[RFC][RT][PATCH 2/4] rtmutex: Try to take lock early in rt_spin_lock_slowlock()

[Steven Rostedt <rostedt@goodmis.org>]

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From: Steven Rostedt <srostedt@redhat.com>

Try to take the lock again as soon as we go into the
rt_spin_lock_slowlock() code before doing the setup and wait loop.
This makes the code closer to what the rt_mutex_slowlock() does,
which will help in simplifying this code in later commits.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
---
 kernel/rtmutex.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index f0ce334..318d7ed 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -829,6 +829,11 @@ rt_spin_lock_slowlock(struct rt_mutex *lock)
 	raw_spin_lock_irqsave(&lock->wait_lock, flags);
 	init_lists(lock);
 
+	if (do_try_to_take_rt_mutex(lock, STEAL_LATERAL)) {
+		raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+		return;
+	}
+
 	BUG_ON(rt_mutex_owner(lock) == current);
 
 	/*
-- 
1.7.2.3