Messages in this thread | | | Date | Fri, 21 May 2004 12:08:16 -0700 | From | "Martin J. Bligh" <> | Subject | Re: How can I optimize a process on a NUMA architecture(x86-64 specifically)? |
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>> Without these two things the kernel will >> just allocate on the currently running CPU whatever that may be when in >> fact a preference must be given to a CPU at some point, hopefully early >> on in the life of the process, in order to take advantage of NUMA. > > The kernel does a pretty good job of keeping processes on the CPU they've been > running on, and thus they'll probably stay close to their memory. But > without explicit pinning, there's no guarantee.
One thing I *do* want to do, is instead of explicit homenodes, is to take into account the per-node RSS of processes when doing my migration decisions. That gives us a kind of dynamic homenode. I have the per-node RSS code in my tree already from someone (Matt?), but we haven't used it. Of course, this throws off the O(1)-ness of balancing decisions, but as long as we cap the number we look at, and only do it for cross-node rebalance migrates (we don't need it for exec), I really don't care ;-)
M.
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