X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=kernel%2Fcpu.c;h=1c8ddd6ee9402fdf2f6853c6142f3a8d0cb57da6;hp=f5f9485b8c0f9a30f4084b0c9a8846f74e05d72d;hb=e071041be037eca208b62b84469a06bdfc692bea;hpb=d0af9eed5aa91b6b7b5049cae69e5ea956fd85c3

diff --git a/kernel/cpu.c b/kernel/cpu.c
index f5f9485..1c8ddd6 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -209,9 +209,12 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 		return -ENOMEM;
 
 	cpu_hotplug_begin();
+	set_cpu_active(cpu, false);
 	err = __raw_notifier_call_chain(&cpu_chain, CPU_DOWN_PREPARE | mod,
 					hcpu, -1, &nr_calls);
 	if (err == NOTIFY_BAD) {
+		set_cpu_active(cpu, true);
+
 		nr_calls--;
 		__raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
 					  hcpu, nr_calls, NULL);
@@ -223,11 +226,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
 
 	/* Ensure that we are not runnable on dying cpu */
 	cpumask_copy(old_allowed, &current->cpus_allowed);
-	set_cpus_allowed_ptr(current,
-			     cpumask_of(cpumask_any_but(cpu_online_mask, cpu)));
+	set_cpus_allowed_ptr(current, cpu_active_mask);
 
 	err = __stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
 	if (err) {
+		set_cpu_active(cpu, true);
 		/* CPU didn't die: tell everyone.  Can't complain. */
 		if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
 					    hcpu) == NOTIFY_BAD)
@@ -278,23 +281,8 @@ int __ref cpu_down(unsigned int cpu)
 		goto out;
 	}
 
-	set_cpu_active(cpu, false);
-
-	/*
-	 * Make sure the all cpus did the reschedule and are not
-	 * using stale version of the cpu_active_mask.
-	 * This is not strictly necessary becuase stop_machine()
-	 * that we run down the line already provides the required
-	 * synchronization. But it's really a side effect and we do not
-	 * want to depend on the innards of the stop_machine here.
-	 */
-	synchronize_sched();
-
 	err = _cpu_down(cpu, 0);
 
-	if (cpu_online(cpu))
-		set_cpu_active(cpu, true);
-
 out:
 	cpu_maps_update_done();
 	stop_machine_destroy();
@@ -383,24 +371,26 @@ int disable_nonboot_cpus(void)
 		return error;
 	cpu_maps_update_begin();
 	first_cpu = cpumask_first(cpu_online_mask);
-	/* We take down all of the non-boot CPUs in one shot to avoid races
+	/*
+	 * We take down all of the non-boot CPUs in one shot to avoid races
 	 * with the userspace trying to use the CPU hotplug at the same time
 	 */
 	cpumask_clear(frozen_cpus);
+
 	printk("Disabling non-boot CPUs ...\n");
 	for_each_online_cpu(cpu) {
 		if (cpu == first_cpu)
 			continue;
 		error = _cpu_down(cpu, 1);
-		if (!error) {
+		if (!error)
 			cpumask_set_cpu(cpu, frozen_cpus);
-			printk("CPU%d is down\n", cpu);
-		} else {
+		else {
 			printk(KERN_ERR "Error taking CPU%d down: %d\n",
 				cpu, error);
 			break;
 		}
 	}
+
 	if (!error) {
 		BUG_ON(num_online_cpus() > 1);
 		/* Make sure the CPUs won't be enabled by someone else */