diff options
Diffstat (limited to 'kernel/smpboot.c')
| -rw-r--r-- | kernel/smpboot.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 2efe1e206167..2c7396da470c 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -33,7 +33,6 @@ struct task_struct *idle_thread_get(unsigned int cpu) if (!tsk) return ERR_PTR(-ENOMEM); - init_idle(tsk, cpu); return tsk; } @@ -48,7 +47,7 @@ void __init idle_thread_set_boot_cpu(void) * * Creates the thread if it does not exist. */ -static inline void idle_init(unsigned int cpu) +static __always_inline void idle_init(unsigned int cpu) { struct task_struct *tsk = per_cpu(idle_threads, cpu); @@ -188,6 +187,7 @@ __smpboot_create_thread(struct smp_hotplug_thread *ht, unsigned int cpu) kfree(td); return PTR_ERR(tsk); } + kthread_set_per_cpu(tsk, cpu); /* * Park the thread so that it could start right on the CPU * when it is available. @@ -291,7 +291,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) unsigned int cpu; int ret = 0; - get_online_cpus(); + cpus_read_lock(); mutex_lock(&smpboot_threads_lock); for_each_online_cpu(cpu) { ret = __smpboot_create_thread(plug_thread, cpu); @@ -304,7 +304,7 @@ int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread) list_add(&plug_thread->list, &hotplug_threads); out: mutex_unlock(&smpboot_threads_lock); - put_online_cpus(); + cpus_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); @@ -317,12 +317,12 @@ EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread); */ void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread) { - get_online_cpus(); + cpus_read_lock(); mutex_lock(&smpboot_threads_lock); list_del(&plug_thread->list); smpboot_destroy_threads(plug_thread); mutex_unlock(&smpboot_threads_lock); - put_online_cpus(); + cpus_read_unlock(); } EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread); @@ -392,6 +392,13 @@ int cpu_check_up_prepare(int cpu) */ return -EAGAIN; + case CPU_UP_PREPARE: + /* + * Timeout while waiting for the CPU to show up. Allow to try + * again later. + */ + return 0; + default: /* Should not happen. Famous last words. */ @@ -426,7 +433,7 @@ bool cpu_wait_death(unsigned int cpu, int seconds) /* The outgoing CPU will normally get done quite quickly. */ if (atomic_read(&per_cpu(cpu_hotplug_state, cpu)) == CPU_DEAD) - goto update_state; + goto update_state_early; udelay(5); /* But if the outgoing CPU dawdles, wait increasingly long times. */ @@ -437,16 +444,17 @@ bool cpu_wait_death(unsigned int cpu, int seconds) break; sleep_jf = DIV_ROUND_UP(sleep_jf * 11, 10); } -update_state: +update_state_early: oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); +update_state: if (oldstate == CPU_DEAD) { /* Outgoing CPU died normally, update state. */ smp_mb(); /* atomic_read() before update. */ atomic_set(&per_cpu(cpu_hotplug_state, cpu), CPU_POST_DEAD); } else { /* Outgoing CPU still hasn't died, set state accordingly. */ - if (atomic_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - oldstate, CPU_BROKEN) != oldstate) + if (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), + &oldstate, CPU_BROKEN)) goto update_state; ret = false; } @@ -468,14 +476,14 @@ bool cpu_report_death(void) int newstate; int cpu = smp_processor_id(); + oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); do { - oldstate = atomic_read(&per_cpu(cpu_hotplug_state, cpu)); if (oldstate != CPU_BROKEN) newstate = CPU_DEAD; else newstate = CPU_DEAD_FROZEN; - } while (atomic_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), - oldstate, newstate) != oldstate); + } while (!atomic_try_cmpxchg(&per_cpu(cpu_hotplug_state, cpu), + &oldstate, newstate)); return newstate == CPU_DEAD; } |