completion: Use simple wait queues

Completions have no long lasting callbacks and therefor do not need
the complex waitqueue variant. Use simple waitqueues which reduces the
contention on the waitqueue lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

7 files changed, 33 insertions, 27 deletions

diff --git a/drivers/net/wireless/orinoco/orinoco_usb.c b/drivers/net/wireless/orinoco/orinoco_usb.c
index f2cd513d54b2c2..6c0f4c9638a241 100644
--- a/drivers/net/wireless/orinoco/orinoco_usb.c
+++ b/drivers/net/wireless/orinoco/orinoco_usb.c
@@ -697,7 +697,7 @@ static void ezusb_req_ctx_wait(struct ezusb_priv *upriv,
 			while (!ctx->done.done && msecs--)
 				udelay(1000);
 		} else {
-			wait_event_interruptible(ctx->done.wait,
+			swait_event_interruptible(ctx->done.wait,
 						 ctx->done.done);
 		}
 		break;
diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index cf43e9e18368dc..3ba63db4dce785 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c
@@ -1405,7 +1405,7 @@ static void ffs_data_put(struct ffs_data *ffs)
 		pr_info("%s(): freeing\n", __func__);
 		ffs_data_clear(ffs);
 		BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
-		       waitqueue_active(&ffs->ep0req_completion.wait));
+		       swaitqueue_active(&ffs->ep0req_completion.wait));
 		kfree(ffs->dev_name);
 		kfree(ffs);
 	}
diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index f454c7af489ce0..b20a603436640e 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -345,7 +345,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
 	spin_unlock_irq (&epdata->dev->lock);
 
 	if (likely (value == 0)) {
-		value = wait_event_interruptible (done.wait, done.done);
+		value = swait_event_interruptible (done.wait, done.done);
 		if (value != 0) {
 			spin_lock_irq (&epdata->dev->lock);
 			if (likely (epdata->ep != NULL)) {
@@ -354,7 +354,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
 				usb_ep_dequeue (epdata->ep, epdata->req);
 				spin_unlock_irq (&epdata->dev->lock);
 
-				wait_event (done.wait, done.done);
+				swait_event (done.wait, done.done);
 				if (epdata->status == -ECONNRESET)
 					epdata->status = -EINTR;
 			} else {
diff --git a/include/linux/completion.h b/include/linux/completion.h
index 5d5aaae3af433f..3fe8d14c98c06b 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -7,8 +7,7 @@
  * Atomic wait-for-completion handler data structures.
  * See kernel/sched/completion.c for details.
  */
-
-#include <linux/wait.h>
+#include <linux/wait-simple.h>
 
 /*
  * struct completion - structure used to maintain state for a "completion"
@@ -24,11 +23,11 @@
  */
 struct completion {
 	unsigned int done;
-	wait_queue_head_t wait;
+	struct swait_head wait;
 };
 
 #define COMPLETION_INITIALIZER(work) \
-	{ 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+	{ 0, SWAIT_HEAD_INITIALIZER((work).wait) }
 
 #define COMPLETION_INITIALIZER_ONSTACK(work) \
 	({ init_completion(&work); work; })
@@ -73,7 +72,7 @@ struct completion {
 static inline void init_completion(struct completion *x)
 {
 	x->done = 0;
-	init_waitqueue_head(&x->wait);
+	init_swait_head(&x->wait);
 }
 
 /**
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 4a29c75b146e1c..0a294e950df840 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -27,6 +27,7 @@
 #include <linux/errno.h>
 #include <linux/rbtree.h>
 #include <linux/types.h>
+#include <linux/wait.h>
 
 struct vm_area_struct;
 struct mm_struct;
diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 8d0f35debf3565..45ebcffd9feb08 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -30,10 +30,10 @@ void complete(struct completion *x)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done++;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 1);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	__swait_wake_locked(&x->wait, TASK_NORMAL, 1);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete);
 
@@ -50,10 +50,10 @@ void complete_all(struct completion *x)
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	x->done += UINT_MAX/2;
-	__wake_up_locked(&x->wait, TASK_NORMAL, 0);
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	__swait_wake_locked(&x->wait, TASK_NORMAL, 0);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 }
 EXPORT_SYMBOL(complete_all);
 
@@ -62,20 +62,20 @@ do_wait_for_common(struct completion *x,
 		   long (*action)(long), long timeout, int state)
 {
 	if (!x->done) {
-		DECLARE_WAITQUEUE(wait, current);
+		DEFINE_SWAITER(wait);
 
-		__add_wait_queue_tail_exclusive(&x->wait, &wait);
+		swait_prepare_locked(&x->wait, &wait);
 		do {
 			if (signal_pending_state(state, current)) {
 				timeout = -ERESTARTSYS;
 				break;
 			}
 			__set_current_state(state);
-			spin_unlock_irq(&x->wait.lock);
+			raw_spin_unlock_irq(&x->wait.lock);
 			timeout = action(timeout);
-			spin_lock_irq(&x->wait.lock);
+			raw_spin_lock_irq(&x->wait.lock);
 		} while (!x->done && timeout);
-		__remove_wait_queue(&x->wait, &wait);
+		swait_finish_locked(&x->wait, &wait);
 		if (!x->done)
 			return timeout;
 	}
@@ -89,9 +89,9 @@ __wait_for_common(struct completion *x,
 {
 	might_sleep();
 
-	spin_lock_irq(&x->wait.lock);
+	raw_spin_lock_irq(&x->wait.lock);
 	timeout = do_wait_for_common(x, action, timeout, state);
-	spin_unlock_irq(&x->wait.lock);
+	raw_spin_unlock_irq(&x->wait.lock);
 	return timeout;
 }
 
@@ -277,12 +277,12 @@ bool try_wait_for_completion(struct completion *x)
 	if (!READ_ONCE(x->done))
 		return 0;
 
-	spin_lock_irqsave(&x->wait.lock, flags);
+	raw_spin_lock_irqsave(&x->wait.lock, flags);
 	if (!x->done)
 		ret = 0;
 	else
 		x->done--;
-	spin_unlock_irqrestore(&x->wait.lock, flags);
+	raw_spin_unlock_irqrestore(&x->wait.lock, flags);
 	return ret;
 }
 EXPORT_SYMBOL(try_wait_for_completion);
@@ -311,7 +311,7 @@ bool completion_done(struct completion *x)
 	 * after it's acquired the lock.
 	 */
 	smp_rmb();
-	spin_unlock_wait(&x->wait.lock);
+	raw_spin_unlock_wait(&x->wait.lock);
 	return true;
 }
 EXPORT_SYMBOL(completion_done);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8a824e155551c5..878db4d97d1d91 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3102,7 +3102,10 @@ void migrate_disable(void)
 	}
 
 #ifdef CONFIG_SCHED_DEBUG
-	WARN_ON_ONCE(p->migrate_disable_atomic);
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
 #endif
 
 	if (p->migrate_disable) {
@@ -3129,7 +3132,10 @@ void migrate_enable(void)
 	}
 
 #ifdef CONFIG_SCHED_DEBUG
-	WARN_ON_ONCE(p->migrate_disable_atomic);
+	if (unlikely(p->migrate_disable_atomic)) {
+		tracing_off();
+		WARN_ON_ONCE(1);
+	}
 #endif
 	WARN_ON_ONCE(p->migrate_disable <= 0);