x86: Convert cpu_core_map to be a per cpu variable

This is from an earlier message from 'Christoph Lameter':

    cpu_core_map is currently an array defined using NR_CPUS. This means that
    we overallocate since we will rarely really use maximum configured cpu.

    If we put the cpu_core_map into the per cpu area then it will be allocated
    for each processor as it comes online.

    This means that the core map cannot be accessed until the per cpu area
    has been allocated. Xen does a weird thing here looping over all processors
    and zeroing the masks that are not yet allocated and that will be zeroed
    when they are allocated. I commented the code out.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 12 deletions

diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c
index 720a7d1f886..6723c862282 100644
--- a/arch/x86/kernel/smpboot_64.c
+++ b/arch/x86/kernel/smpboot_64.c
@@ -95,8 +95,8 @@ cpumask_t cpu_sibling_map[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(cpu_sibling_map);
 
 /* representing HT and core siblings of each logical CPU */
-cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
-EXPORT_SYMBOL(cpu_core_map);
+DEFINE_PER_CPU(cpumask_t, cpu_core_map);
+EXPORT_PER_CPU_SYMBOL(cpu_core_map);
 
 /*
  * Trampoline 80x86 program as an array.
@@ -243,7 +243,7 @@ cpumask_t cpu_coregroup_map(int cpu)
 	 * And for power savings, we return cpu_core_map
 	 */
 	if (sched_mc_power_savings || sched_smt_power_savings)
-		return cpu_core_map[cpu];
+		return per_cpu(cpu_core_map, cpu);
 	else
 		return c->llc_shared_map;
 }
@@ -264,8 +264,8 @@ static inline void set_cpu_sibling_map(int cpu)
 			    c[cpu].cpu_core_id == c[i].cpu_core_id) {
 				cpu_set(i, cpu_sibling_map[cpu]);
 				cpu_set(cpu, cpu_sibling_map[i]);
-				cpu_set(i, cpu_core_map[cpu]);
-				cpu_set(cpu, cpu_core_map[i]);
+				cpu_set(i, per_cpu(cpu_core_map, cpu));
+				cpu_set(cpu, per_cpu(cpu_core_map, i));
 				cpu_set(i, c[cpu].llc_shared_map);
 				cpu_set(cpu, c[i].llc_shared_map);
 			}
@@ -277,7 +277,7 @@ static inline void set_cpu_sibling_map(int cpu)
 	cpu_set(cpu, c[cpu].llc_shared_map);
 
 	if (current_cpu_data.x86_max_cores == 1) {
-		cpu_core_map[cpu] = cpu_sibling_map[cpu];
+		per_cpu(cpu_core_map, cpu) = cpu_sibling_map[cpu];
 		c[cpu].booted_cores = 1;
 		return;
 	}
@@ -289,8 +289,8 @@ static inline void set_cpu_sibling_map(int cpu)
 			cpu_set(cpu, c[i].llc_shared_map);
 		}
 		if (c[cpu].phys_proc_id == c[i].phys_proc_id) {
-			cpu_set(i, cpu_core_map[cpu]);
-			cpu_set(cpu, cpu_core_map[i]);
+			cpu_set(i, per_cpu(cpu_core_map, cpu));
+			cpu_set(cpu, per_cpu(cpu_core_map, i));
 			/*
 			 *  Does this new cpu bringup a new core?
 			 */
@@ -736,7 +736,7 @@ static __init void disable_smp(void)
 	else
 		phys_cpu_present_map = physid_mask_of_physid(0);
 	cpu_set(0, cpu_sibling_map[0]);
-	cpu_set(0, cpu_core_map[0]);
+	cpu_set(0, per_cpu(cpu_core_map, 0));
 }
 
 #ifdef CONFIG_HOTPLUG_CPU
@@ -971,8 +971,8 @@ static void remove_siblinginfo(int cpu)
 	int sibling;
 	struct cpuinfo_x86 *c = cpu_data;
 
-	for_each_cpu_mask(sibling, cpu_core_map[cpu]) {
-		cpu_clear(cpu, cpu_core_map[sibling]);
+	for_each_cpu_mask(sibling, per_cpu(cpu_core_map, cpu)) {
+		cpu_clear(cpu, per_cpu(cpu_core_map, sibling));
 		/*
 		 * last thread sibling in this cpu core going down
 		 */
@@ -983,7 +983,7 @@ static void remove_siblinginfo(int cpu)
 	for_each_cpu_mask(sibling, cpu_sibling_map[cpu])
 		cpu_clear(cpu, cpu_sibling_map[sibling]);
 	cpus_clear(cpu_sibling_map[cpu]);
-	cpus_clear(cpu_core_map[cpu]);
+	cpus_clear(per_cpu(cpu_core_map, cpu));
 	c[cpu].phys_proc_id = 0;
 	c[cpu].cpu_core_id = 0;
 	cpu_clear(cpu, cpu_sibling_setup_map);