cpumask: convert node_to_cpumask_map[] to cpumask_var_t

Impact: reduce kernel memory usage when CONFIG_CPUMASK_OFFSTACK=y

Straightforward conversion: done for 32 and 64 bit kernels.
node_to_cpumask_map is now a cpumask_var_t array.

64-bit used to be a dynamic cpumask_t array, and 32-bit used to be a
static cpumask_t array.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 12 insertions, 16 deletions

diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index f3a19e939e80..429dc2d191fd 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -12,7 +12,7 @@
 /*
  * Which logical CPUs are on which nodes
  */
-cpumask_t *node_to_cpumask_map;
+cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
 EXPORT_SYMBOL(node_to_cpumask_map);
 
 /*
@@ -25,7 +25,6 @@ EXPORT_SYMBOL(node_to_cpumask_map);
 void __init setup_node_to_cpumask_map(void)
 {
 	unsigned int node, num = 0;
-	cpumask_t *map;
 
 	/* setup nr_node_ids if not done yet */
 	if (nr_node_ids == MAX_NUMNODES) {
@@ -35,14 +34,11 @@ void __init setup_node_to_cpumask_map(void)
 	}
 
 	/* allocate the map */
-	map = alloc_bootmem_low(nr_node_ids * sizeof(cpumask_t));
-	DBG("node_to_cpumask_map at %p for %d nodes\n", map, nr_node_ids);
+	for (node = 0; node < nr_node_ids; node++)
+		alloc_bootmem_cpumask_var(&node_to_cpumask_map[node]);
 
-	pr_debug("Node to cpumask map at %p for %d nodes\n",
-		 map, nr_node_ids);
-
-	/* node_to_cpumask() will now work */
-	node_to_cpumask_map = map;
+	/* cpumask_of_node() will now work */
+	pr_debug("Node to cpumask map for %d nodes\n", nr_node_ids);
 }
 
 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
@@ -51,13 +47,6 @@ void __init setup_node_to_cpumask_map(void)
  */
 const cpumask_t *cpumask_of_node(int node)
 {
-	if (node_to_cpumask_map == NULL) {
-		printk(KERN_WARNING
-			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
-			node);
-		dump_stack();
-		return cpu_online_mask;
-	}
 	if (node >= nr_node_ids) {
 		printk(KERN_WARNING
 			"cpumask_of_node(%d): node > nr_node_ids(%d)\n",
@@ -65,6 +54,13 @@ const cpumask_t *cpumask_of_node(int node)
 		dump_stack();
 		return cpu_none_mask;
 	}
+	if (node_to_cpumask_map[node] == NULL) {
+		printk(KERN_WARNING
+			"cpumask_of_node(%d): no node_to_cpumask_map!\n",
+			node);
+		dump_stack();
+		return cpu_online_mask;
+	}
 	return &node_to_cpumask_map[node];
 }
 EXPORT_SYMBOL(cpumask_of_node);