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

Davidlohr Bueso
2020-03-24T04:46:15Z

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