Re: [rfc][patch 1/3] slub: fix small HWCACHE_ALIGN alignment

Pekka Enberg
2008-03-03T21:37:19Z

Hi,

Christoph Lameter wrote:
> Well the guarantee can only be exploited if you would check the cacheline
> sizes and the object size from the code that creates the slab cache.
> Basically you would have to guestimate what the slab allocator is doing.
>
> So the guarantee is basically meaningless. If the object is larger than a
> cacheline then this will never work.

Yes, I know that. That's why I am asking why this matters. If there's
some sort of regression because SLUB does HWCACHE_ALIGN bit differently,
we need to fix that. Not that it necessarily means we have to change
HWCACHE_ALIGN but I am assuming Nick has some reason why he wants to
introduce the SMP alignment flag.

Pekka