Split out into separate functions, so we can convert it to a state machine. Signed-off-by: Thomas Gleixner --- kernel/cpu.c | 69 ++++++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 47 insertions(+), 22 deletions(-) Index: linux-2.6/kernel/cpu.c =================================================================== --- linux-2.6.orig/kernel/cpu.c +++ linux-2.6/kernel/cpu.c @@ -168,6 +168,43 @@ static int cpu_notify(unsigned long val, return __cpu_notify(val, cpu, -1, NULL); } +/* Notifier wrappers for transitioning to state machine */ +static int notify_prepare(unsigned int cpu) +{ + int nr_calls = 0; + int ret; + + ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); + if (ret) { + nr_calls--; + printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", + __func__, cpu); + __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); + } + return ret; +} + +static int notify_online(unsigned int cpu) +{ + cpu_notify(CPU_ONLINE, cpu); + return 0; +} + +static int bringup_cpu(unsigned int cpu) +{ + struct task_struct *idle = idle_thread_get(cpu); + int ret; + + /* Arch-specific enabling code. */ + ret = __cpu_up(cpu, idle); + if (ret) { + cpu_notify(CPU_UP_CANCELED, cpu); + return ret; + } + BUG_ON(!cpu_online(cpu)); + return 0; +} + #ifdef CONFIG_HOTPLUG_CPU static void cpu_notify_nofail(unsigned long val, unsigned int cpu) @@ -340,7 +377,7 @@ EXPORT_SYMBOL(cpu_down); static int __cpuinit _cpu_up(unsigned int cpu, int tasks_frozen) { struct task_struct *idle; - int ret, nr_calls = 0; + int ret; cpu_hotplug_begin(); @@ -355,35 +392,23 @@ static int __cpuinit _cpu_up(unsigned in goto out; } + cpuhp_tasks_frozen = tasks_frozen; + ret = smpboot_create_threads(cpu); if (ret) goto out; - cpuhp_tasks_frozen = tasks_frozen; - - ret = __cpu_notify(CPU_UP_PREPARE, cpu, -1, &nr_calls); - if (ret) { - nr_calls--; - printk(KERN_WARNING "%s: attempt to bring up CPU %u failed\n", - __func__, cpu); - goto out_notify; - } + ret = notify_prepare(cpu); + if (ret) + goto out; - /* Arch-specific enabling code. */ - ret = __cpu_up(cpu, idle); - if (ret != 0) - goto out_notify; - BUG_ON(!cpu_online(cpu)); + ret = bringup_cpu(cpu); + if (ret) + goto out; /* Wake the per cpu threads */ smpboot_unpark_threads(cpu); - - /* Now call notifier in preparation. */ - cpu_notify(CPU_ONLINE, cpu); - -out_notify: - if (ret != 0) - __cpu_notify(CPU_UP_CANCELED, cpu, nr_calls, NULL); + notify_online(cpu); out: cpu_hotplug_done();