diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 2ab910f85154..1b8e41597ef5 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -52,7 +52,9 @@ static inline void cpuset_dec(void) extern int cpuset_init(void); extern void cpuset_init_smp(void); +extern void cpuset_force_rebuild(void); extern void cpuset_update_active_cpus(void); +extern void cpuset_wait_for_hotplug(void); extern void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask); extern void cpuset_cpus_allowed_fallback(struct task_struct *p); extern nodemask_t cpuset_mems_allowed(struct task_struct *p); @@ -165,11 +167,15 @@ static inline bool cpusets_enabled(void) { return false; } static inline int cpuset_init(void) { return 0; } static inline void cpuset_init_smp(void) {} +static inline void cpuset_force_rebuild(void) { } + static inline void cpuset_update_active_cpus(void) { partition_sched_domains(1, NULL, NULL); } +static inline void cpuset_wait_for_hotplug(void) { } + static inline void cpuset_cpus_allowed(struct task_struct *p, struct cpumask *mask) { diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index 227bc25d951d..cab5fd1ee767 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -2277,8 +2277,15 @@ retry: mutex_unlock(&cpuset_mutex); } +static bool force_rebuild; + +void cpuset_force_rebuild(void) +{ + force_rebuild = true; +} + /** - * cpuset_hotplug - handle CPU/memory hotunplug for a cpuset + * cpuset_hotplug_workfn - handle CPU/memory hotunplug for a cpuset * * This function is called after either CPU or memory configuration has * changed and updates cpuset accordingly. The top_cpuset is always @@ -2293,7 +2300,7 @@ retry: * Note that CPU offlining during suspend is ignored. We don't modify * cpusets across suspend/resume cycles at all. */ -static void cpuset_hotplug(bool use_cpu_hp_lock) +static void cpuset_hotplug_workfn(struct work_struct *work) { static cpumask_t new_cpus; static nodemask_t new_mems; @@ -2351,31 +2358,25 @@ static void cpuset_hotplug(bool use_cpu_hp_lock) } /* rebuild sched domains if cpus_allowed has changed */ - if (cpus_updated) { - if (use_cpu_hp_lock) - rebuild_sched_domains(); - else { - /* Acquiring cpu_hotplug_lock is not required. - * When cpuset_hotplug() is called in hotplug path, - * cpu_hotplug_lock is held by the hotplug context - * which is waiting for cpuhp_thread_fun to indicate - * completion of callback. - */ - mutex_lock(&cpuset_mutex); - rebuild_sched_domains_cpuslocked(); - mutex_unlock(&cpuset_mutex); - } + if (cpus_updated || force_rebuild) { + force_rebuild = false; + rebuild_sched_domains(); } } -static void cpuset_hotplug_workfn(struct work_struct *work) -{ - cpuset_hotplug(true); -} - void cpuset_update_active_cpus(void) { - cpuset_hotplug(false); + /* + * We're inside cpu hotplug critical region which usually nests + * inside cgroup synchronization. Bounce actual hotplug processing + * to a work item to avoid reverse locking order. + */ + schedule_work(&cpuset_hotplug_work); +} + +void cpuset_wait_for_hotplug(void) +{ + flush_work(&cpuset_hotplug_work); } /* diff --git a/kernel/power/process.c b/kernel/power/process.c index c326d7235c5f..7381d49a44db 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -204,6 +204,8 @@ void thaw_processes(void) __usermodehelper_set_disable_depth(UMH_FREEZING); thaw_workqueues(); + cpuset_wait_for_hotplug(); + read_lock(&tasklist_lock); for_each_process_thread(g, p) { /* No other threads should have PF_SUSPEND_TASK set */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 88b3450b29ab..75554f366fd3 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5624,6 +5624,7 @@ static void cpuset_cpu_active(void) * restore the original sched domains by considering the * cpuset configurations. */ + cpuset_force_rebuild(); } cpuset_update_active_cpus(); }