[PATCH 2/4] rcuwait: Let rcuwait_wake_up() return whether or not a task was awoken

From: Davidlohr Bueso <dave@stgolabs.net>
To: tglx@linutronix.de, pbonzini@redhat.com
Cc: bigeasy@linutronix.de, peterz@infradead.org, rostedt@goodmis.org,
	torvalds@linux-foundation.org, will@kernel.org,
	joel@joelfernandes.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, dave@stgolabs.net,
	Davidlohr Bueso <dbueso@suse.de>
Subject: [PATCH 2/4] rcuwait: Let rcuwait_wake_up() return whether or not a task was awoken
Date: Mon, 23 Mar 2020 21:44:51 -0700	[thread overview]
Message-ID: <20200324044453.15733-3-dave@stgolabs.net> (raw)
In-Reply-To: <20200324044453.15733-1-dave@stgolabs.net>

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.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
---
 include/linux/rcuwait.h | 2 +-
 kernel/exit.c           | 7 +++++--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h
index 2ffe1ee6d482..6ebb23258a27 100644
--- a/include/linux/rcuwait.h
+++ b/include/linux/rcuwait.h
@@ -25,7 +25,7 @@ static inline void rcuwait_init(struct rcuwait *w)
 	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(),
diff --git a/kernel/exit.c b/kernel/exit.c
index a33c0baffdae..dbddc9d83407 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -225,8 +225,9 @@ void release_task(struct task_struct *p)
 		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();
@@ -246,8 +247,10 @@ 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);
 
-- 
2.16.4

