Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 24 insertions, 10 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 880fb415a8f6..565cf7a1febd 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -428,22 +428,34 @@ int schedule_delayed_work_on(int cpu,
         return ret;
 }
 
-int schedule_on_each_cpu(void (*func) (void *info), void *info)
+/**
+ * schedule_on_each_cpu - call a function on each online CPU from keventd
+ * @func: the function to call
+ * @info: a pointer to pass to func()
+ *
+ * Returns zero on success.
+ * Returns -ve errno on failure.
+ *
+ * Appears to be racy against CPU hotplug.
+ *
+ * schedule_on_each_cpu() is very slow.
+ */
+int schedule_on_each_cpu(void (*func)(void *info), void *info)
 {
         int cpu;
-        struct work_struct *work;
+        struct work_struct *works;
 
-        work = kmalloc(NR_CPUS * sizeof(struct work_struct), GFP_KERNEL);
-
-        if (!work)
+        works = alloc_percpu(struct work_struct);
+        if (!works)
                 return -ENOMEM;
+
         for_each_online_cpu(cpu) {
-                INIT_WORK(work + cpu, func, info);
+                INIT_WORK(per_cpu_ptr(works, cpu), func, info);
                 __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu),
-                                work + cpu);
+                                per_cpu_ptr(works, cpu));
         }
         flush_workqueue(keventd_wq);
-        kfree(work);
+        free_percpu(works);
         return 0;
 }
 
@@ -531,11 +543,11 @@ int current_is_keventd(void)
 static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
 {
         struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
-        LIST_HEAD(list);
+        struct list_head list;
         struct work_struct *work;
 
         spin_lock_irq(&cwq->lock);
-        list_splice_init(&cwq->worklist, &list);
+        list_replace_init(&cwq->worklist, &list);
 
         while (!list_empty(&list)) {
                 printk("Taking work for %s\n", wq->name);
@@ -578,6 +590,8 @@ static int workqueue_cpu_callback(struct notifier_block *nfb,
 
         case CPU_UP_CANCELED:
                 list_for_each_entry(wq, &workqueues, list) {
+                        if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread)
+                                continue;
                         /* Unbind so it can run. */
                         kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread,
                                      any_online_cpu(cpu_online_map));