From da2f34d35fd8ad11a8db9b7ab3b387fe7ec2e709 Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <dbueso@suse.de>
Date: Tue, 24 Mar 2020 11:23:30 -0700
Subject: [PATCH] rcuwait: Let rcuwait_wake_up() return whether or not a task was awoken
References: bsc#1167594
Patch-mainline: Submitted - 2020-03-23, may be unacceptable for upstream

Propagating the return value of wake_up_process() back to the caller
can come in handy for future users, such as for statistics or
accounting purposes.

Link: https://lore.kernel.org/lkml/20200324044453.15733-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 include/linux/rcuwait.h |    2 +-
 kernel/exit.c           |    7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

--- a/include/linux/rcuwait.h
+++ b/include/linux/rcuwait.h
@@ -24,7 +24,7 @@ static inline void rcuwait_init(struct r
 	w->task = NULL;
 }
 
-extern void rcuwait_wake_up(struct rcuwait *w);
+extern int rcuwait_wake_up(struct rcuwait *w);
 
 /*
  * The caller is responsible for locking around rcuwait_wait_event(),
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -234,8 +234,9 @@ repeat:
 		goto repeat;
 }
 
-void rcuwait_wake_up(struct rcuwait *w)
+int rcuwait_wake_up(struct rcuwait *w)
 {
+	int ret = 0;
 	struct task_struct *task;
 
 	rcu_read_lock();
@@ -255,8 +256,10 @@ void rcuwait_wake_up(struct rcuwait *w)
 
 	task = rcu_dereference(w->task);
 	if (task)
-		wake_up_process(task);
+		ret = wake_up_process(task);
 	rcu_read_unlock();
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(rcuwait_wake_up);