1 files changed, 33 insertions, 15 deletions

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 10ba5f1004a5..f17e9854c246 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -216,7 +216,6 @@ static int __ref take_cpu_down(void *_param)
 static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 {
         int err, nr_calls = 0;
-        struct task_struct *p;
         cpumask_t old_allowed, tmp;
         void *hcpu = (void *)(long)cpu;
         unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
@@ -249,21 +248,18 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
         cpus_setall(tmp);
         cpu_clear(cpu, tmp);
         set_cpus_allowed_ptr(current, &tmp);
+        tmp = cpumask_of_cpu(cpu);
 
-        p = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
-
-        if (IS_ERR(p) || cpu_online(cpu)) {
+        err = __stop_machine(take_cpu_down, &tcd_param, &tmp);
+        if (err) {
                 /* CPU didn't die: tell everyone.  Can't complain. */
                 if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
                                             hcpu) == NOTIFY_BAD)
                         BUG();
 
-                if (IS_ERR(p)) {
-                        err = PTR_ERR(p);
-                        goto out_allowed;
-                }
-                goto out_thread;
+                goto out_allowed;
         }
+        BUG_ON(cpu_online(cpu));
 
         /* Wait for it to sleep (leaving idle task). */
         while (!idle_cpu(cpu))
@@ -279,8 +275,6 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 
         check_for_tasks(cpu);
 
-out_thread:
-        err = kthread_stop(p);
 out_allowed:
         set_cpus_allowed_ptr(current, &old_allowed);
 out_release:
@@ -355,6 +349,8 @@ static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen)
                 goto out_notify;
         BUG_ON(!cpu_online(cpu));
 
+        cpu_set(cpu, cpu_active_map);
+
         /* Now call notifier in preparation. */
         raw_notifier_call_chain(&cpu_chain, CPU_ONLINE | mod, hcpu);
 
@@ -373,7 +369,7 @@ int __cpuinit cpu_up(unsigned int cpu)
         if (!cpu_isset(cpu, cpu_possible_map)) {
                 printk(KERN_ERR "can't online cpu %d because it is not "
                         "configured as may-hotadd at boot time\n", cpu);
-#if defined(CONFIG_IA64) || defined(CONFIG_X86_64) || defined(CONFIG_S390)
+#if defined(CONFIG_IA64) || defined(CONFIG_X86_64)
                 printk(KERN_ERR "please check additional_cpus= boot "
                                 "parameter\n");
 #endif
@@ -389,9 +385,6 @@ int __cpuinit cpu_up(unsigned int cpu)
 
         err = _cpu_up(cpu, 0);
 
-        if (cpu_online(cpu))
-                cpu_set(cpu, cpu_active_map);
-
 out:
         cpu_maps_update_done();
         return err;
@@ -461,3 +454,28 @@ out:
 #endif /* CONFIG_PM_SLEEP_SMP */
 
 #endif /* CONFIG_SMP */
+
+/*
+ * cpu_bit_bitmap[] is a special, "compressed" data structure that
+ * represents all NR_CPUS bits binary values of 1<<nr.
+ *
+ * It is used by cpumask_of_cpu() to get a constant address to a CPU
+ * mask value that has a single bit set only.
+ */
+
+/* cpu_bit_bitmap[0] is empty - so we can back into it */
+#define MASK_DECLARE_1(x)       [x+1][0] = 1UL << (x)
+#define MASK_DECLARE_2(x)       MASK_DECLARE_1(x), MASK_DECLARE_1(x+1)
+#define MASK_DECLARE_4(x)       MASK_DECLARE_2(x), MASK_DECLARE_2(x+2)
+#define MASK_DECLARE_8(x)       MASK_DECLARE_4(x), MASK_DECLARE_4(x+4)
+
+const unsigned long cpu_bit_bitmap[BITS_PER_LONG+1][BITS_TO_LONGS(NR_CPUS)] = {
+
+        MASK_DECLARE_8(0),      MASK_DECLARE_8(8),
+        MASK_DECLARE_8(16),     MASK_DECLARE_8(24),
+#if BITS_PER_LONG > 32
+        MASK_DECLARE_8(32),     MASK_DECLARE_8(40),
+        MASK_DECLARE_8(48),     MASK_DECLARE_8(56),
+#endif
+};
+EXPORT_SYMBOL_GPL(cpu_bit_bitmap);