On Tue, Apr 20, 2010 at 1:47 AM, Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx> wrote: > On Sat, 17 Apr 2010, Bob Liu wrote: > >> > GFP_THISNODE forces allocation from the node. Without it we will fallback. >> > >> >> Yeah, but I think we shouldn't fallback at this case, what we want is >> alloc a page >> from exactly the dest node during migrate_to_node(dest).So I added >> GFP_THISNODE. > > Why would we want that? > Because if dest node have no memory, it will fallback to other nodes. The dest node's fallback nodes may be nodes in nodemask from_nodes. It maybe make circulation ?.(I am not sure.) What's more,i think it against the user's request. The user wants to move pages from from_nodes to to_nodes, if fallback happened, the pages may be moved to other nodes instead of any node in nodemask to_nodes. I am not sure if the user can expect this and accept. Thanks a lot for your patient reply. :) -- Regards, --Bob -- 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>