diff options
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 31 |
1 files changed, 10 insertions, 21 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 6ba0f1e..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, ¤t->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(); @@ -383,19 +371,20 @@ 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; |
