Commit d3eb1570 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Linus Torvalds
Browse files

mempolicy: fix is_valid_nodemask()

is_valid_nodemask() was introduced by commit 19770b32 ("mm: filter
based on a nodemask as well as a gfp_mask").  but it does not match its
comments, because it does not check the zone which > policy_zone.

Also in commit b377fd39

 ("Apply memory policies to top two highest
zones when highest zone is ZONE_MOVABLE"), this commits told us, if
highest zone is ZONE_MOVABLE, we should also apply memory policies to
it.  so ZONE_MOVABLE should be valid zone for policies.
is_valid_nodemask() need to be changed to match it.

Fix: check all zones, even its zoneid > policy_zone.  Use
nodes_intersects() instead open code to check it.
Reported-by: default avatarWen Congyang <>
Signed-off-by: default avatarLai Jiangshan <>
Signed-off-by: default avatarTang Chen <>
Cc: Mel Gorman <>
Cc: Lee Schermerhorn <>
Cc: Jiang Liu <>
Cc: Jianguo Wu <>
Cc: Kamezawa Hiroyuki <>
Cc: Lai Jiangshan <>
Cc: Yasuaki Ishimatsu <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent 8a356ce3
......@@ -161,19 +161,7 @@ static const struct mempolicy_operations {
/* Check that the nodemask contains at least one populated zone */
static int is_valid_nodemask(const nodemask_t *nodemask)
int nd, k;
for_each_node_mask(nd, *nodemask) {
struct zone *z;
for (k = 0; k <= policy_zone; k++) {
z = &NODE_DATA(nd)->node_zones[k];
if (z->present_pages > 0)
return 1;
return 0;
return nodes_intersects(*nodemask, node_states[N_MEMORY]);
static inline int mpol_store_user_nodemask(const struct mempolicy *pol)
......@@ -1644,6 +1632,26 @@ struct mempolicy *get_vma_policy(struct task_struct *task,
return pol;
static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
enum zone_type dynamic_policy_zone = policy_zone;
BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
* if policy->v.nodes has movable memory only,
* we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
* policy->v.nodes is intersect with node_states[N_MEMORY].
* so if the following test faile, it implies
* policy->v.nodes has movable memory only.
if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
dynamic_policy_zone = ZONE_MOVABLE;
return zone >= dynamic_policy_zone;
* Return a nodemask representing a mempolicy for filtering nodes for
* page allocation
......@@ -1652,7 +1660,7 @@ static nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
/* Lower zones don't get a nodemask applied for MPOL_BIND */
if (unlikely(policy->mode == MPOL_BIND) &&
gfp_zone(gfp) >= policy_zone &&
apply_policy_zone(policy, gfp_zone(gfp)) &&
return &policy->v.nodes;
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment