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, 4 insertions, 2 deletions

diff --git a/include/asm-x86/smp_64.h b/include/asm-x86/smp_64.h
index 65f844864415..f5bcee1c0927 100644
--- a/include/asm-x86/smp_64.h
+++ b/include/asm-x86/smp_64.h
@@ -38,12 +38,14 @@ extern void unlock_ipi_call_lock(void);
 extern int smp_num_siblings;
 extern void smp_send_reschedule(int cpu);
 
-extern cpumask_t cpu_sibling_map[NR_CPUS];
 /*
- * cpu_core_map lives in a per cpu area
+ * cpu_sibling_map and cpu_core_map now live
+ * in the per cpu area
  *
+ * extern cpumask_t cpu_sibling_map[NR_CPUS];
  * extern cpumask_t cpu_core_map[NR_CPUS];
  */
+DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
 DECLARE_PER_CPU(cpumask_t, cpu_core_map);
 extern u8 cpu_llc_id[NR_CPUS];