Merge branch 'master' into for-3.9-async

To receive f56c3196f251012de9b3ebaff55732a9074fdaae ("async: fix
__lowest_in_progress()").

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 23 insertions, 7 deletions

diff --git a/kernel/async.c b/kernel/async.c
index d9bf2a9b5cee..6c68fc3fae7b 100644
--- a/kernel/async.c
+++ b/kernel/async.c
@@ -88,18 +88,27 @@ static atomic_t entry_count;
  */
 static async_cookie_t  __lowest_in_progress(struct async_domain *running)
 {
+        async_cookie_t first_running = next_cookie;     /* infinity value */
+        async_cookie_t first_pending = next_cookie;     /* ditto */
         struct async_entry *entry;
 
+        /*
+         * Both running and pending lists are sorted but not disjoint.
+         * Take the first cookies from both and return the min.
+         */
         if (!list_empty(&running->domain)) {
                 entry = list_first_entry(&running->domain, typeof(*entry), list);
-                return entry->cookie;
+                first_running = entry->cookie;
         }
 
-        list_for_each_entry(entry, &async_pending, list)
-                if (entry->running == running)
-                        return entry->cookie;
+        list_for_each_entry(entry, &async_pending, list) {
+                if (entry->running == running) {
+                        first_pending = entry->cookie;
+                        break;
+                }
+        }
 
-        return next_cookie;     /* "infinity" value */
+        return min(first_running, first_pending);
 }
 
 static async_cookie_t  lowest_in_progress(struct async_domain *running)
@@ -120,13 +129,17 @@ static void async_run_entry_fn(struct work_struct *work)
 {
         struct async_entry *entry =
                 container_of(work, struct async_entry, work);
+        struct async_entry *pos;
         unsigned long flags;
         ktime_t uninitialized_var(calltime), delta, rettime;
         struct async_domain *running = entry->running;
 
-        /* 1) move self to the running queue */
+        /* 1) move self to the running queue, make sure it stays sorted */
         spin_lock_irqsave(&async_lock, flags);
-        list_move_tail(&entry->list, &running->domain);
+        list_for_each_entry_reverse(pos, &running->domain, list)
+                if (entry->cookie < pos->cookie)
+                        break;
+        list_move_tail(&entry->list, &pos->list);
         spin_unlock_irqrestore(&async_lock, flags);
 
         /* 2) run (and print duration) */
@@ -198,6 +211,9 @@ static async_cookie_t __async_schedule(async_func_ptr *ptr, void *data, struct a
         atomic_inc(&entry_count);
         spin_unlock_irqrestore(&async_lock, flags);
 
+        /* mark that this task has queued an async job, used by module init */
+        current->flags |= PF_USED_ASYNC;
+
         /* schedule for execution */
         queue_work(system_unbound_wq, &entry->work);