diff options
| -rw-r--r-- | mm/mempolicy.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index a8db92c236974..56f9a6ed939ad 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1874,11 +1874,17 @@ bool apply_policy_zone(struct mempolicy *policy, enum zone_type zone) static unsigned int weighted_interleave_nodes(struct mempolicy *policy) { - unsigned int node = current->il_prev; + unsigned int node; + unsigned int cpuset_mems_cookie; +retry: + /* to prevent miscount use tsk->mems_allowed_seq to detect rebind */ + cpuset_mems_cookie = read_mems_allowed_begin(); + node = current->il_prev; if (!current->il_weight || !node_isset(node, policy->nodes)) { node = next_node_in(node, policy->nodes); - /* can only happen if nodemask is being rebound */ + if (read_mems_allowed_retry(cpuset_mems_cookie)) + goto retry; if (node == MAX_NUMNODES) return node; current->il_prev = node; @@ -1892,8 +1898,14 @@ static unsigned int weighted_interleave_nodes(struct mempolicy *policy) static unsigned int interleave_nodes(struct mempolicy *policy) { unsigned int nid; + unsigned int cpuset_mems_cookie; + + /* to prevent miscount, use tsk->mems_allowed_seq to detect rebind */ + do { + cpuset_mems_cookie = read_mems_allowed_begin(); + nid = next_node_in(current->il_prev, policy->nodes); + } while (read_mems_allowed_retry(cpuset_mems_cookie)); - nid = next_node_in(current->il_prev, policy->nodes); if (nid < MAX_NUMNODES) current->il_prev = nid; return nid; @@ -2370,6 +2382,7 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, struct page **page_array) { struct task_struct *me = current; + unsigned int cpuset_mems_cookie; unsigned long total_allocated = 0; unsigned long nr_allocated = 0; unsigned long rounds; @@ -2387,7 +2400,13 @@ static unsigned long alloc_pages_bulk_array_weighted_interleave(gfp_t gfp, if (!nr_pages) return 0; - nnodes = read_once_policy_nodemask(pol, &nodes); + /* read the nodes onto the stack, retry if done during rebind */ + do { + cpuset_mems_cookie = read_mems_allowed_begin(); + nnodes = read_once_policy_nodemask(pol, &nodes); + } while (read_mems_allowed_retry(cpuset_mems_cookie)); + + /* if the nodemask has become invalid, we cannot do anything */ if (!nnodes) return 0; |