Re: [PATCH] fs: fcntl_setlease defies lease_init assumptions

From: Linus Torvalds
Date: Tue May 09 2006 - 10:40:41 EST




On Mon, 8 May 2006, Christoph Lameter wrote:
>
> On Mon, 8 May 2006, Pekka Enberg wrote:
>
> > > I think it sounds like it's worth it, but I'm not going to really push it.
> >
> > Sounds good to me. Andrew?
>
> virt_to_page is not cheap on NUMA.

Right now the __cache_free() chain does "virt_to_page()" on NUMA
regardless, through the

#ifdef CONFIG_NUMA
{
struct slab *slabp;
slabp = virt_to_slab(objp);
,,,

thing. The suggested patch obviously makes it do it _twice_: once to get
the cachep, once to get the slabp. But some simple re-organization would
make it do it just once, if we passed in the "struct page *" instead of
the "struct cachep" - since in the end, every single path into the real
core of the allocator does end up needing it.

Linus
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