patch "binder: Use wake up hint for synchronous transactions." added to char-misc-next

This is a note to let you know that I've just added the patch titled

binder: Use wake up hint for synchronous transactions.

to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will also be merged in the next major kernel release during the merge window.

If you have any questions about this process, please let me know.

From: Riley Andrews <[email protected]>
Date: Thu, 29 Jun 2017 12:01:37 -0700
Subject: binder: Use wake up hint for synchronous transactions.

Use wake_up_interruptible_sync() to hint to the scheduler binder transactions are synchronous wakeups. Disable preemption while waking to avoid ping-ponging on the binder lock.

---
 drivers/android/binder.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

index 9393924ae8e8..f7665c31feca 100644
@@ -2200,8 +2200,12 @@ static void binder_transaction(struct binder_proc *proc,
 	list_add_tail(&t->work.entry, target_list);
 	tcomplete->type = BINDER_WORK_TRANSACTION_COMPLETE;
 	list_add_tail(&tcomplete->entry, &thread->todo);
-	if (target_wait)
-		wake_up_interruptible(target_wait);
+	if (target_wait) {
+		if (reply || !(t->flags & TF_ONE_WAY))
+			wake_up_interruptible_sync(target_wait);
+		else
+			wake_up_interruptible(target_wait);
+	}
 	return;
 
 err_translate_failed:

2.13.3