Re: [rfc][patch 2/3] slab: introduce SMP alignment

[Nick Piggin]

On Mon, Mar 03, 2008 at 12:17:20PM -0800, Christoph Lameter wrote:
> On Mon, 3 Mar 2008, Nick Piggin wrote:
> 
> > > You want two ways of specifying alignments?
> > 
> > I want a way to ask for SMP friendly allocation.
> 
> Then align the objects at cacheline boundaries by providing a value for 
> the align parameter to kmem_cache_create().

max(num_possible_cpus() > 1 ? cache_line_size() : 0, mandatory_alignment)?

Then suppose we want a CONFIG_TINY option to eliminate it?

max(!CONFIG_TINY && num_possible_cpus() > 1 ? cache_line_size() : 0, mandatory_alignment)

And maybe the VSMP guys will want to blow this out to their internode
alignment?

max(!CONFIG_TINY && num_possible_cpus() > 1 ? (is_vsmp ? internode_alignemnt : cache_line_size()) : 0, mandatory_alignment)


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