[PATCH] file: kill unnecessary timer in fdtable_defer

free_fdtable_rc() schedules timer to reschedule fddef->wq if
schedule_work() on it returns 0.  However, schedule_work() guarantees that
the target work is executed at least once after the scheduling regardless
of its return value.  0 return simply means that the work was already
pending and thus no further action was required.

Another problem is that it used contant '5' as @expires argument to
mod_timer().

Kill unnecessary fddef->timer.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/file.c b/fs/file.c
index 3787e82..51aef67 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -21,7 +21,6 @@
 struct fdtable_defer {
        spinlock_t lock;
        struct work_struct wq;
-       struct timer_list timer;
        struct fdtable *next;
 };
 
@@ -75,22 +74,6 @@ static void __free_fdtable(struct fdtable *fdt)
        kfree(fdt);
 }
 
-static void fdtable_timer(unsigned long data)
-{
-       struct fdtable_defer *fddef = (struct fdtable_defer *)data;
-
-       spin_lock(&fddef->lock);
-       /*
-        * If someone already emptied the queue return.
-        */
-       if (!fddef->next)
-               goto out;
-       if (!schedule_work(&fddef->wq))
-               mod_timer(&fddef->timer, 5);
-out:
-       spin_unlock(&fddef->lock);
-}
-
 static void free_fdtable_work(struct work_struct *work)
 {
        struct fdtable_defer *f =
@@ -144,13 +127,8 @@ static void free_fdtable_rcu(struct rcu_head *rcu)
                spin_lock(&fddef->lock);
                fdt->next = fddef->next;
                fddef->next = fdt;
-               /*
-                * vmallocs are handled from the workqueue context.
-                * If the per-cpu workqueue is running, then we
-                * defer work scheduling through a timer.
-                */
-               if (!schedule_work(&fddef->wq))
-                       mod_timer(&fddef->timer, 5);
+               /* vmallocs are handled from the workqueue context */
+               schedule_work(&fddef->wq);
                spin_unlock(&fddef->lock);
                put_cpu_var(fdtable_defer_list);
        }
@@ -354,9 +332,6 @@ static void __devinit fdtable_defer_list_init(int cpu)
        struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu);
        spin_lock_init(&fddef->lock);
        INIT_WORK(&fddef->wq, free_fdtable_work);
-       init_timer(&fddef->timer);
-       fddef->timer.data = (unsigned long)fddef;
-       fddef->timer.function = fdtable_timer;
        fddef->next = NULL;
 }