From: Riley Andrews <riandrews@google.com>
Date: Tue, 1 Sep 2015 19:42:07 +0000 (-0700)
Subject: FROMLIST: binder: Use wake up hint for synchronous transactions.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b5968811a7c6aeada9d8ff7a2b84b56020088c8c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

FROMLIST: binder: Use wake up hint for synchronous transactions.

(from https://patchwork.kernel.org/patch/9817747)

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.

Change-Id: I041dd798f3d0c4c15aa461e4e6d71dc270e1ca86
Signed-off-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Omprakash Dhyade <odhyade@codeaurora.org>
---

diff --git a/drivers/android/binder.c b/drivers/android/binder.c
index 9105f416ce46..9ff1d15f7c31 100644
--- a/drivers/android/binder.c
+++ b/drivers/android/binder.c
@@ -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: