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-rw-r--r--include/linux/cpuset.h6
-rw-r--r--kernel/cgroup/cpuset.c41
-rw-r--r--kernel/power/process.c2
-rw-r--r--kernel/sched/core.c1
4 files changed, 30 insertions, 20 deletions
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)
+void cpuset_update_active_cpus(void)
{
- cpuset_hotplug(true);
+ /*
+ * 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_update_active_cpus(void)
+void cpuset_wait_for_hotplug(void)
{
- cpuset_hotplug(false);
+ 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();
}