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-rw-r--r--kernel/cpu.c26
1 files changed, 8 insertions, 18 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 7c4e271..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();
@@ -383,10 +371,12 @@ 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)
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