These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / kernel / smpboot.c

diff --git a/kernel/kernel/smpboot.c b/kernel/kernel/smpboot.c
index c697f73..d264f59 100644 (file)
--- a/kernel/kernel/smpboot.c
+++ b/kernel/kernel/smpboot.c
@@ -113,7 +113,8 @@ static int smpboot_thread_fn(void *data)
                if (kthread_should_stop()) {
                        __set_current_state(TASK_RUNNING);
                        preempt_enable();
-                       if (ht->cleanup)
+                       /* cleanup must mirror setup */
+                       if (ht->cleanup && td->status != HP_THREAD_NONE)
                                ht->cleanup(td->cpu, cpu_online(td->cpu));
                        kfree(td);
                        return 0;
@@ -221,9 +222,8 @@ static void smpboot_unpark_thread(struct smp_hotplug_thread *ht, unsigned int cp
 {
        struct task_struct *tsk = *per_cpu_ptr(ht->store, cpu);
 
-       if (ht->pre_unpark)
-               ht->pre_unpark(cpu);
-       kthread_unpark(tsk);
+       if (!ht->selfparking)
+               kthread_unpark(tsk);
 }
 
 void smpboot_unpark_threads(unsigned int cpu)
@@ -232,7 +232,8 @@ void smpboot_unpark_threads(unsigned int cpu)
 
        mutex_lock(&smpboot_threads_lock);
        list_for_each_entry(cur, &hotplug_threads, list)
-               smpboot_unpark_thread(cur, cpu);
+               if (cpumask_test_cpu(cpu, cur->cpumask))
+                       smpboot_unpark_thread(cur, cpu);
        mutex_unlock(&smpboot_threads_lock);
 }
 
@@ -271,25 +272,34 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)
 }
 
 /**
- * smpboot_register_percpu_thread - Register a per_cpu thread related to hotplug
+ * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related
+ *                                         to hotplug
  * @plug_thread:       Hotplug thread descriptor
+ * @cpumask:           The cpumask where threads run
  *
  * Creates and starts the threads on all online cpus.
  */
-int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
+int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
+                                          const struct cpumask *cpumask)
 {
        unsigned int cpu;
        int ret = 0;
 
+       if (!alloc_cpumask_var(&plug_thread->cpumask, GFP_KERNEL))
+               return -ENOMEM;
+       cpumask_copy(plug_thread->cpumask, cpumask);
+
        get_online_cpus();
        mutex_lock(&smpboot_threads_lock);
        for_each_online_cpu(cpu) {
                ret = __smpboot_create_thread(plug_thread, cpu);
                if (ret) {
                        smpboot_destroy_threads(plug_thread);
+                       free_cpumask_var(plug_thread->cpumask);
                        goto out;
                }
-               smpboot_unpark_thread(plug_thread, cpu);
+               if (cpumask_test_cpu(cpu, cpumask))
+                       smpboot_unpark_thread(plug_thread, cpu);
        }
        list_add(&plug_thread->list, &hotplug_threads);
 out:
@@ -297,7 +307,7 @@ out:
        put_online_cpus();
        return ret;
 }
-EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
+EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask);
 
 /**
  * smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug
@@ -313,9 +323,53 @@ void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread)
        smpboot_destroy_threads(plug_thread);
        mutex_unlock(&smpboot_threads_lock);
        put_online_cpus();
+       free_cpumask_var(plug_thread->cpumask);
 }
 EXPORT_SYMBOL_GPL(smpboot_unregister_percpu_thread);
 
+/**
+ * smpboot_update_cpumask_percpu_thread - Adjust which per_cpu hotplug threads stay parked
+ * @plug_thread:       Hotplug thread descriptor
+ * @new:               Revised mask to use
+ *
+ * The cpumask field in the smp_hotplug_thread must not be updated directly
+ * by the client, but only by calling this function.
+ * This function can only be called on a registered smp_hotplug_thread.
+ */
+int smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
+                                        const struct cpumask *new)
+{
+       struct cpumask *old = plug_thread->cpumask;
+       cpumask_var_t tmp;
+       unsigned int cpu;
+
+       if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
+               return -ENOMEM;
+
+       get_online_cpus();
+       mutex_lock(&smpboot_threads_lock);
+
+       /* Park threads that were exclusively enabled on the old mask. */
+       cpumask_andnot(tmp, old, new);
+       for_each_cpu_and(cpu, tmp, cpu_online_mask)
+               smpboot_park_thread(plug_thread, cpu);
+
+       /* Unpark threads that are exclusively enabled on the new mask. */
+       cpumask_andnot(tmp, new, old);
+       for_each_cpu_and(cpu, tmp, cpu_online_mask)
+               smpboot_unpark_thread(plug_thread, cpu);
+
+       cpumask_copy(old, new);
+
+       mutex_unlock(&smpboot_threads_lock);
+       put_online_cpus();
+
+       free_cpumask_var(tmp);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(smpboot_update_cpumask_percpu_thread);
+
 static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) = ATOMIC_INIT(CPU_POST_DEAD);
 
 /*