mempolicy: fix is_valid_nodemask() (d3eb1570) · Commits · 戴 / test

is_valid_nodemask() was introduced by commit ("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 ("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:

Wen Congyang <wency@cn.fujitsu.com> Signed-off-by:

Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by:

Tang Chen <tangchen@cn.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Jianguo Wu <wujianguo@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/mempolicy.c

+22 −14

Original line number	Diff line number	Diff line
		@@ -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)) &&
		cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
		return &policy->v.nodes;

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