On Thu, 2010-09-23 at 15:29 -0700, Jeremy Cole wrote: > 1. Is it plausible that Linux for whatever reason needs memory to be > in Node 0, and chooses to page out used memory to make room, rather > than choosing to drop some of the cache in Node 1 and use that memory? > I think this is true, but maybe I've missed something important. Your situation sounds pretty familiar. It happens a lot when applications are moved over to a NUMA system for the first time. Your interleaving solution is a decent one, although teaching the database about NUMA is a much better long-term approach. As far as the decisions about running reclaim or swapping versus going to another node for an allocation, take a look at the "zone_reclaim_mode" bits in Documentation/sysctl/vm.txt . It does a decent job of explaining what we do. Most users new to NUMA systems just prefer to "echo 0 > zone_reclaim_mode". I've also run into a fair number of "tuning" guides that say to do this. It will make the allocator act a lot more like if NUMA wasn't there. It isn't as _optimized_ for NUMA locality then, but it does tend to let you allocate memory more freely. -- Dave -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>