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authorMel Gorman <mel@csn.ul.ie>2008-04-28 02:12:18 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-28 08:58:19 -0700
commit19770b32609b6bf97a3dece2529089494cbfc549 (patch)
tree3b5922d1b20aabdf929bde9309f323841717747a /mm/mempolicy.c
parentdd1a239f6f2d4d3eedd318583ec319aa145b324c (diff)
mm: filter based on a nodemask as well as a gfp_mask
The MPOL_BIND policy creates a zonelist that is used for allocations controlled by that mempolicy. As the per-node zonelist is already being filtered based on a zone id, this patch adds a version of __alloc_pages() that takes a nodemask for further filtering. This eliminates the need for MPOL_BIND to create a custom zonelist. A positive benefit of this is that allocations using MPOL_BIND now use the local node's distance-ordered zonelist instead of a custom node-id-ordered zonelist. I.e., pages will be allocated from the closest allowed node with available memory. [Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments] [Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask] [Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c184
1 files changed, 73 insertions, 111 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 90193a2a915b..acb5ee3587c3 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -163,42 +163,25 @@ static int mpol_check_policy(int mode, nodemask_t *nodes)
return 0;
}
-/* Generate a custom zonelist for the BIND policy. */
-static struct zonelist *bind_zonelist(nodemask_t *nodes)
+/* Check that the nodemask contains at least one populated zone */
+static int is_valid_nodemask(nodemask_t *nodemask)
{
- struct zonelist *zl;
- int num, max, nd;
- enum zone_type k;
+ int nd, k;
- max = 1 + MAX_NR_ZONES * nodes_weight(*nodes);
- max++; /* space for zlcache_ptr (see mmzone.h) */
- zl = kmalloc(sizeof(struct zone *) * max, GFP_KERNEL);
- if (!zl)
- return ERR_PTR(-ENOMEM);
- zl->zlcache_ptr = NULL;
- num = 0;
- /* First put in the highest zones from all nodes, then all the next
- lower zones etc. Avoid empty zones because the memory allocator
- doesn't like them. If you implement node hot removal you
- have to fix that. */
- k = MAX_NR_ZONES - 1;
- while (1) {
- for_each_node_mask(nd, *nodes) {
- struct zone *z = &NODE_DATA(nd)->node_zones[k];
- if (z->present_pages > 0)
- zoneref_set_zone(z, &zl->_zonerefs[num++]);
+ /* Check that there is something useful in this mask */
+ k = policy_zone;
+
+ 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;
}
- if (k == 0)
- break;
- k--;
- }
- if (num == 0) {
- kfree(zl);
- return ERR_PTR(-EINVAL);
}
- zl->_zonerefs[num].zone = NULL;
- zl->_zonerefs[num].zone_idx = 0;
- return zl;
+
+ return 0;
}
/* Create a new policy */
@@ -229,12 +212,11 @@ static struct mempolicy *mpol_new(int mode, nodemask_t *nodes)
policy->v.preferred_node = -1;
break;
case MPOL_BIND:
- policy->v.zonelist = bind_zonelist(nodes);
- if (IS_ERR(policy->v.zonelist)) {
- void *error_code = policy->v.zonelist;
+ if (!is_valid_nodemask(nodes)) {
kmem_cache_free(policy_cache, policy);
- return error_code;
+ return ERR_PTR(-EINVAL);
}
+ policy->v.nodes = *nodes;
break;
}
policy->policy = mode;
@@ -500,19 +482,12 @@ static long do_set_mempolicy(int mode, nodemask_t *nodes)
/* Fill a zone bitmap for a policy */
static void get_zonemask(struct mempolicy *p, nodemask_t *nodes)
{
- int i;
-
nodes_clear(*nodes);
switch (p->policy) {
- case MPOL_BIND:
- for (i = 0; p->v.zonelist->_zonerefs[i].zone; i++) {
- struct zoneref *zref;
- zref = &p->v.zonelist->_zonerefs[i];
- node_set(zonelist_node_idx(zref), *nodes);
- }
- break;
case MPOL_DEFAULT:
break;
+ case MPOL_BIND:
+ /* Fall through */
case MPOL_INTERLEAVE:
*nodes = p->v.nodes;
break;
@@ -1160,6 +1135,18 @@ static struct mempolicy * get_vma_policy(struct task_struct *task,
return pol;
}
+/* Return a nodemask representing a mempolicy */
+static nodemask_t *nodemask_policy(gfp_t gfp, struct mempolicy *policy)
+{
+ /* Lower zones don't get a nodemask applied for MPOL_BIND */
+ if (unlikely(policy->policy == MPOL_BIND) &&
+ gfp_zone(gfp) >= policy_zone &&
+ cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
+ return &policy->v.nodes;
+
+ return NULL;
+}
+
/* Return a zonelist representing a mempolicy */
static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
{
@@ -1172,12 +1159,17 @@ static struct zonelist *zonelist_policy(gfp_t gfp, struct mempolicy *policy)
nd = numa_node_id();
break;
case MPOL_BIND:
- /* Lower zones don't get a policy applied */
- /* Careful: current->mems_allowed might have moved */
- if (gfp_zone(gfp) >= policy_zone)
- if (cpuset_zonelist_valid_mems_allowed(policy->v.zonelist))
- return policy->v.zonelist;
- /*FALL THROUGH*/
+ /*
+ * Normally, MPOL_BIND allocations node-local are node-local
+ * within the allowed nodemask. However, if __GFP_THISNODE is
+ * set and the current node is part of the mask, we use the
+ * the zonelist for the first node in the mask instead.
+ */
+ nd = numa_node_id();
+ if (unlikely(gfp & __GFP_THISNODE) &&
+ unlikely(!node_isset(nd, policy->v.nodes)))
+ nd = first_node(policy->v.nodes);
+ break;
case MPOL_INTERLEAVE: /* should not happen */
case MPOL_DEFAULT:
nd = numa_node_id();
@@ -1220,7 +1212,14 @@ unsigned slab_node(struct mempolicy *policy)
* Follow bind policy behavior and start allocation at the
* first node.
*/
- return zonelist_node_idx(policy->v.zonelist->_zonerefs);
+ struct zonelist *zonelist;
+ struct zone *zone;
+ enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
+ zonelist = &NODE_DATA(numa_node_id())->node_zonelists[0];
+ (void)first_zones_zonelist(zonelist, highest_zoneidx,
+ &policy->v.nodes,
+ &zone);
+ return zone->node;
}
case MPOL_PREFERRED:
@@ -1278,25 +1277,31 @@ static inline unsigned interleave_nid(struct mempolicy *pol,
* @vma = virtual memory area whose policy is sought
* @addr = address in @vma for shared policy lookup and interleave policy
* @gfp_flags = for requested zone
- * @mpol = pointer to mempolicy pointer for reference counted 'BIND policy
+ * @mpol = pointer to mempolicy pointer for reference counted mempolicy
+ * @nodemask = pointer to nodemask pointer for MPOL_BIND nodemask
*
* Returns a zonelist suitable for a huge page allocation.
- * If the effective policy is 'BIND, returns pointer to policy's zonelist.
+ * If the effective policy is 'BIND, returns pointer to local node's zonelist,
+ * and a pointer to the mempolicy's @nodemask for filtering the zonelist.
* If it is also a policy for which get_vma_policy() returns an extra
- * reference, we must hold that reference until after allocation.
+ * reference, we must hold that reference until after the allocation.
* In that case, return policy via @mpol so hugetlb allocation can drop
- * the reference. For non-'BIND referenced policies, we can/do drop the
+ * the reference. For non-'BIND referenced policies, we can/do drop the
* reference here, so the caller doesn't need to know about the special case
* for default and current task policy.
*/
struct zonelist *huge_zonelist(struct vm_area_struct *vma, unsigned long addr,
- gfp_t gfp_flags, struct mempolicy **mpol)
+ gfp_t gfp_flags, struct mempolicy **mpol,
+ nodemask_t **nodemask)
{
struct mempolicy *pol = get_vma_policy(current, vma, addr);
struct zonelist *zl;
*mpol = NULL; /* probably no unref needed */
- if (pol->policy == MPOL_INTERLEAVE) {
+ *nodemask = NULL; /* assume !MPOL_BIND */
+ if (pol->policy == MPOL_BIND) {
+ *nodemask = &pol->v.nodes;
+ } else if (pol->policy == MPOL_INTERLEAVE) {
unsigned nid;
nid = interleave_nid(pol, vma, addr, HPAGE_SHIFT);
@@ -1376,14 +1381,15 @@ alloc_page_vma(gfp_t gfp, struct vm_area_struct *vma, unsigned long addr)
/*
* slow path: ref counted policy -- shared or vma
*/
- struct page *page = __alloc_pages(gfp, 0, zl);
+ struct page *page = __alloc_pages_nodemask(gfp, 0,
+ zl, nodemask_policy(gfp, pol));
__mpol_free(pol);
return page;
}
/*
* fast path: default or task policy
*/
- return __alloc_pages(gfp, 0, zl);
+ return __alloc_pages_nodemask(gfp, 0, zl, nodemask_policy(gfp, pol));
}
/**
@@ -1415,7 +1421,8 @@ struct page *alloc_pages_current(gfp_t gfp, unsigned order)
pol = &default_policy;
if (pol->policy == MPOL_INTERLEAVE)
return alloc_page_interleave(gfp, order, interleave_nodes(pol));
- return __alloc_pages(gfp, order, zonelist_policy(gfp, pol));
+ return __alloc_pages_nodemask(gfp, order,
+ zonelist_policy(gfp, pol), nodemask_policy(gfp, pol));
}
EXPORT_SYMBOL(alloc_pages_current);
@@ -1440,14 +1447,6 @@ struct mempolicy *__mpol_copy(struct mempolicy *old)
}
*new = *old;
atomic_set(&new->refcnt, 1);
- if (new->policy == MPOL_BIND) {
- int sz = ksize(old->v.zonelist);
- new->v.zonelist = kmemdup(old->v.zonelist, sz, GFP_KERNEL);
- if (!new->v.zonelist) {
- kmem_cache_free(policy_cache, new);
- return ERR_PTR(-ENOMEM);
- }
- }
return new;
}
@@ -1461,21 +1460,12 @@ int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
switch (a->policy) {
case MPOL_DEFAULT:
return 1;
+ case MPOL_BIND:
+ /* Fall through */
case MPOL_INTERLEAVE:
return nodes_equal(a->v.nodes, b->v.nodes);
case MPOL_PREFERRED:
return a->v.preferred_node == b->v.preferred_node;
- case MPOL_BIND: {
- int i;
- for (i = 0; a->v.zonelist->_zonerefs[i].zone; i++) {
- struct zone *za, *zb;
- za = zonelist_zone(&a->v.zonelist->_zonerefs[i]);
- zb = zonelist_zone(&b->v.zonelist->_zonerefs[i]);
- if (za != zb)
- return 0;
- }
- return b->v.zonelist->_zonerefs[i].zone == NULL;
- }
default:
BUG();
return 0;
@@ -1487,8 +1477,6 @@ void __mpol_free(struct mempolicy *p)
{
if (!atomic_dec_and_test(&p->refcnt))
return;
- if (p->policy == MPOL_BIND)
- kfree(p->v.zonelist);
p->policy = MPOL_DEFAULT;
kmem_cache_free(policy_cache, p);
}
@@ -1779,6 +1767,8 @@ static void mpol_rebind_policy(struct mempolicy *pol,
switch (pol->policy) {
case MPOL_DEFAULT:
break;
+ case MPOL_BIND:
+ /* Fall through */
case MPOL_INTERLEAVE:
nodes_remap(tmp, pol->v.nodes, *mpolmask, *newmask);
pol->v.nodes = tmp;
@@ -1791,32 +1781,6 @@ static void mpol_rebind_policy(struct mempolicy *pol,
*mpolmask, *newmask);
*mpolmask = *newmask;
break;
- case MPOL_BIND: {
- nodemask_t nodes;
- struct zoneref *z;
- struct zonelist *zonelist;
-
- nodes_clear(nodes);
- for (z = pol->v.zonelist->_zonerefs; z->zone; z++)
- node_set(zonelist_node_idx(z), nodes);
- nodes_remap(tmp, nodes, *mpolmask, *newmask);
- nodes = tmp;
-
- zonelist = bind_zonelist(&nodes);
-
- /* If no mem, then zonelist is NULL and we keep old zonelist.
- * If that old zonelist has no remaining mems_allowed nodes,
- * then zonelist_policy() will "FALL THROUGH" to MPOL_DEFAULT.
- */
-
- if (!IS_ERR(zonelist)) {
- /* Good - got mem - substitute new zonelist */
- kfree(pol->v.zonelist);
- pol->v.zonelist = zonelist;
- }
- *mpolmask = *newmask;
- break;
- }
default:
BUG();
break;
@@ -1879,9 +1843,7 @@ static inline int mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
break;
case MPOL_BIND:
- get_zonemask(pol, &nodes);
- break;
-
+ /* Fall through */
case MPOL_INTERLEAVE:
nodes = pol->v.nodes;
break;