x86: remove the static 256k node_to_cpumask_map

  * Consolidate node_to_cpumask operations and remove the 256k
    byte node_to_cpumask_map.  This is done by allocating the
    node_to_cpumask_map array after the number of possible nodes
    (nr_node_ids) is known.

  * Debug printouts when CONFIG_DEBUG_PER_CPU_MAPS is active have
    been increased.  It now shows faults when calling node_to_cpumask()
    and node_to_cpumask_ptr().

For inclusion into sched-devel/latest tree.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 127 insertions, 5 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 0dff17ee3d73..913af838c3c5 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -35,6 +35,16 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
 /* map cpu index to node index */
 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
+
+/* which logical CPUs are on which nodes */
+cpumask_t *node_to_cpumask_map;
+EXPORT_SYMBOL(node_to_cpumask_map);
+
+/* setup node_to_cpumask_map */
+static void __init setup_node_to_cpumask_map(void);
+
+#else
+static inline void setup_node_to_cpumask_map(void) { }
 #endif
 
 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_X86_SMP)
@@ -140,11 +150,15 @@ void __init setup_per_cpu_areas(void)
         }
 
         nr_cpu_ids = highest_cpu + 1;
-        printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d\n", NR_CPUS, nr_cpu_ids);
+        printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d, nr_node_ids %d\n",
+                NR_CPUS, nr_cpu_ids, nr_node_ids);
 
         /* Setup percpu data maps */
         setup_per_cpu_maps();
 
+        /* Setup node to cpumask map */
+        setup_node_to_cpumask_map();
+
         /* Setup cpumask_of_cpu map */
         setup_cpumask_of_cpu();
 }
@@ -152,6 +166,35 @@ void __init setup_per_cpu_areas(void)
 #endif
 
 #ifdef X86_64_NUMA
+
+/*
+ * Allocate node_to_cpumask_map based on number of available nodes
+ * Requires node_possible_map to be valid.
+ *
+ * Note: node_to_cpumask() is not valid until after this is done.
+ */
+static 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) {
+                for_each_node_mask(node, node_possible_map)
+                        num = node;
+                nr_node_ids = num + 1;
+        }
+
+        /* allocate the map */
+        map = alloc_bootmem_low(nr_node_ids * sizeof(cpumask_t));
+
+        Dprintk(KERN_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;
+}
+
 void __cpuinit numa_set_node(int cpu, int node)
 {
         int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
@@ -174,6 +217,8 @@ void __cpuinit numa_clear_node(int cpu)
         numa_set_node(cpu, NUMA_NO_NODE);
 }
 
+#ifndef CONFIG_DEBUG_PER_CPU_MAPS
+
 void __cpuinit numa_add_cpu(int cpu)
 {
         cpu_set(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
@@ -183,9 +228,44 @@ void __cpuinit numa_remove_cpu(int cpu)
 {
         cpu_clear(cpu, node_to_cpumask_map[cpu_to_node(cpu)]);
 }
-#endif /* CONFIG_NUMA */
 
-#if defined(CONFIG_DEBUG_PER_CPU_MAPS) && defined(CONFIG_X86_64)
+#else /* CONFIG_DEBUG_PER_CPU_MAPS */
+
+/*
+ * --------- debug versions of the numa functions ---------
+ */
+static void __cpuinit numa_set_cpumask(int cpu, int enable)
+{
+        int node = cpu_to_node(cpu);
+        cpumask_t *mask;
+        char buf[64];
+
+        if (node_to_cpumask_map == NULL) {
+                printk(KERN_ERR "node_to_cpumask_map NULL\n");
+                dump_stack();
+                return;
+        }
+
+        mask = &node_to_cpumask_map[node];
+        if (enable)
+                cpu_set(cpu, *mask);
+        else
+                cpu_clear(cpu, *mask);
+
+        cpulist_scnprintf(buf, sizeof(buf), *mask);
+        printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
+                enable? "numa_add_cpu":"numa_remove_cpu", cpu, node, buf);
+ }
+
+void __cpuinit numa_add_cpu(int cpu)
+{
+        numa_set_cpumask(cpu, 1);
+}
+
+void __cpuinit numa_remove_cpu(int cpu)
+{
+        numa_set_cpumask(cpu, 0);
+}
 
 int cpu_to_node(int cpu)
 {
@@ -199,6 +279,10 @@ int cpu_to_node(int cpu)
 }
 EXPORT_SYMBOL(cpu_to_node);
 
+/*
+ * Same function as cpu_to_node() but used if called before the
+ * per_cpu areas are setup.
+ */
 int early_cpu_to_node(int cpu)
 {
         if (early_per_cpu_ptr(x86_cpu_to_node_map))
@@ -207,9 +291,47 @@ int early_cpu_to_node(int cpu)
         if (!per_cpu_offset(cpu)) {
                 printk(KERN_WARNING
                         "early_cpu_to_node(%d): no per_cpu area!\n", cpu);
-                        dump_stack();
+                dump_stack();
                 return NUMA_NO_NODE;
         }
         return per_cpu(x86_cpu_to_node_map, cpu);
 }
-#endif
+
+/*
+ * Returns a pointer to the bitmask of CPUs on Node 'node'.
+ */
+cpumask_t *_node_to_cpumask_ptr(int node)
+{
+        if (node_to_cpumask_map == NULL) {
+                printk(KERN_WARNING
+                        "_node_to_cpumask_ptr(%d): no node_to_cpumask_map!\n",
+                        node);
+                dump_stack();
+                return &cpu_online_map;
+        }
+        return &node_to_cpumask_map[node];
+}
+EXPORT_SYMBOL(_node_to_cpumask_ptr);
+
+/*
+ * Returns a bitmask of CPUs on Node 'node'.
+ */
+cpumask_t node_to_cpumask(int node)
+{
+        if (node_to_cpumask_map == NULL) {
+                printk(KERN_WARNING
+                        "node_to_cpumask(%d): no node_to_cpumask_map!\n", node);
+                dump_stack();
+                return cpu_online_map;
+        }
+        return node_to_cpumask_map[node];
+}
+EXPORT_SYMBOL(node_to_cpumask);
+
+/*
+ * --------- end of debug versions of the numa functions ---------
+ */
+
+#endif /* CONFIG_DEBUG_PER_CPU_MAPS */
+
+#endif /* X86_64_NUMA */