1 files changed, 21 insertions, 158 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dcc8a1cf55b6..6b23df1be909 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4858,52 +4858,18 @@ static int build_zonelists_node(pg_data_t *pgdat, struct zonelist *zonelist,
         return nr_zones;
 }
 
-
-/*
- *  zonelist_order:
- *  0 = automatic detection of better ordering.
- *  1 = order by ([node] distance, -zonetype)
- *  2 = order by (-zonetype, [node] distance)
- *
- *  If not NUMA, ZONELIST_ORDER_ZONE and ZONELIST_ORDER_NODE will create
- *  the same zonelist. So only NUMA can configure this param.
- */
-#define ZONELIST_ORDER_DEFAULT  0
-#define ZONELIST_ORDER_NODE     1
-#define ZONELIST_ORDER_ZONE     2
-
-/* zonelist order in the kernel.
- * set_zonelist_order() will set this to NODE or ZONE.
- */
-static int current_zonelist_order = ZONELIST_ORDER_DEFAULT;
-static char zonelist_order_name[3][8] = {"Default", "Node", "Zone"};
-
-
 #ifdef CONFIG_NUMA
-/* The value user specified ....changed by config */
-static int user_zonelist_order = ZONELIST_ORDER_DEFAULT;
-/* string for sysctl */
-#define NUMA_ZONELIST_ORDER_LEN 16
-char numa_zonelist_order[16] = "default";
-
-/*
- * interface for configure zonelist ordering.
- * command line option "numa_zonelist_order"
- *      = "[dD]efault   - default, automatic configuration.
- *      = "[nN]ode      - order by node locality, then by zone within node
- *      = "[zZ]one      - order by zone, then by locality within zone
- */
 
 static int __parse_numa_zonelist_order(char *s)
 {
-        if (*s == 'd' || *s == 'D') {
-                user_zonelist_order = ZONELIST_ORDER_DEFAULT;
-        } else if (*s == 'n' || *s == 'N') {
-                user_zonelist_order = ZONELIST_ORDER_NODE;
-        } else if (*s == 'z' || *s == 'Z') {
-                user_zonelist_order = ZONELIST_ORDER_ZONE;
-        } else {
-                pr_warn("Ignoring invalid numa_zonelist_order value:  %s\n", s);
+        /*
+         * We used to support different zonlists modes but they turned
+         * out to be just not useful. Let's keep the warning in place
+         * if somebody still use the cmd line parameter so that we do
+         * not fail it silently
+         */
+        if (!(*s == 'd' || *s == 'D' || *s == 'n' || *s == 'N')) {
+                pr_warn("Ignoring unsupported numa_zonelist_order value:  %s\n", s);
                 return -EINVAL;
         }
         return 0;
@@ -4911,19 +4877,15 @@ static int __parse_numa_zonelist_order(char *s)
 
 static __init int setup_numa_zonelist_order(char *s)
 {
-        int ret;
-
         if (!s)
                 return 0;
 
-        ret = __parse_numa_zonelist_order(s);
-        if (ret == 0)
-                strlcpy(numa_zonelist_order, s, NUMA_ZONELIST_ORDER_LEN);
-
-        return ret;
+        return __parse_numa_zonelist_order(s);
 }
 early_param("numa_zonelist_order", setup_numa_zonelist_order);
 
+char numa_zonelist_order[] = "Node";
+
 /*
  * sysctl handler for numa_zonelist_order
  */
@@ -4931,42 +4893,17 @@ int numa_zonelist_order_handler(struct ctl_table *table, int write,
                 void __user *buffer, size_t *length,
                 loff_t *ppos)
 {
-        char saved_string[NUMA_ZONELIST_ORDER_LEN];
+        char *str;
         int ret;
-        static DEFINE_MUTEX(zl_order_mutex);
 
-        mutex_lock(&zl_order_mutex);
-        if (write) {
-                if (strlen((char *)table->data) >= NUMA_ZONELIST_ORDER_LEN) {
-                        ret = -EINVAL;
-                        goto out;
-                }
-                strcpy(saved_string, (char *)table->data);
-        }
-        ret = proc_dostring(table, write, buffer, length, ppos);
-        if (ret)
-                goto out;
-        if (write) {
-                int oldval = user_zonelist_order;
+        if (!write)
+                return proc_dostring(table, write, buffer, length, ppos);
+        str = memdup_user_nul(buffer, 16);
+        if (IS_ERR(str))
+                return PTR_ERR(str);
 
-                ret = __parse_numa_zonelist_order((char *)table->data);
-                if (ret) {
-                        /*
-                         * bogus value.  restore saved string
-                         */
-                        strncpy((char *)table->data, saved_string,
-                                NUMA_ZONELIST_ORDER_LEN);
-                        user_zonelist_order = oldval;
-                } else if (oldval != user_zonelist_order) {
-                        mem_hotplug_begin();
-                        mutex_lock(&zonelists_mutex);
-                        build_all_zonelists(NULL, NULL);
-                        mutex_unlock(&zonelists_mutex);
-                        mem_hotplug_done();
-                }
-        }
-out:
-        mutex_unlock(&zl_order_mutex);
+        ret = __parse_numa_zonelist_order(str);
+        kfree(str);
         return ret;
 }
 
@@ -5075,70 +5012,12 @@ static void build_thisnode_zonelists(pg_data_t *pgdat)
  */
 static int node_order[MAX_NUMNODES];
 
-static void build_zonelists_in_zone_order(pg_data_t *pgdat, int nr_nodes)
-{
-        int pos, j, node;
-        int zone_type;          /* needs to be signed */
-        struct zone *z;
-        struct zonelist *zonelist;
-
-        zonelist = &pgdat->node_zonelists[ZONELIST_FALLBACK];
-        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 (managed_zone(z)) {
-                                zoneref_set_zone(z,
-                                        &zonelist->_zonerefs[pos++]);
-                                check_highest_zone(zone_type);
-                        }
-                }
-        }
-        zonelist->_zonerefs[pos].zone = NULL;
-        zonelist->_zonerefs[pos].zone_idx = 0;
-}
-
-#if defined(CONFIG_64BIT)
-/*
- * Devices that require DMA32/DMA are relatively rare and do not justify a
- * penalty to every machine in case the specialised case applies. Default
- * to Node-ordering on 64-bit NUMA machines
- */
-static int default_zonelist_order(void)
-{
-        return ZONELIST_ORDER_NODE;
-}
-#else
-/*
- * On 32-bit, the Normal zone needs to be preserved for allocations accessible
- * by the kernel. If processes running on node 0 deplete the low memory zone
- * then reclaim will occur more frequency increasing stalls and potentially
- * be easier to OOM if a large percentage of the zone is under writeback or
- * dirty. The problem is significantly worse if CONFIG_HIGHPTE is not set.
- * Hence, default to zone ordering on 32-bit.
- */
-static int default_zonelist_order(void)
-{
-        return ZONELIST_ORDER_ZONE;
-}
-#endif /* CONFIG_64BIT */
-
-static void set_zonelist_order(void)
-{
-        if (user_zonelist_order == ZONELIST_ORDER_DEFAULT)
-                current_zonelist_order = default_zonelist_order();
-        else
-                current_zonelist_order = user_zonelist_order;
-}
-
 static void build_zonelists(pg_data_t *pgdat)
 {
         int i, node, load;
         nodemask_t used_mask;
         int local_node, prev_node;
         struct zonelist *zonelist;
-        unsigned int order = current_zonelist_order;
 
         /* initialize zonelists */
         for (i = 0; i < MAX_ZONELISTS; i++) {
@@ -5168,15 +5047,7 @@ static void build_zonelists(pg_data_t *pgdat)
 
                 prev_node = node;
                 load--;
-                if (order == ZONELIST_ORDER_NODE)
-                        build_zonelists_in_node_order(pgdat, node);
-                else
-                        node_order[i++] = node; /* remember order */
-        }
-
-        if (order == ZONELIST_ORDER_ZONE) {
-                /* calculate node order -- i.e., DMA last! */
-                build_zonelists_in_zone_order(pgdat, i);
+                build_zonelists_in_node_order(pgdat, node);
         }
 
         build_thisnode_zonelists(pgdat);
@@ -5204,11 +5075,6 @@ static void setup_min_unmapped_ratio(void);
 static void setup_min_slab_ratio(void);
 #else   /* CONFIG_NUMA */
 
-static void set_zonelist_order(void)
-{
-        current_zonelist_order = ZONELIST_ORDER_ZONE;
-}
-
 static void build_zonelists(pg_data_t *pgdat)
 {
         int node, local_node;
@@ -5348,8 +5214,6 @@ build_all_zonelists_init(void)
  */
 void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
 {
-        set_zonelist_order();
-
         if (system_state == SYSTEM_BOOTING) {
                 build_all_zonelists_init();
         } else {
@@ -5375,9 +5239,8 @@ void __ref build_all_zonelists(pg_data_t *pgdat, struct zone *zone)
         else
                 page_group_by_mobility_disabled = 0;
 
-        pr_info("Built %i zonelists in %s order, mobility grouping %s.  Total pages: %ld\n",
+        pr_info("Built %i zonelists, mobility grouping %s.  Total pages: %ld\n",
                 nr_online_nodes,
-                zonelist_order_name[current_zonelist_order],
                 page_group_by_mobility_disabled ? "off" : "on",
                 vm_total_pages);
 #ifdef CONFIG_NUMA