[PATCH] x86_64: CPU hotplug sibling map cleanup

This patch is a minor cleanup to the cpu sibling/core map.  It is required
that this setup happens on a per-cpu bringup time.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/x86_64/kernel/smpboot.c b/arch/x86_64/kernel/smpboot.c
index 5a3f955..571a554 100644 (file)
--- a/arch/x86_64/kernel/smpboot.c
+++ b/arch/x86_64/kernel/smpboot.c
@@ -445,6 +445,33 @@ void __cpuinit smp_callin(void)
        cpu_set(cpuid, cpu_callin_map);
 }
 
+static inline void set_cpu_sibling_map(int cpu)
+{
+       int i;
+
+       if (smp_num_siblings > 1) {
+               for_each_cpu(i) {
+                       if (cpu_core_id[cpu] == cpu_core_id[i]) {
+                               cpu_set(i, cpu_sibling_map[cpu]);
+                               cpu_set(cpu, cpu_sibling_map[i]);
+                       }
+               }
+       } else {
+               cpu_set(cpu, cpu_sibling_map[cpu]);
+       }
+
+       if (current_cpu_data.x86_num_cores > 1) {
+               for_each_cpu(i) {
+                       if (phys_proc_id[cpu] == phys_proc_id[i]) {
+                               cpu_set(i, cpu_core_map[cpu]);
+                               cpu_set(cpu, cpu_core_map[i]);
+                       }
+               }
+       } else {
+               cpu_core_map[cpu] = cpu_sibling_map[cpu];
+       }
+}
+
 /*
  * Setup code on secondary processor (after comming out of the trampoline)
  */
@@ -474,6 +501,12 @@ void __cpuinit start_secondary(void)
 
        enable_APIC_timer();
 
+       /*
+        * The sibling maps must be set before turing the online map on for
+        * this cpu
+        */
+       set_cpu_sibling_map(smp_processor_id());
+
        /*
         * Allow the master to continue.
         */
@@ -816,51 +849,6 @@ do_rest:
 cycles_t cacheflush_time;
 unsigned long cache_decay_ticks;
 
-/*
- * Construct cpu_sibling_map[], so that we can tell the sibling CPU
- * on SMT systems efficiently.
- */
-static __cpuinit void detect_siblings(void)
-{
-       int cpu;
-
-       for (cpu = 0; cpu < NR_CPUS; cpu++) {
-               cpus_clear(cpu_sibling_map[cpu]);
-               cpus_clear(cpu_core_map[cpu]);
-       }
-
-       for_each_online_cpu (cpu) {
-               struct cpuinfo_x86 *c = cpu_data + cpu;
-               int siblings = 0;
-               int i;
-               if (smp_num_siblings > 1) {
-                       for_each_online_cpu (i) {
-                               if (cpu_core_id[cpu] == cpu_core_id[i]) {
-                                       siblings++;
-                                       cpu_set(i, cpu_sibling_map[cpu]);
-                               }
-                       }
-               } else {
-                       siblings++;
-                       cpu_set(cpu, cpu_sibling_map[cpu]);
-               }
-
-               if (siblings != smp_num_siblings) {
-                       printk(KERN_WARNING
-              "WARNING: %d siblings found for CPU%d, should be %d\n",
-                              siblings, cpu, smp_num_siblings);
-                       smp_num_siblings = siblings;
-               }
-               if (c->x86_num_cores > 1) {
-                       for_each_online_cpu(i) {
-                               if (phys_proc_id[cpu] == phys_proc_id[i])
-                                       cpu_set(i, cpu_core_map[cpu]);
-                       }
-               } else
-                       cpu_core_map[cpu] = cpu_sibling_map[cpu];
-       }
-}
-
 /*
  * Cleanup possible dangling ends...
  */
@@ -1048,6 +1036,8 @@ void __init smp_prepare_boot_cpu(void)
        int me = smp_processor_id();
        cpu_set(me, cpu_online_map);
        cpu_set(me, cpu_callout_map);
+       cpu_set(0, cpu_sibling_map[0]);
+       cpu_set(0, cpu_core_map[0]);
 }
 
 /*
@@ -1107,7 +1097,6 @@ void __init smp_cpus_done(unsigned int max_cpus)
        setup_ioapic_dest();
 #endif
 
-       detect_siblings();
        time_init_gtod();
 
        check_nmi_watchdog();
@@ -1115,8 +1104,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 
 #ifdef CONFIG_HOTPLUG_CPU
 
-static void
-remove_siblinginfo(int cpu)
+static void remove_siblinginfo(int cpu)
 {
        int sibling;