Convert cpu_sibling_map to be a per cpu variable

Convert cpu_sibling_map from a static array sized by NR_CPUS to a per_cpu
variable.  This saves sizeof(cpumask_t) * NR unused cpus.  Access is mostly
from startup and CPU HOTPLUG functions.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 9 deletions

diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index c73b7a48b036..407d74a8a542 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -52,14 +52,13 @@ int sparc64_multi_core __read_mostly;
 
 cpumask_t cpu_possible_map __read_mostly = CPU_MASK_NONE;
 cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
-cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly =
-        { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
+DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
 cpumask_t cpu_core_map[NR_CPUS] __read_mostly =
         { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
 
 EXPORT_SYMBOL(cpu_possible_map);
 EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(cpu_sibling_map);
+EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
 EXPORT_SYMBOL(cpu_core_map);
 
 static cpumask_t smp_commenced_mask;
@@ -1261,16 +1260,16 @@ void __devinit smp_fill_in_sib_core_maps(void)
         for_each_present_cpu(i) {
                 unsigned int j;
 
-                cpus_clear(cpu_sibling_map[i]);
+                cpus_clear(per_cpu(cpu_sibling_map, i));
                 if (cpu_data(i).proc_id == -1) {
-                        cpu_set(i, cpu_sibling_map[i]);
+                        cpu_set(i, per_cpu(cpu_sibling_map, i));
                         continue;
                 }
 
                 for_each_present_cpu(j) {
                         if (cpu_data(i).proc_id ==
                             cpu_data(j).proc_id)
-                                cpu_set(j, cpu_sibling_map[i]);
+                                cpu_set(j, per_cpu(cpu_sibling_map, i));
                 }
         }
 }
@@ -1342,9 +1341,9 @@ int __cpu_disable(void)
                 cpu_clear(cpu, cpu_core_map[i]);
         cpus_clear(cpu_core_map[cpu]);
 
-        for_each_cpu_mask(i, cpu_sibling_map[cpu])
-                cpu_clear(cpu, cpu_sibling_map[i]);
-        cpus_clear(cpu_sibling_map[cpu]);
+        for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu))
+                cpu_clear(cpu, per_cpu(cpu_sibling_map, i));
+        cpus_clear(per_cpu(cpu_sibling_map, cpu));
 
         c = &cpu_data(cpu);