Memoryless nodes: Add N_CPU node state

We need the check for a node with cpu in zone reclaim.  Zone reclaim will not
allow remote zone reclaim if a node has a cpu.

[Lee.Schermerhorn@hp.com: Move setup of N_CPU node state mask]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Tested-by:  Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Bob Picco <bob.picco@hp.com>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@skynet.ie>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 6 insertions, 4 deletions

diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index ccee962f3559..905e18f4b412 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -349,6 +349,7 @@ enum node_states {
 #else
         N_HIGH_MEMORY = N_NORMAL_MEMORY,
 #endif
+        N_CPU,          /* The node has one or more cpus */
         NR_NODE_STATES
 };
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 07dfd89992fa..161bcb711b30 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2353,6 +2353,9 @@ static struct per_cpu_pageset boot_pageset[NR_CPUS];
 static int __cpuinit process_zones(int cpu)
 {
         struct zone *zone, *dzone;
+        int node = cpu_to_node(cpu);
+
+        node_set_state(node, N_CPU);    /* this node has a cpu */
 
         for_each_zone(zone) {
 
@@ -2360,7 +2363,7 @@ static int __cpuinit process_zones(int cpu)
                         continue;
 
                 zone_pcp(zone, cpu) = kmalloc_node(sizeof(struct per_cpu_pageset),
-                                         GFP_KERNEL, cpu_to_node(cpu));
+                                         GFP_KERNEL, node);
                 if (!zone_pcp(zone, cpu))
                         goto bad;
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 876568847b71..8fd8ba1c67b4 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1853,7 +1853,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 
 int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 {
-        cpumask_t mask;
         int node_id;
 
         /*
@@ -1890,8 +1889,7 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
          * as wide as possible.
          */
         node_id = zone_to_nid(zone);
-        mask = node_to_cpumask(node_id);
-        if (!cpus_empty(mask) && node_id != numa_node_id())
+        if (node_state(node_id, N_CPU) && node_id != numa_node_id())
                 return 0;
         return __zone_reclaim(zone, gfp_mask, order);
 }