Re: [PATCH] mm-slab: allocate kmem_cache with __GFP_REPEAT

Christoph Lameter
2011-07-20T13:56:31Z

On Wed, 20 Jul 2011, Mel Gorman wrote:

> > The changelog isn't that convincing, really. This is
> > kmem_cache_create() so I'm surprised we'd ever get NULL here in
> > practice. Does this fix some problem you're seeing? If this is
> > really an issue, I'd blame the page allocator as GFP_KERNEL should
> > just work.
> >
>
> Besides, is allocating from cache_cache really a
> PAGE_ALLOC_COSTLY_ORDER allocation? On my laptop at least, it's an
> order-2 allocation which is supporting up to 512 CPUs and 512 nodes.

Slab's kmem_cache is configured with an array of NR_CPUS which is the
maximum nr of cpus supported. Some distros support 4096 cpus in order to
accomodate SGI machines. That array then will have the size of 4096 * 8 =
32k