mm: use two zonelist that are filtered by GFP mask

Currently a node has two sets of zonelists, one for each zone type in the
system and a second set for GFP_THISNODE allocations.  Based on the zones
allowed by a gfp mask, one of these zonelists is selected.  All of these
zonelists consume memory and occupy cache lines.

This patch replaces the multiple zonelists per-node with two zonelists.  The
first contains all populated zones in the system, ordered by distance, for
fallback allocations when the target/preferred node has no free pages.  The
second contains all populated zones in the node suitable for GFP_THISNODE
allocations.

An iterator macro is introduced called for_each_zone_zonelist() that interates
through each zone allowed by the GFP flags in the selected zonelist.

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: Christoph Lameter <clameter@sgi.com>
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>

10 files changed, 168 insertions, 154 deletions

diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c
index eb80f5e33d7d..9bb6136d77c2 100644
--- a/arch/parisc/mm/init.c
+++ b/arch/parisc/mm/init.c
@@ -603,15 +603,18 @@ void show_mem(void)
 #ifdef CONFIG_DISCONTIGMEM
         {
                 struct zonelist *zl;
-                int i, j, k;
+                int i, j;
 
                 for (i = 0; i < npmem_ranges; i++) {
+                        zl = node_zonelist(i);
                         for (j = 0; j < MAX_NR_ZONES; j++) {
-                                zl = NODE_DATA(i)->node_zonelists + j;
+                                struct zone **z;
+                                struct zone *zone;
 
                                 printk("Zone list for zone %d on node %d: ", j, i);
-                                for (k = 0; zl->zones[k] != NULL; k++) 
-                                        printk("[%d/%s] ", zone_to_nid(zl->zones[k]), zl->zones[k]->name);
+                                for_each_zone_zonelist(zone, z, zl, j)
+                                        printk("[%d/%s] ", zone_to_nid(zone),
+                                                                zone->name);
                                 printk("\n");
                         }
                 }
diff --git a/fs/buffer.c b/fs/buffer.c
index 71358499bc57..9b5434a80479 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -360,16 +360,18 @@ void invalidate_bdev(struct block_device *bdev)
  */
 static void free_more_memory(void)
 {
-        struct zonelist *zonelist;
+        struct zone **zones;
         int nid;
 
         wakeup_pdflush(1024);
         yield();
 
         for_each_online_node(nid) {
-                zonelist = node_zonelist(nid, GFP_NOFS);
-                if (zonelist->zones[0])
-                        try_to_free_pages(zonelist, 0, GFP_NOFS);
+                zones = first_zones_zonelist(node_zonelist(nid, GFP_NOFS),
+                                                gfp_zone(GFP_NOFS));
+                if (*zones)
+                        try_to_free_pages(node_zonelist(nid, GFP_NOFS), 0,
+                                                GFP_NOFS);
         }
 }
 
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index e865d51f1c74..e1c6064cb6c7 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -151,17 +151,26 @@ static inline enum zone_type gfp_zone(gfp_t flags)
  * virtual kernel addresses to the allocated page(s).
  */
 
+static inline int gfp_zonelist(gfp_t flags)
+{
+        if (NUMA_BUILD && unlikely(flags & __GFP_THISNODE))
+                return 1;
+
+        return 0;
+}
+
 /*
  * We get the zone list from the current node and the gfp_mask.
  * This zone list contains a maximum of MAXNODES*MAX_NR_ZONES zones.
- * There are many zonelists per node, two for each active zone.
+ * There are two zonelists per node, one for all zones with memory and
+ * one containing just zones from the node the zonelist belongs to.
  *
  * For the normal case of non-DISCONTIGMEM systems the NODE_DATA() gets
  * optimized to &contig_page_data at compile-time.
  */
 static inline struct zonelist *node_zonelist(int nid, gfp_t flags)
 {
-        return NODE_DATA(nid)->node_zonelists + gfp_zone(flags);
+        return NODE_DATA(nid)->node_zonelists + gfp_zonelist(flags);
 }
 
 #ifndef HAVE_ARCH_FREE_PAGE
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 451eaa13bc28..d5c33a0b89e9 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -393,10 +393,10 @@ static inline int zone_is_oom_locked(const struct zone *zone)
  * The NUMA zonelists are doubled becausse we need zonelists that restrict the
  * allocations to a single node for GFP_THISNODE.
  *
- * [0 .. MAX_NR_ZONES -1]               : Zonelists with fallback
- * [MAZ_NR_ZONES ... MAZ_ZONELISTS -1]  : No fallback (GFP_THISNODE)
+ * [0]  : Zonelist with fallback
+ * [1]  : No fallback (GFP_THISNODE)
  */
-#define MAX_ZONELISTS (2 * MAX_NR_ZONES)
+#define MAX_ZONELISTS 2
 
 
 /*
@@ -464,7 +464,7 @@ struct zonelist_cache {
         unsigned long last_full_zap;            /* when last zap'd (jiffies) */
 };
 #else
-#define MAX_ZONELISTS MAX_NR_ZONES
+#define MAX_ZONELISTS 1
 struct zonelist_cache;
 #endif
 
@@ -486,24 +486,6 @@ struct zonelist {
 #endif
 };
 
-#ifdef CONFIG_NUMA
-/*
- * Only custom zonelists like MPOL_BIND need to be filtered as part of
- * policies. As described in the comment for struct zonelist_cache, these
- * zonelists will not have a zlcache so zlcache_ptr will not be set. Use
- * that to determine if the zonelists needs to be filtered or not.
- */
-static inline int alloc_should_filter_zonelist(struct zonelist *zonelist)
-{
-        return !zonelist->zlcache_ptr;
-}
-#else
-static inline int alloc_should_filter_zonelist(struct zonelist *zonelist)
-{
-        return 0;
-}
-#endif /* CONFIG_NUMA */
-
 #ifdef CONFIG_ARCH_POPULATES_NODE_MAP
 struct node_active_region {
         unsigned long start_pfn;
@@ -731,6 +713,45 @@ extern struct zone *next_zone(struct zone *zone);
              zone;                                      \
              zone = next_zone(zone))
 
+/* Returns the first zone at or below highest_zoneidx in a zonelist */
+static inline struct zone **first_zones_zonelist(struct zonelist *zonelist,
+                                        enum zone_type highest_zoneidx)
+{
+        struct zone **z;
+
+        /* Find the first suitable zone to use for the allocation */
+        z = zonelist->zones;
+        while (*z && zone_idx(*z) > highest_zoneidx)
+                z++;
+
+        return z;
+}
+
+/* Returns the next zone at or below highest_zoneidx in a zonelist */
+static inline struct zone **next_zones_zonelist(struct zone **z,
+                                        enum zone_type highest_zoneidx)
+{
+        /* Find the next suitable zone to use for the allocation */
+        while (*z && zone_idx(*z) > highest_zoneidx)
+                z++;
+
+        return z;
+}
+
+/**
+ * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
+ * @zone - The current zone in the iterator
+ * @z - The current pointer within zonelist->zones being iterated
+ * @zlist - The zonelist being iterated
+ * @highidx - The zone index of the highest zone to return
+ *
+ * This iterator iterates though all zones at or below a given zone index.
+ */
+#define for_each_zone_zonelist(zone, z, zlist, highidx) \
+        for (z = first_zones_zonelist(zlist, highidx), zone = *z++;     \
+                zone;                                                   \
+                z = next_zones_zonelist(z, highidx), zone = *z++)
+
 #ifdef CONFIG_SPARSEMEM
 #include <asm/sparsemem.h>
 #endif
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 51c9e2c01640..ddd141cad77f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -97,11 +97,11 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
         struct mempolicy *mpol;
         struct zonelist *zonelist = huge_zonelist(vma, address,
                                         htlb_alloc_mask, &mpol);
-        struct zone **z;
+        struct zone *zone, **z;
 
-        for (z = zonelist->zones; *z; z++) {
-                nid = zone_to_nid(*z);
-                if (cpuset_zone_allowed_softwall(*z, htlb_alloc_mask) &&
+        for_each_zone_zonelist(zone, z, zonelist, MAX_NR_ZONES - 1) {
+                nid = zone_to_nid(zone);
+                if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
                     !list_empty(&hugepage_freelists[nid])) {
                         page = list_entry(hugepage_freelists[nid].next,
                                           struct page, lru);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index beb592fe9389..2c93502cfcb4 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -175,12 +175,14 @@ static inline enum oom_constraint constrained_alloc(struct zonelist *zonelist,
                                                     gfp_t gfp_mask)
 {
 #ifdef CONFIG_NUMA
+        struct zone *zone;
         struct zone **z;
+        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
         nodemask_t nodes = node_states[N_HIGH_MEMORY];
 
-        for (z = zonelist->zones; *z; z++)
-                if (cpuset_zone_allowed_softwall(*z, gfp_mask))
-                        node_clear(zone_to_nid(*z), nodes);
+        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx)
+                if (cpuset_zone_allowed_softwall(zone, gfp_mask))
+                        node_clear(zone_to_nid(zone), nodes);
                 else
                         return CONSTRAINT_CPUSET;
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 187efd47a446..4ccb8651cf22 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1378,42 +1378,29 @@ static void zlc_mark_zone_full(struct zonelist *zonelist, struct zone **z)
  */
 static struct page *
 get_page_from_freelist(gfp_t gfp_mask, unsigned int order,
-                struct zonelist *zonelist, int alloc_flags)
+                struct zonelist *zonelist, int high_zoneidx, int alloc_flags)
 {
         struct zone **z;
         struct page *page = NULL;
-        int classzone_idx = zone_idx(zonelist->zones[0]);
+        int classzone_idx;
         struct zone *zone, *preferred_zone;
         nodemask_t *allowednodes = NULL;/* zonelist_cache approximation */
         int zlc_active = 0;             /* set if using zonelist_cache */
         int did_zlc_setup = 0;          /* just call zlc_setup() one time */
-        enum zone_type highest_zoneidx = -1; /* Gets set for policy zonelists */
+
+        z = first_zones_zonelist(zonelist, high_zoneidx);
+        classzone_idx = zone_idx(*z);
+        preferred_zone = *z;
 
 zonelist_scan:
         /*
          * Scan zonelist, looking for a zone with enough free.
          * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
          */
-        z = zonelist->zones;
-        preferred_zone = *z;
-
-        do {
-                /*
-                 * In NUMA, this could be a policy zonelist which contains
-                 * zones that may not be allowed by the current gfp_mask.
-                 * Check the zone is allowed by the current flags
-                 */
-                if (unlikely(alloc_should_filter_zonelist(zonelist))) {
-                        if (highest_zoneidx == -1)
-                                highest_zoneidx = gfp_zone(gfp_mask);
-                        if (zone_idx(*z) > highest_zoneidx)
-                                continue;
-                }
-
+        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
                 if (NUMA_BUILD && zlc_active &&
                         !zlc_zone_worth_trying(zonelist, z, allowednodes))
                                 continue;
-                zone = *z;
                 if ((alloc_flags & ALLOC_CPUSET) &&
                         !cpuset_zone_allowed_softwall(zone, gfp_mask))
                                 goto try_next_zone;
@@ -1447,7 +1434,7 @@ try_next_zone:
                         zlc_active = 1;
                         did_zlc_setup = 1;
                 }
-        } while (*(++z) != NULL);
+        }
 
         if (unlikely(NUMA_BUILD && page == NULL && zlc_active)) {
                 /* Disable zlc cache for second zonelist scan */
@@ -1465,6 +1452,7 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order,
                 struct zonelist *zonelist)
 {
         const gfp_t wait = gfp_mask & __GFP_WAIT;
+        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
         struct zone **z;
         struct page *page;
         struct reclaim_state reclaim_state;
@@ -1490,7 +1478,7 @@ restart:
         }
 
         page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
-                                zonelist, ALLOC_WMARK_LOW|ALLOC_CPUSET);
+                        zonelist, high_zoneidx, ALLOC_WMARK_LOW|ALLOC_CPUSET);
         if (page)
                 goto got_pg;
 
@@ -1534,7 +1522,8 @@ restart:
          * Ignore cpuset if GFP_ATOMIC (!wait) rather than fail alloc.
          * See also cpuset_zone_allowed() comment in kernel/cpuset.c.
          */
-        page = get_page_from_freelist(gfp_mask, order, zonelist, alloc_flags);
+        page = get_page_from_freelist(gfp_mask, order, zonelist,
+                                                high_zoneidx, alloc_flags);
         if (page)
                 goto got_pg;
 
@@ -1547,7 +1536,7 @@ rebalance:
 nofail_alloc:
                         /* go through the zonelist yet again, ignoring mins */
                         page = get_page_from_freelist(gfp_mask, order,
-                                zonelist, ALLOC_NO_WATERMARKS);
+                                zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
                         if (page)
                                 goto got_pg;
                         if (gfp_mask & __GFP_NOFAIL) {
@@ -1582,7 +1571,7 @@ nofail_alloc:
 
         if (likely(did_some_progress)) {
                 page = get_page_from_freelist(gfp_mask, order,
-                                                zonelist, alloc_flags);
+                                        zonelist, high_zoneidx, alloc_flags);
                 if (page)
                         goto got_pg;
         } else if ((gfp_mask & __GFP_FS) && !(gfp_mask & __GFP_NORETRY)) {
@@ -1598,7 +1587,7 @@ nofail_alloc:
                  * under heavy pressure.
                  */
                 page = get_page_from_freelist(gfp_mask|__GFP_HARDWALL, order,
-                                zonelist, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
+                        zonelist, high_zoneidx, ALLOC_WMARK_HIGH|ALLOC_CPUSET);
                 if (page) {
                         clear_zonelist_oom(zonelist);
                         goto got_pg;
@@ -1713,14 +1702,15 @@ EXPORT_SYMBOL(free_pages);
 
 static unsigned int nr_free_zone_pages(int offset)
 {
+        struct zone **z;
+        struct zone *zone;
+
         /* Just pick one node, since fallback list is circular */
         unsigned int sum = 0;
 
         struct zonelist *zonelist = node_zonelist(numa_node_id(), GFP_KERNEL);
-        struct zone **zonep = zonelist->zones;
-        struct zone *zone;
 
-        for (zone = *zonep++; zone; zone = *zonep++) {
+        for_each_zone_zonelist(zone, z, zonelist, offset) {
                 unsigned long size = zone->present_pages;
                 unsigned long high = zone->pages_high;
                 if (size > high)
@@ -2078,17 +2068,15 @@ static int find_next_best_node(int node, nodemask_t *used_node_mask)
  */
 static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
 {
-        enum zone_type i;
         int j;
         struct zonelist *zonelist;
 
-        for (i = 0; i < MAX_NR_ZONES; i++) {
-                zonelist = pgdat->node_zonelists + i;
-                for (j = 0; zonelist->zones[j] != NULL; j++)
-                        ;
-                j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
-                zonelist->zones[j] = NULL;
-        }
+        zonelist = &pgdat->node_zonelists[0];
+        for (j = 0; zonelist->zones[j] != NULL; j++)
+                ;
+        j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+                                                        MAX_NR_ZONES - 1);
+        zonelist->zones[j] = NULL;
 }
 
 /*
@@ -2096,15 +2084,12 @@ static void build_zonelists_in_node_order(pg_data_t *pgdat, int node)
  */
 static void build_thisnode_zonelists(pg_data_t *pgdat)
 {
-        enum zone_type i;
         int j;
         struct zonelist *zonelist;
 
-        for (i = 0; i < MAX_NR_ZONES; i++) {
-                zonelist = pgdat->node_zonelists + MAX_NR_ZONES + i;
-                j = build_zonelists_node(pgdat, zonelist, 0, i);
-                zonelist->zones[j] = NULL;
-        }
+        zonelist = &pgdat->node_zonelists[1];
+        j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
+        zonelist->zones[j] = NULL;
 }
 
 /*
@@ -2117,27 +2102,24 @@ static int node_order[MAX_NUMNODES];
 
 static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
 {
-        enum zone_type i;
         int pos, j, node;
         int zone_type;          /* needs to be signed */
         struct zone *z;
         struct zonelist *zonelist;
 
-        for (i = 0; i < MAX_NR_ZONES; i++) {
-                zonelist = pgdat->node_zonelists + i;
-                pos = 0;
-                for (zone_type = i; zone_type >= 0; zone_type--) {
-                        for (j = 0; j < nr_nodes; j++) {
-                                node = node_order[j];
-                                z = &NODE_DATA(node)->node_zones[zone_type];
-                                if (populated_zone(z)) {
-                                        zonelist->zones[pos++] = z;
-                                        check_highest_zone(zone_type);
-                                }
+        zonelist = &pgdat->node_zonelists[0];
+        pos = 0;
+        for (zone_type = MAX_NR_ZONES - 1; zone_type >= 0; zone_type--) {
+                for (j = 0; j < nr_nodes; j++) {
+                        node = node_order[j];
+                        z = &NODE_DATA(node)->node_zones[zone_type];
+                        if (populated_zone(z)) {
+                                zonelist->zones[pos++] = z;
+                                check_highest_zone(zone_type);
                         }
                 }
-                zonelist->zones[pos] = NULL;
         }
+        zonelist->zones[pos] = NULL;
 }
 
 static int default_zonelist_order(void)
@@ -2264,19 +2246,15 @@ static void build_zonelists(pg_data_t *pgdat)
 /* Construct the zonelist performance cache - see further mmzone.h */
 static void build_zonelist_cache(pg_data_t *pgdat)
 {
-        int i;
-
-        for (i = 0; i < MAX_NR_ZONES; i++) {
-                struct zonelist *zonelist;
-                struct zonelist_cache *zlc;
-                struct zone **z;
+        struct zonelist *zonelist;
+        struct zonelist_cache *zlc;
+        struct zone **z;
 
-                zonelist = pgdat->node_zonelists + i;
-                zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
-                bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
-                for (z = zonelist->zones; *z; z++)
-                        zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z);
-        }
+        zonelist = &pgdat->node_zonelists[0];
+        zonelist->zlcache_ptr = zlc = &zonelist->zlcache;
+        bitmap_zero(zlc->fullzones, MAX_ZONES_PER_ZONELIST);
+        for (z = zonelist->zones; *z; z++)
+                zlc->z_to_n[z - zonelist->zones] = zone_to_nid(*z);
 }
 
 
@@ -2290,45 +2268,43 @@ static void set_zonelist_order(void)
 static void build_zonelists(pg_data_t *pgdat)
 {
         int node, local_node;
-        enum zone_type i,j;
+        enum zone_type j;
+        struct zonelist *zonelist;
 
         local_node = pgdat->node_id;
-        for (i = 0; i < MAX_NR_ZONES; i++) {
-                struct zonelist *zonelist;
 
-                zonelist = pgdat->node_zonelists + i;
+        zonelist = &pgdat->node_zonelists[0];
+        j = build_zonelists_node(pgdat, zonelist, 0, MAX_NR_ZONES - 1);
 
-                j = build_zonelists_node(pgdat, zonelist, 0, i);
-                /*
-                 * Now we build the zonelist so that it contains the zones
-                 * of all the other nodes.
-                 * We don't want to pressure a particular node, so when
-                 * building the zones for node N, we make sure that the
-                 * zones coming right after the local ones are those from
-                 * node N+1 (modulo N)
-                 */
-                for (node = local_node + 1; node < MAX_NUMNODES; node++) {
-                        if (!node_online(node))
-                                continue;
-                        j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
-                }
-                for (node = 0; node < local_node; node++) {
-                        if (!node_online(node))
-                                continue;
-                        j = build_zonelists_node(NODE_DATA(node), zonelist, j, i);
-                }
-
-                zonelist->zones[j] = NULL;
+        /*
+         * Now we build the zonelist so that it contains the zones
+         * of all the other nodes.
+         * We don't want to pressure a particular node, so when
+         * building the zones for node N, we make sure that the
+         * zones coming right after the local ones are those from
+         * node N+1 (modulo N)
+         */
+        for (node = local_node + 1; node < MAX_NUMNODES; node++) {
+                if (!node_online(node))
+                        continue;
+                j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+                                                        MAX_NR_ZONES - 1);
         }
+        for (node = 0; node < local_node; node++) {
+                if (!node_online(node))
+                        continue;
+                j = build_zonelists_node(NODE_DATA(node), zonelist, j,
+                                                        MAX_NR_ZONES - 1);
+        }
+
+        zonelist->zones[j] = NULL;
 }
 
 /* non-NUMA variant of zonelist performance cache - just NULL zlcache_ptr */
 static void build_zonelist_cache(pg_data_t *pgdat)
 {
-        int i;
-
-        for (i = 0; i < MAX_NR_ZONES; i++)
-                pgdat->node_zonelists[i].zlcache_ptr = NULL;
+        pgdat->node_zonelists[0].zlcache_ptr = NULL;
+        pgdat->node_zonelists[1].zlcache_ptr = NULL;
 }
 
 #endif  /* CONFIG_NUMA */
diff --git a/mm/slab.c b/mm/slab.c
index 5488c54b1172..29851841da62 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3243,6 +3243,8 @@ static void *fallback_alloc(struct kmem_cache *cache, gfp_t flags)
         struct zonelist *zonelist;
         gfp_t local_flags;
         struct zone **z;
+        struct zone *zone;
+        enum zone_type high_zoneidx = gfp_zone(flags);
         void *obj = NULL;
         int nid;
 
@@ -3257,10 +3259,10 @@ retry:
          * Look through allowed nodes for objects available
          * from existing per node queues.
          */
-        for (z = zonelist->zones; *z && !obj; z++) {
-                nid = zone_to_nid(*z);
+        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
+                nid = zone_to_nid(zone);
 
-                if (cpuset_zone_allowed_hardwall(*z, flags) &&
+                if (cpuset_zone_allowed_hardwall(zone, flags) &&
                         cache->nodelists[nid] &&
                         cache->nodelists[nid]->free_objects)
                                 obj = ____cache_alloc_node(cache,
diff --git a/mm/slub.c b/mm/slub.c
index 19ebbfb20689..80d20cc1c0f8 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1285,6 +1285,8 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
 #ifdef CONFIG_NUMA
         struct zonelist *zonelist;
         struct zone **z;
+        struct zone *zone;
+        enum zone_type high_zoneidx = gfp_zone(flags);
         struct page *page;
 
         /*
@@ -1310,12 +1312,12 @@ static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
                 return NULL;
 
         zonelist = node_zonelist(slab_node(current->mempolicy), flags);
-        for (z = zonelist->zones; *z; z++) {
+        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
                 struct kmem_cache_node *n;
 
-                n = get_node(s, zone_to_nid(*z));
+                n = get_node(s, zone_to_nid(zone));
 
-                if (n && cpuset_zone_allowed_hardwall(*z, flags) &&
+                if (n && cpuset_zone_allowed_hardwall(zone, flags) &&
                                 n->nr_partial > MIN_PARTIAL) {
                         page = get_partial_node(n);
                         if (page)
diff --git a/mm/vmscan.c b/mm/vmscan.c
index ef8551e0d2d0..0515b8f44894 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1249,15 +1249,13 @@ static unsigned long shrink_zone(int priority, struct zone *zone,
 static unsigned long shrink_zones(int priority, struct zonelist *zonelist,
                                         struct scan_control *sc)
 {
+        enum zone_type high_zoneidx = gfp_zone(sc->gfp_mask);
         unsigned long nr_reclaimed = 0;
-        struct zone **zones = zonelist->zones;
-        int i;
-
+        struct zone **z;
+        struct zone *zone;
 
         sc->all_unreclaimable = 1;
-        for (i = 0; zones[i] != NULL; i++) {
-                struct zone *zone = zones[i];
-
+        for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
                 if (!populated_zone(zone))
                         continue;
                 /*
@@ -1311,8 +1309,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
         unsigned long nr_reclaimed = 0;
         struct reclaim_state *reclaim_state = current->reclaim_state;
         unsigned long lru_pages = 0;
-        struct zone **zones = zonelist->zones;
-        int i;
+        struct zone **z;
+        struct zone *zone;
+        enum zone_type high_zoneidx = gfp_zone(gfp_mask);
 
         if (scan_global_lru(sc))
                 count_vm_event(ALLOCSTALL);
@@ -1320,8 +1319,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
          * mem_cgroup will not do shrink_slab.
          */
         if (scan_global_lru(sc)) {
-                for (i = 0; zones[i] != NULL; i++) {
-                        struct zone *zone = zones[i];
+                for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
 
                         if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
                                 continue;
@@ -1385,8 +1383,7 @@ out:
                 priority = 0;
 
         if (scan_global_lru(sc)) {
-                for (i = 0; zones[i] != NULL; i++) {
-                        struct zone *zone = zones[i];
+                for_each_zone_zonelist(zone, z, zonelist, high_zoneidx) {
 
                         if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL))
                                 continue;