Messages in this thread | | | Date | Fri, 18 Nov 2011 09:56:15 -0600 (CST) | From | Christoph Lameter <> | Subject | Re: [RFC]numa: improve I/O performance by optimizing numa interleave allocation |
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On Fri, 18 Nov 2011, Shaohua Li wrote:
> So can we make both interleave fairness and continuous allocation happy?
Maybe.
> Simplily we can adjust the round robin algorithm. We switch to another node > after several (N) allocation happens. If N isn't too big, we can still get > fair allocation. And we get N continuous pages. I use N=8 in below patch. > I thought 8 isn't too big for modern NUMA machine. Applications which use > interleave are unlikely run short time, so I thought fairness still works.
People are already complaining that the 4k interleaving is too coarse. Bioses can often interleave on a cacheline level. A smaller size balances the load better over multiple nodes. Large sizes can result in imbalances since f.e. a whole array may end up on one node. Maybe make it tunable by expanding the numa_policy structure to include a size parameter?
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