Messages in this thread | | | Date | Tue, 1 Dec 2009 17:01:19 +0100 | From | Ingo Molnar <> | Subject | Re: problems in linux-next (Was: Re: linux-next: Tree for December 1) |
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* Christoph Lameter <cl@linux-foundation.org> wrote:
> On Tue, 1 Dec 2009, Tejun Heo wrote: > > > The problem is that on UP configurations. Percpu memory allocator > > becomes a simple wrapper around kmalloc and there's no way to > > specify larger alignment when requesting memory from kmalloc. > > There is usually no point in aligning in UP. Alignment is typically > done for smp configurations to limit cache line bouncing and control > cache line use/
There is a natural minimum alignment for UP and it's smaller than the cache-line size: machine word size. All our allocators (except bootmem) align to machine word so there's no need to specify this explicitly.
Larger alignment than that just wastes memory - which waste UP systems can afford the least.
Ingo
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