From: Thomas Gleixner <t...@linutronix.de>

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

Signed-off-by: Thomas Gleixner <t...@linutronix.de>
[PG: carry forward from v3.10-rt, drop RT specific chunks, align with
 names that were chosen to match normal waitqueue support.]
Signed-off-by: Paul Gortmaker <paul.gortma...@windriver.com>
---
 include/linux/completion.h |  8 ++++----
 include/linux/uprobes.h    |  1 +
 kernel/sched/completion.c  | 34 +++++++++++++++++-----------------
 3 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/include/linux/completion.h b/include/linux/completion.h
index 5d5aaae..d8e6db9 100644
--- a/include/linux/completion.h
+++ b/include/linux/completion.h
@@ -8,7 +8,7 @@
  * See kernel/sched/completion.c for details.
  */
 
-#include <linux/wait.h>
+#include <linux/swait.h>
 
 /*
  * struct completion - structure used to maintain state for a "completion"
@@ -24,11 +24,11 @@
  */
 struct completion {
        unsigned int done;
-       wait_queue_head_t wait;
+       swait_queue_head_t wait;
 };
 
 #define COMPLETION_INITIALIZER(work) \
-       { 0, __WAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
+       { 0, SWAIT_QUEUE_HEAD_INITIALIZER((work).wait) }
 
 #define COMPLETION_INITIALIZER_ONSTACK(work) \
        ({ init_completion(&work); work; })
@@ -73,7 +73,7 @@ struct completion {
 static inline void init_completion(struct completion *x)
 {
        x->done = 0;
-       init_waitqueue_head(&x->wait);
+       init_swaitqueue_head(&x->wait);
 }
 
 /**
diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
index 319eae7..e3a167f 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -26,6 +26,7 @@
 
 #include <linux/errno.h>
 #include <linux/rbtree.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 a63f4dc..bcdd609 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);
+       __swake_up_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);
+       __swake_up_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;
 }
 
@@ -267,12 +267,12 @@ bool try_wait_for_completion(struct completion *x)
        unsigned long flags;
        int ret = 1;
 
-       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);
@@ -290,10 +290,10 @@ bool completion_done(struct completion *x)
        unsigned long flags;
        int ret = 1;
 
-       spin_lock_irqsave(&x->wait.lock, flags);
+       raw_spin_lock_irqsave(&x->wait.lock, flags);
        if (!x->done)
                ret = 0;
-       spin_unlock_irqrestore(&x->wait.lock, flags);
+       raw_spin_unlock_irqrestore(&x->wait.lock, flags);
        return ret;
 }
 EXPORT_SYMBOL(completion_done);
-- 
1.8.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to