diff options
| -rw-r--r-- | include/linux/cpu.h | 5 | ||||
| -rw-r--r-- | include/linux/cpuhotplug.h | 1 | ||||
| -rw-r--r-- | kernel/cpu.c | 16 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 5 |
4 files changed, 17 insertions, 10 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 83f35767016d..91a48d1b4ca0 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -276,14 +276,15 @@ void arch_cpu_idle_enter(void); void arch_cpu_idle_exit(void); void arch_cpu_idle_dead(void); -DECLARE_PER_CPU(bool, cpu_dead_idle); - int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); #ifdef CONFIG_HOTPLUG_CPU bool cpu_wait_death(unsigned int cpu, int seconds); bool cpu_report_death(void); +void cpuhp_report_idle_dead(void); +#else +static inline void cpuhp_report_idle_dead(void) { } #endif /* #ifdef CONFIG_HOTPLUG_CPU */ #endif /* _LINUX_CPU_H_ */ diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index ad5d7fcb0130..5d68e15e46b7 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -6,6 +6,7 @@ enum cpuhp_state { CPUHP_CREATE_THREADS, CPUHP_NOTIFY_PREPARE, CPUHP_BRINGUP_CPU, + CPUHP_AP_IDLE_DEAD, CPUHP_AP_OFFLINE, CPUHP_AP_NOTIFY_STARTING, CPUHP_AP_ONLINE, diff --git a/kernel/cpu.c b/kernel/cpu.c index f1f880fac832..0e8c07f2566e 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -688,6 +688,7 @@ static int take_cpu_down(void *_param) static int takedown_cpu(unsigned int cpu) { + struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu); int err; /* @@ -733,10 +734,8 @@ static int takedown_cpu(unsigned int cpu) * * Wait for the stop thread to go away. */ - while (!per_cpu(cpu_dead_idle, cpu)) - cpu_relax(); - smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */ - per_cpu(cpu_dead_idle, cpu) = false; + wait_for_completion(&st->done); + BUG_ON(st->state != CPUHP_AP_IDLE_DEAD); /* Interrupts are moved away from the dying cpu, reenable alloc/free */ irq_unlock_sparse(); @@ -756,6 +755,15 @@ static int notify_dead(unsigned int cpu) return 0; } +void cpuhp_report_idle_dead(void) +{ + struct cpuhp_cpu_state *st = this_cpu_ptr(&cpuhp_state); + + BUG_ON(st->state != CPUHP_AP_OFFLINE); + st->state = CPUHP_AP_IDLE_DEAD; + complete(&st->done); +} + #else #define notify_down_prepare NULL #define takedown_cpu NULL diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index a4b9813afc96..8abbe89e9114 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -194,8 +194,6 @@ exit_idle: rcu_idle_exit(); } -DEFINE_PER_CPU(bool, cpu_dead_idle); - /* * Generic idle loop implementation * @@ -224,8 +222,7 @@ static void cpu_idle_loop(void) if (cpu_is_offline(smp_processor_id())) { rcu_cpu_notify(NULL, CPU_DYING_IDLE, (void *)(long)smp_processor_id()); - smp_mb(); /* all activity before dead. */ - this_cpu_write(cpu_dead_idle, true); + cpuhp_report_idle_dead(); arch_cpu_idle_dead(); } |