On 10/07/2013 06:29 AM, Mel Gorman wrote: > This patch favours moving tasks towards NUMA node that recorded a higher > number of NUMA faults during active load balancing. Ideally this is > self-reinforcing as the longer the task runs on that node, the more faults > it should incur causing task_numa_placement to keep the task running on that > node. In reality a big weakness is that the nodes CPUs can be overloaded > and it would be more efficient to queue tasks on an idle node and migrate > to the new node. This would require additional smarts in the balancer so > for now the balancer will simply prefer to place the task on the preferred > node for a PTE scans which is controlled by the numa_balancing_settle_count > sysctl. Once the settle_count number of scans has complete the schedule > is free to place the task on an alternative node if the load is imbalanced. > > [srikar@xxxxxxxxxxxxxxxxxx: Fixed statistics] > [peterz@xxxxxxxxxxxxx: Tunable and use higher faults instead of preferred] > Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > Signed-off-by: Mel Gorman <mgorman@xxxxxxx> Acked-by: Rik van Riel <riel@xxxxxxxxxx> -- All rights reversed -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>