Messages in this thread | | | Date | Fri, 30 May 2008 07:38:33 -0700 | From | Mike Travis <> | Subject | Re: [patch 00/41] cpu alloc / cpu ops v3: Optimize per cpu access |
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Christoph Lameter wrote: > On Thu, 29 May 2008, Andrew Morton wrote: ... >> Plus who knows what lies ahead of us? > > Well invariably we will end up with cpu area defragmentation.... Sigh. > >> I don't think there is presently any upper limit on alloc_percpu()? It >> uses kmalloc() and kmalloc_node()? >> >> Even if there is some limit, is it an unfixable one? > > No there is no limit. It just wastes lots of space (pointer arrays, > alignment etc) that we could use to configure sufficiently large per cpu > areas.
Is there any reason why the per_cpu area couldn't be made extensible? Maybe a simple linked list of available areas? (And use a config variable and/or boot param for initial size and increment size?) [Ignoring the problem of reclaiming the space...]
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