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

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-linus 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 hopefully also be merged in Linus's tree for the next -rc kernel release.

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