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

From: Pekka Enberg
Date: Mon Mar 03 2008 - 16:31:26 EST


Hi,

On Mon, 3 Mar 2008, Nick Piggin wrote:
> > > HWCACHE_ALIGN means that you want the object to be aligned at
> > > cacheline boundaries for optimization. Why does crossing cacheline
> > > boundaries matter in this case?
> >
> > No, HWCACHE_ALIGN means that you want the object not to cross cacheline
> > boundaries for at least cache_line_size() bytes. You invented new

On Mon, Mar 3, 2008 at 11:16 PM, Christoph Lameter <clameter@xxxxxxx> wrote:
> Interesting new definition....

Well, not my definition either but SLAB has guaranteed that for small
objects in the past, so I think Nick has a point here. However, with
all this back and forth, I've lost track why this matters. I suppose
it causes regression on some workload?

Pekka
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