[PATCH] locks should not be needed for reading completion state

[Nicholas Mc Guire]

Signed-off-by: Nicholas Mc Guire 
---

Should that not be enough to wrap it into ACCESS_ONCE() here ?

Not a wild performance benefit - but might be worth it anyway

 kernel/sched/completion.c |9 +
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 607f852..7c5cd70 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -288,13 +288,6 @@ EXPORT_SYMBOL(try_wait_for_completion);
  */
 bool completion_done(struct completion *x)
 {
-   unsigned long flags;
-   int ret = 1;
-
-   spin_lock_irqsave(>wait.lock, flags);
-   if (!x->done)
-   ret = 0;
-   spin_unlock_irqrestore(>wait.lock, flags);
-   return ret;
+   return !ACCESS_ONCE(x->done);
 }
 EXPORT_SYMBOL(completion_done);
-- 
1.7.10.4

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[PATCH] locks should not be needed for reading completion state

[Nicholas Mc Guire]

Signed-off-by: Nicholas Mc Guire der.h...@hofr.at
---

Should that not be enough to wrap it into ACCESS_ONCE() here ?

Not a wild performance benefit - but might be worth it anyway

 kernel/sched/completion.c |9 +
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/kernel/sched/completion.c b/kernel/sched/completion.c
index 607f852..7c5cd70 100644
--- a/kernel/sched/completion.c
+++ b/kernel/sched/completion.c
@@ -288,13 +288,6 @@ EXPORT_SYMBOL(try_wait_for_completion);
  */
 bool completion_done(struct completion *x)
 {
-   unsigned long flags;
-   int ret = 1;
-
-   spin_lock_irqsave(x-wait.lock, flags);
-   if (!x-done)
-   ret = 0;
-   spin_unlock_irqrestore(x-wait.lock, flags);
-   return ret;
+   return !ACCESS_ONCE(x-done);
 }
 EXPORT_SYMBOL(completion_done);
-- 
1.7.10.4

--
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