[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>

1 files changed, 2 insertions, 27 deletions

diff --git a/fs/file.c b/fs/file.c
index 3787e82f54c1..51aef675470f 100644
--- 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;
 }