenced
> 
> static inline void __raw_spin_unlock(raw_spinlock_t *lock)
> {
> 	__asm__ __volatile__(
> 		"movb $1,%0" :"=m" (lock->slock) : : "memory" 
> 	);
> }
> 
> which either a) shouldn't be there or b) should be referenced.
> 
> Ingo, can you confirm that x86's spin_unlock is never inlined?  If so,
> what's my __raw_spin_unlock() doing there?

I would really want this one inlined! 
A movb is a much shorter code sequence than a call (esp if you factor in
argument setup). De-inlining to save space is nice and all, but it can
go too far....