smpboot: Remove cpumask from the API

Now that the sole use of the whole smpboot_*cpumask() API is gone,
remove it.

Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 6 insertions, 63 deletions

diff --git a/include/linux/smpboot.h b/include/linux/smpboot.h
index c174844cf663..d0884b525001 100644
--- a/include/linux/smpboot.h
+++ b/include/linux/smpboot.h
@@ -25,8 +25,6 @@ struct smpboot_thread_data;
  *                      parked (cpu offline)
  * @unpark:             Optional unpark function, called when the thread is
  *                      unparked (cpu online)
- * @cpumask:            Internal state.  To update which threads are unparked,
- *                      call smpboot_update_cpumask_percpu_thread().
  * @selfparking:        Thread is not parked by the park function.
  * @thread_comm:        The base name of the thread
  */
@@ -40,23 +38,12 @@ struct smp_hotplug_thread {
         void                            (*cleanup)(unsigned int cpu, bool online);
         void                            (*park)(unsigned int cpu);
         void                            (*unpark)(unsigned int cpu);
-        cpumask_var_t                   cpumask;
         bool                            selfparking;
         const char                      *thread_comm;
 };
 
-int smpboot_register_percpu_thread_cpumask(struct smp_hotplug_thread *plug_thread,
-                                           const struct cpumask *cpumask);
-
-static inline int
-smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
-{
-        return smpboot_register_percpu_thread_cpumask(plug_thread,
-                                                      cpu_possible_mask);
-}
+int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread);
 
 void smpboot_unregister_percpu_thread(struct smp_hotplug_thread *plug_thread);
-void smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
-                                          const struct cpumask *);
 
 #endif
diff --git a/kernel/smpboot.c b/kernel/smpboot.c
index 5043e7433f4b..c230c2dd48e1 100644
--- a/kernel/smpboot.c
+++ b/kernel/smpboot.c
@@ -238,8 +238,7 @@ int smpboot_unpark_threads(unsigned int cpu)
 
         mutex_lock(&smpboot_threads_lock);
         list_for_each_entry(cur, &hotplug_threads, list)
-                if (cpumask_test_cpu(cpu, cur->cpumask))
-                        smpboot_unpark_thread(cur, cpu);
+                smpboot_unpark_thread(cur, cpu);
         mutex_unlock(&smpboot_threads_lock);
         return 0;
 }
@@ -280,34 +279,26 @@ static void smpboot_destroy_threads(struct smp_hotplug_thread *ht)
 }
 
 /**
- * smpboot_register_percpu_thread_cpumask - Register a per_cpu thread related
+ * smpboot_register_percpu_thread - 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_cpumask(struct smp_hotplug_thread *plug_thread,
-                                           const struct cpumask *cpumask)
+int smpboot_register_percpu_thread(struct smp_hotplug_thread *plug_thread)
 {
         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;
                 }
-                if (cpumask_test_cpu(cpu, cpumask))
-                        smpboot_unpark_thread(plug_thread, cpu);
+                smpboot_unpark_thread(plug_thread, cpu);
         }
         list_add(&plug_thread->list, &hotplug_threads);
 out:
@@ -315,7 +306,7 @@ out:
         put_online_cpus();
         return ret;
 }
-EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread_cpumask);
+EXPORT_SYMBOL_GPL(smpboot_register_percpu_thread);
 
 /**
  * smpboot_unregister_percpu_thread - Unregister a per_cpu thread related to hotplug
@@ -331,44 +322,9 @@ 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.
- */
-void smpboot_update_cpumask_percpu_thread(struct smp_hotplug_thread *plug_thread,
-                                          const struct cpumask *new)
-{
-        struct cpumask *old = plug_thread->cpumask;
-        static struct cpumask tmp;
-        unsigned int cpu;
-
-        lockdep_assert_cpus_held();
-        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);
-}
-
 static DEFINE_PER_CPU(atomic_t, cpu_hotplug_state) = ATOMIC_INIT(CPU_POST_DEAD);
 
 /*