ALSA: nm256: More constifications

[linux.git] / fs / eventpoll.c

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index c4159bcc05d9a514cacd620a08602dd76635e42d..67a395039268063e3776d50ce7be6f0c5c6cff6f 100644 (file)
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -551,28 +551,23 @@ static int ep_call_nested(struct nested_calls *ncalls,
  */
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 
-static struct nested_calls poll_safewake_ncalls;
-
-static int ep_poll_wakeup_proc(void *priv, void *cookie, int call_nests)
-{
-       unsigned long flags;
-       wait_queue_head_t *wqueue = (wait_queue_head_t *)cookie;
-
-       spin_lock_irqsave_nested(&wqueue->lock, flags, call_nests + 1);
-       wake_up_locked_poll(wqueue, EPOLLIN);
-       spin_unlock_irqrestore(&wqueue->lock, flags);
-
-       return 0;
-}
+static DEFINE_PER_CPU(int, wakeup_nest);
 
 static void ep_poll_safewake(wait_queue_head_t *wq)
 {
-       int this_cpu = get_cpu();
-
-       ep_call_nested(&poll_safewake_ncalls,
-                      ep_poll_wakeup_proc, NULL, wq, (void *) (long) this_cpu);
+       unsigned long flags;
+       int subclass;
 
-       put_cpu();
+       local_irq_save(flags);
+       preempt_disable();
+       subclass = __this_cpu_read(wakeup_nest);
+       spin_lock_nested(&wq->lock, subclass + 1);
+       __this_cpu_inc(wakeup_nest);
+       wake_up_locked_poll(wq, POLLIN);
+       __this_cpu_dec(wakeup_nest);
+       spin_unlock(&wq->lock);
+       local_irq_restore(flags);
+       preempt_enable();
 }
 
 #else
@@ -671,7 +666,6 @@ static __poll_t ep_scan_ready_list(struct eventpoll *ep,
                              void *priv, int depth, bool ep_locked)
 {
        __poll_t res;
-       int pwake = 0;
        struct epitem *epi, *nepi;
        LIST_HEAD(txlist);
 
@@ -738,26 +732,11 @@ static __poll_t ep_scan_ready_list(struct eventpoll *ep,
         */
        list_splice(&txlist, &ep->rdllist);
        __pm_relax(ep->ws);
-
-       if (!list_empty(&ep->rdllist)) {
-               /*
-                * Wake up (if active) both the eventpoll wait list and
-                * the ->poll() wait list (delayed after we release the lock).
-                */
-               if (waitqueue_active(&ep->wq))
-                       wake_up(&ep->wq);
-               if (waitqueue_active(&ep->poll_wait))
-                       pwake++;
-       }
        write_unlock_irq(&ep->lock);
 
        if (!ep_locked)
                mutex_unlock(&ep->mtx);
 
-       /* We have to call this outside the lock */
-       if (pwake)
-               ep_poll_safewake(&ep->poll_wait);
-
        return res;
 }
 
@@ -2370,11 +2349,6 @@ static int __init eventpoll_init(void)
         */
        ep_nested_calls_init(&poll_loop_ncalls);
 
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-       /* Initialize the structure used to perform safe poll wait head wake ups */
-       ep_nested_calls_init(&poll_safewake_ncalls);
-#endif
-
        /*
         * We can have many thousands of epitems, so prevent this from
         * using an extra cache line on 64-bit (and smaller) CPUs