On Wed, Apr 28, 2010 at 03:40:34PM -0700, Andrew Morton wrote: > On Wed, 28 Apr 2010 10:04:32 -0500 > Jack Steiner <steiner@xxxxxxx> wrote: > > > Some workloads that create a large number of small files tend to assign > > too many pages to node 0 (multi-node systems). Part of the reason is that > > the rotor (in cpuset_mem_spread_node()) used to assign nodes starts > > at node 0 for newly created tasks. > > And, presumably, your secret testcase forks lots of subprocesses which > do the file creation? I think the test case he was using was aim7 or a kernel compile. Anything that opens a lot of small files will quickly deplete node 0. > > This patch changes the rotor to be initialized to a random node number > > of the cpuset. > > Why random as opposed to, say, inherit-rotor-from-parent? If I have something like a find ... -exec grep ..., won't the pages be biased towards the nodes adjacent to the parent's rotor values. Maybe I misunderstood Jack's problem, but I believe that was what he was seeing and why he chose random. I hope I did not misunderstand Jack's problem and mislead this discussion. Thanks, Robin Holt -- 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>