Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

Pull smpboot bugfix from Thomas Gleixner:
 "A single bugfix for a regression introduced with the conversion of the
  stop machine threads to the generic smpboot thread management
  facility"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  stop_machine: Mark per cpu stopper enabled early

diff --git a/include/linux/smpboot.h b/include/linux/smpboot.h
index c65dee059913c8d429a614bf3c9b16e088369216..13e929679550ab4967b72a73e544dbf531f74004 100644 (file)
--- a/include/linux/smpboot.h
+++ b/include/linux/smpboot.h
@@ -24,6 +24,9 @@ struct smpboot_thread_data;
  *                     parked (cpu offline)
  * @unpark:            Optional unpark function, called when the thread is
  *                     unparked (cpu online)
+ * @pre_unpark:                Optional unpark function, called before the thread is
+ *                     unparked (cpu online). This is not guaranteed to be
+ *                     called on the target cpu of the thread. Careful!
  * @selfparking:       Thread is not parked by the park function.
  * @thread_comm:       The base name of the thread
  */
@@ -37,6 +40,7 @@ struct smp_hotplug_thread {
        void                            (*cleanup)(unsigned int cpu, bool online);
        void                            (*park)(unsigned int cpu);
        void                            (*unpark)(unsigned int cpu);
+       void                            (*pre_unpark)(unsigned int cpu);
        bool                            selfparking;
        const char                      *thread_comm;
 };

diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index b9bde572782932f24d8a3a9f3a4f0670cb07b633..25d3d8b6e4e15795b21e63e3a0302027477cea58 100644 (file)
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -209,6 +209,8 @@ 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);
 }
 

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 95d178c62d5a8537c18fa2d6f1d947aed1a93448..c09f2955ae3055b42f1edde601ee1eb431bfc18a 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -336,7 +336,7 @@ static struct smp_hotplug_thread cpu_stop_threads = {
        .create                 = cpu_stop_create,
        .setup                  = cpu_stop_unpark,
        .park                   = cpu_stop_park,
-       .unpark                 = cpu_stop_unpark,
+       .pre_unpark             = cpu_stop_unpark,
        .selfparking            = true,
 };