Re: Reduce struct page by 8 bytes on 64bit

[Andrew Morton]

Matthew Wilcox <[e-mail]> wrote:
>
> Jacob's would break if we hashed to different spinlocks.  But we don't, we
> shift right by 8, so we get the same spinlock for atomic things that are on
> the same "cacheline" (i think PA cachelines are actually 64 or 128 bytes,
> depending on model).
> 

Are you prepared to cast this in stone?

If so then I think Jacob's approach would be preferable, don't you agree?

It needs some compiler-detection magic around the anon union though.