| Subject | Re: [RFC][PATCH 00/26] sched/numa | From | Peter Zijlstra <> | Date | Mon, 19 Mar 2012 12:30:55 +0100 |
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On Mon, 2012-03-19 at 12:12 +0100, Peter Zijlstra wrote: > Also, if you go scan memory, you need some storage -- see how aa grows > struct page, sure he wants to move that storage some place else, but the > memory overhead is still there -- this means less memory to actually do > useful stuff in (it also probably means more cache-misses since his > proposed shadow array in pgdat is someplace else).
Going by the sizes in aa's patch, that's 96M of my 16G box gone. That puts HPC people in a rather awkward position of having to choose between more memory and slightly smarter kernel. I'm thinking they're going to opt for going the way they are now (hard affinity/userspace balancers) and use the extra memory.
This even though typical MPI implementations use the multi-process scheme, so the simple home-node approach I used works just fine for them.
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