Merge branch 'master' of /home/trondmy/kernel/linux-2.6/ into merge_linus

1 files changed, 100 insertions, 8 deletions

diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 8d1e7cb8a51a..6b186750e9be 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -29,6 +29,9 @@
 #include <linux/kthread.h>
 #include <linux/hardirq.h>
 #include <linux/mempolicy.h>
+#include <linux/freezer.h>
+#include <linux/kallsyms.h>
+#include <linux/debug_locks.h>
 
 /*
  * The per-CPU workqueue (if single thread, we always use the first
@@ -55,6 +58,8 @@ struct cpu_workqueue_struct {
         struct task_struct *thread;
 
         int run_depth;          /* Detect run_workqueue() recursion depth */
+
+        int freezeable;         /* Freeze the thread during suspend */
 } ____cacheline_aligned;
 
 /*
@@ -103,6 +108,79 @@ static inline void *get_wq_data(struct work_struct *work)
         return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK);
 }
 
+static int __run_work(struct cpu_workqueue_struct *cwq, struct work_struct *work)
+{
+        int ret = 0;
+        unsigned long flags;
+
+        spin_lock_irqsave(&cwq->lock, flags);
+        /*
+         * We need to re-validate the work info after we've gotten
+         * the cpu_workqueue lock. We can run the work now iff:
+         *
+         *  - the wq_data still matches the cpu_workqueue_struct
+         *  - AND the work is still marked pending
+         *  - AND the work is still on a list (which will be this
+         *    workqueue_struct list)
+         *
+         * All these conditions are important, because we
+         * need to protect against the work being run right
+         * now on another CPU (all but the last one might be
+         * true if it's currently running and has not been
+         * released yet, for example).
+         */
+        if (get_wq_data(work) == cwq
+            && work_pending(work)
+            && !list_empty(&work->entry)) {
+                work_func_t f = work->func;
+                list_del_init(&work->entry);
+                spin_unlock_irqrestore(&cwq->lock, flags);
+
+                if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management))
+                        work_release(work);
+                f(work);
+
+                spin_lock_irqsave(&cwq->lock, flags);
+                cwq->remove_sequence++;
+                wake_up(&cwq->work_done);
+                ret = 1;
+        }
+        spin_unlock_irqrestore(&cwq->lock, flags);
+        return ret;
+}
+
+/**
+ * run_scheduled_work - run scheduled work synchronously
+ * @work: work to run
+ *
+ * This checks if the work was pending, and runs it
+ * synchronously if so. It returns a boolean to indicate
+ * whether it had any scheduled work to run or not.
+ *
+ * NOTE! This _only_ works for normal work_structs. You
+ * CANNOT use this for delayed work, because the wq data
+ * for delayed work will not point properly to the per-
+ * CPU workqueue struct, but will change!
+ */
+int fastcall run_scheduled_work(struct work_struct *work)
+{
+        for (;;) {
+                struct cpu_workqueue_struct *cwq;
+
+                if (!work_pending(work))
+                        return 0;
+                if (list_empty(&work->entry))
+                        return 0;
+                /* NOTE! This depends intimately on __queue_work! */
+                cwq = get_wq_data(work);
+                if (!cwq)
+                        return 0;
+                if (__run_work(cwq, work))
+                        return 1;
+        }
+}
+EXPORT_SYMBOL(run_scheduled_work);
+
 /* Preempt must be disabled. */
 static void __queue_work(struct cpu_workqueue_struct *cwq,
                          struct work_struct *work)
@@ -250,6 +328,17 @@ static void run_workqueue(struct cpu_workqueue_struct *cwq)
                         work_release(work);
                 f(work);
 
+                if (unlikely(in_atomic() || lockdep_depth(current) > 0)) {
+                        printk(KERN_ERR "BUG: workqueue leaked lock or atomic: "
+                                        "%s/0x%08x/%d\n",
+                                        current->comm, preempt_count(),
+                                        current->pid);
+                        printk(KERN_ERR "    last function: ");
+                        print_symbol("%s\n", (unsigned long)f);
+                        debug_show_held_locks(current);
+                        dump_stack();
+                }
+
                 spin_lock_irqsave(&cwq->lock, flags);
                 cwq->remove_sequence++;
                 wake_up(&cwq->work_done);
@@ -265,7 +354,8 @@ static int worker_thread(void *__cwq)
         struct k_sigaction sa;
         sigset_t blocked;
 
-        current->flags |= PF_NOFREEZE;
+        if (!cwq->freezeable)
+                current->flags |= PF_NOFREEZE;
 
         set_user_nice(current, -5);
 
@@ -288,6 +378,9 @@ static int worker_thread(void *__cwq)
 
         set_current_state(TASK_INTERRUPTIBLE);
         while (!kthread_should_stop()) {
+                if (cwq->freezeable)
+                        try_to_freeze();
+
                 add_wait_queue(&cwq->more_work, &wait);
                 if (list_empty(&cwq->worklist))
                         schedule();
@@ -364,7 +457,7 @@ void fastcall flush_workqueue(struct workqueue_struct *wq)
 EXPORT_SYMBOL_GPL(flush_workqueue);
 
 static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
-                                                   int cpu)
+                                                   int cpu, int freezeable)
 {
         struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
         struct task_struct *p;
@@ -374,6 +467,7 @@ static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
         cwq->thread = NULL;
         cwq->insert_sequence = 0;
         cwq->remove_sequence = 0;
+        cwq->freezeable = freezeable;
         INIT_LIST_HEAD(&cwq->worklist);
         init_waitqueue_head(&cwq->more_work);
         init_waitqueue_head(&cwq->work_done);
@@ -389,7 +483,7 @@ static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
 }
 
 struct workqueue_struct *__create_workqueue(const char *name,
-                                            int singlethread)
+                                            int singlethread, int freezeable)
 {
         int cpu, destroy = 0;
         struct workqueue_struct *wq;
@@ -409,7 +503,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
         mutex_lock(&workqueue_mutex);
         if (singlethread) {
                 INIT_LIST_HEAD(&wq->list);
-                p = create_workqueue_thread(wq, singlethread_cpu);
+                p = create_workqueue_thread(wq, singlethread_cpu, freezeable);
                 if (!p)
                         destroy = 1;
                 else
@@ -417,7 +511,7 @@ struct workqueue_struct *__create_workqueue(const char *name,
         } else {
                 list_add(&wq->list, &workqueues);
                 for_each_online_cpu(cpu) {
-                        p = create_workqueue_thread(wq, cpu);
+                        p = create_workqueue_thread(wq, cpu, freezeable);
                         if (p) {
                                 kthread_bind(p, cpu);
                                 wake_up_process(p);
@@ -634,7 +728,6 @@ int current_is_keventd(void)
 
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 /* Take the work from this (downed) CPU. */
 static void take_over_work(struct workqueue_struct *wq, unsigned int cpu)
 {
@@ -667,7 +760,7 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
                 mutex_lock(&workqueue_mutex);
                 /* Create a new workqueue thread for it. */
                 list_for_each_entry(wq, &workqueues, list) {
-                        if (!create_workqueue_thread(wq, hotcpu)) {
+                        if (!create_workqueue_thread(wq, hotcpu, 0)) {
                                 printk("workqueue for %i failed\n", hotcpu);
                                 return NOTIFY_BAD;
                         }
@@ -717,7 +810,6 @@ static int __devinit workqueue_cpu_callback(struct notifier_block *nfb,
 
         return NOTIFY_OK;
 }
-#endif
 
 void init_workqueues(void)
 {