diff options
| -rw-r--r-- | mm/mempolicy.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a388888b6fcf..d3c5de47ff6d 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1005,6 +1005,26 @@ int do_migrate_pages(struct mm_struct *mm, int dest = 0; for_each_node_mask(s, tmp) { + + /* + * do_migrate_pages() tries to maintain the relative + * node relationship of the pages established between + * threads and memory areas. + * + * However if the number of source nodes is not equal to + * the number of destination nodes we can not preserve + * this node relative relationship. In that case, skip + * copying memory from a node that is in the destination + * mask. + * + * Example: [2,3,4] -> [3,4,5] moves everything. + * [0-7] - > [3,4,5] moves only 0,1,2,6,7. + */ + + if ((nodes_weight(*from_nodes) != nodes_weight(*to_nodes)) && + (node_isset(s, *to_nodes))) + continue; + d = node_remap(s, *from_nodes, *to_nodes); if (s == d) continue; |