diff options
| -rw-r--r-- | kernel/cpu.c | 33 |
1 files changed, 26 insertions, 7 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 6ea42e8da861..3e3f6e49eabb 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -36,6 +36,7 @@ * @target: The target state * @thread: Pointer to the hotplug thread * @should_run: Thread should execute + * @rollback: Perform a rollback * @cb_stat: The state for a single callback (install/uninstall) * @cb: Single callback function (install/uninstall) * @result: Result of the operation @@ -47,6 +48,7 @@ struct cpuhp_cpu_state { #ifdef CONFIG_SMP struct task_struct *thread; bool should_run; + bool rollback; enum cpuhp_state cb_state; int (*cb)(unsigned int cpu); int result; @@ -301,6 +303,11 @@ static int cpu_notify(unsigned long val, unsigned int cpu) return __cpu_notify(val, cpu, -1, NULL); } +static void cpu_notify_nofail(unsigned long val, unsigned int cpu) +{ + BUG_ON(cpu_notify(val, cpu)); +} + /* Notifier wrappers for transitioning to state machine */ static int notify_prepare(unsigned int cpu) { @@ -477,6 +484,16 @@ static void cpuhp_thread_fun(unsigned int cpu) } else { ret = cpuhp_invoke_callback(cpu, st->cb_state, st->cb); } + } else if (st->rollback) { + BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); + + undo_cpu_down(cpu, st, cpuhp_ap_states); + /* + * This is a momentary workaround to keep the notifier users + * happy. Will go away once we got rid of the notifiers. + */ + cpu_notify_nofail(CPU_DOWN_FAILED, cpu); + st->rollback = false; } else { /* Cannot happen .... */ BUG_ON(st->state < CPUHP_AP_ONLINE_IDLE); @@ -636,11 +653,6 @@ static inline void check_for_tasks(int dead_cpu) read_unlock(&tasklist_lock); } -static void cpu_notify_nofail(unsigned long val, unsigned int cpu) -{ - BUG_ON(cpu_notify(val, cpu)); -} - static int notify_down_prepare(unsigned int cpu) { int err, nr_calls = 0; @@ -721,9 +733,10 @@ static int takedown_cpu(unsigned int cpu) */ err = stop_machine(take_cpu_down, NULL, cpumask_of(cpu)); if (err) { - /* CPU didn't die: tell everyone. Can't complain. */ - cpu_notify_nofail(CPU_DOWN_FAILED, cpu); + /* CPU refused to die */ irq_unlock_sparse(); + /* Unpark the hotplug thread so we can rollback there */ + kthread_unpark(per_cpu_ptr(&cpuhp_state, cpu)->thread); return err; } BUG_ON(cpu_online(cpu)); @@ -832,6 +845,11 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, * to do the further cleanups. */ ret = cpuhp_down_callbacks(cpu, st, cpuhp_bp_states, target); + if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { + st->target = prev_state; + st->rollback = true; + cpuhp_kick_ap_work(cpu); + } hasdied = prev_state != st->state && st->state == CPUHP_OFFLINE; out: @@ -1249,6 +1267,7 @@ static struct cpuhp_step cpuhp_ap_states[] = { .name = "notify:online", .startup = notify_online, .teardown = notify_down_prepare, + .skip_onerr = true, }, #endif /* |