Re: [PATCH] WorkStruct: Implement generic UP cmpxchg() where an arch doesn't support it

Linus Torvalds
2006-12-07T01:19:27Z

On Thu, 7 Dec 2006, Roman Zippel wrote:
> >
> > Any _real_ CPU will simply never care about _anything_ else than just the
> > size of the datum in question.
>
> ..or alignment which a dedicated atomic type would allow to be attached.

Can you give any example of a real CPU where alignment matters?

Sure, it needs to be naturally aligned, but that's true of _any_ type in
the kernel. We don't do unaligneds without "get_unaligned()" and friends.

Btw, if you want to leave out 8-bit and 16-bit data, that's fine. So
generally you'd only need to handle 32-bit (and 64-bit on a 64-bit
architecture) accesses anyway.

Linus