On Thu, 10 Apr 2014, Randy Dunlap wrote: > On 04/01/2014 08:53 PM, Tang Chen wrote: > > In document numa_memory_policy.txt, the following examples for flag > > MPOL_F_RELATIVE_NODES are incorrect. > > > > For example, consider a task that is attached to a cpuset with > > mems 2-5 that sets an Interleave policy over the same set with > > MPOL_F_RELATIVE_NODES. If the cpuset's mems change to 3-7, the > > interleave now occurs over nodes 3,5-6. If the cpuset's mems > > then change to 0,2-3,5, then the interleave occurs over nodes > > 0,3,5. > > > > According to the comment of the patch adding flag MPOL_F_RELATIVE_NODES, > > the nodemasks the user specifies should be considered relative to the > > current task's mems_allowed. > > (https://lkml.org/lkml/2008/2/29/428) > > > > And according to numa_memory_policy.txt, if the user's nodemask includes > > nodes that are outside the range of the new set of allowed nodes, then > > the remap wraps around to the beginning of the nodemask and, if not already > > set, sets the node in the mempolicy nodemask. > > > > So in the example, if the user specifies 2-5, for a task whose mems_allowed > > is 3-7, the nodemasks should be remapped the third, fourth, fifth, sixth > > node in mems_allowed. like the following: > > > > mems_allowed: 3 4 5 6 7 > > > > relative index: 0 1 2 3 4 > > 5 > > > > So the nodemasks should be remapped to 3,5-7, but not 3,5-6. > > > > And for a task whose mems_allowed is 0,2-3,5, the nodemasks should be > > remapped to 0,2-3,5, but not 0,3,5. > > > > mems_allowed: 0 2 3 5 > > > > relative index: 0 1 2 3 > > 4 5 > > > > > > Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx> > > Wow. This was not an April fools joke, right? > It would have been a horrible joke if it was intended to be :) > Have there been any acks of this? I haven't seen any responses to it. > Because everybody in the phonebook was cc'd on it except for the author who wrote it. Tang, good catch. Acked-by: David Rientjes <rientjes@xxxxxxxxxx> -- 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>