diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index ce5b3ffbd6ee..878ed43d8753 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -494,7 +494,8 @@ static const struct attribute_group *cpu_root_attr_groups[] = { bool cpu_is_hotpluggable(unsigned cpu) { struct device *dev = get_cpu_device(cpu); - return dev && container_of(dev, struct cpu, dev)->hotpluggable; + return dev && container_of(dev, struct cpu, dev)->hotpluggable + && tick_nohz_cpu_hotpluggable(cpu); } EXPORT_SYMBOL_GPL(cpu_is_hotpluggable); diff --git a/include/linux/tick.h b/include/linux/tick.h index 965163bdfe41..443726085f6c 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -197,6 +197,7 @@ extern void tick_nohz_dep_set_signal(struct signal_struct *signal, enum tick_dep_bits bit); extern void tick_nohz_dep_clear_signal(struct signal_struct *signal, enum tick_dep_bits bit); +extern bool tick_nohz_cpu_hotpluggable(unsigned int cpu); /* * The below are tick_nohz_[set,clear]_dep() wrappers that optimize off-cases @@ -261,6 +262,7 @@ static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { } static inline void tick_nohz_dep_set_cpu(int cpu, enum tick_dep_bits bit) { } static inline void tick_nohz_dep_clear_cpu(int cpu, enum tick_dep_bits bit) { } +static inline bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { return true; } static inline void tick_dep_set(enum tick_dep_bits bit) { } static inline void tick_dep_clear(enum tick_dep_bits bit) { } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 7228bdd2eabe..25c6efa2c557 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -406,7 +406,7 @@ void __init tick_nohz_full_setup(cpumask_var_t cpumask) tick_nohz_full_running = true; } -static int tick_nohz_cpu_down(unsigned int cpu) +bool tick_nohz_cpu_hotpluggable(unsigned int cpu) { /* * The boot CPU handles housekeeping duty (unbound timers, @@ -414,8 +414,13 @@ static int tick_nohz_cpu_down(unsigned int cpu) * CPUs. It must remain online when nohz full is enabled. */ if (tick_nohz_full_running && tick_do_timer_cpu == cpu) - return -EBUSY; - return 0; + return false; + return true; +} + +static int tick_nohz_cpu_down(unsigned int cpu) +{ + return tick_nohz_cpu_hotpluggable(cpu) ? 0 : -EBUSY; } void __init tick_nohz_init(void)