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From: Gregory Haskins <ghaskins@novell.com>
To: mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de,
	rostedt@goodmis.org, linux-rt-users@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, bill.huey@gmail.com,
	kevin@hilman.org, cminyard@mvista.com, dsingleton@mvista.com,
	dwalker@mvista.com, npiggin@suse.de, dsaxena@plexity.net,
	ak@suse.de, pavel@ucw.cz, acme@redhat.com, gregkh@suse.de,
	sdietrich@novell.com, pmorreale@novell.com, mkohari@novell.com,
	ghaskins@novell.com
Subject: [(RT RFC) PATCH v2 9/9] remove the extra call to try_to_take_lock
Date: Mon, 25 Feb 2008 11:01:23 -0500	[thread overview]
Message-ID: <20080225160123.11268.6904.stgit@novell1.haskins.net> (raw)
In-Reply-To: <20080225155959.11268.35541.stgit@novell1.haskins.net>

From: Peter W. Morreale <pmorreale@novell.com>

Remove the redundant attempt to get the lock.  While it is true that the
exit path with this patch adds an un-necessary xchg (in the event the
lock is granted without further traversal in the loop) experimentation
shows that we almost never encounter this situation. 

Signed-off-by: Peter W. Morreale <pmorreale@novell.com>
---

 kernel/rtmutex.c |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c
index b81bbef..266ae31 100644
--- a/kernel/rtmutex.c
+++ b/kernel/rtmutex.c
@@ -756,12 +756,6 @@ rt_spin_lock_slowlock(struct rt_mutex *lock)
 	spin_lock_irqsave(&lock->wait_lock, flags);
 	init_lists(lock);
 
-	/* Try to acquire the lock again: */
-	if (try_to_take_rt_mutex(lock)) {
-		spin_unlock_irqrestore(&lock->wait_lock, flags);
-		return;
-	}
-
 	BUG_ON(rt_mutex_owner(lock) == current);
 
 	/*


      parent reply	other threads:[~2008-02-25 16:32 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-02-25 16:00 [(RT RFC) PATCH v2 0/9] adaptive real-time locks Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing to include lateral priority Gregory Haskins
2008-03-03 15:13   ` Steven Rostedt
2008-03-03 15:41     ` [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing to includelateral priority Gregory Haskins
2008-03-03 15:55       ` Steven Rostedt
2008-03-03 15:55         ` [(RT RFC) PATCH v2 1/9] allow rt-mutex lock-stealing toincludelateral priority Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 2/9] sysctl for runtime-control of lateral mutex stealing Gregory Haskins
2008-02-25 21:53   ` Pavel Machek
2008-02-25 22:57     ` Sven-Thorsten Dietrich
2008-02-25 23:00       ` Pavel Machek
2008-02-25 23:40         ` Sven-Thorsten Dietrich
2008-02-26  1:15       ` Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 3/9] rearrange rt_spin_lock sleep Gregory Haskins
2008-02-25 21:54   ` Pavel Machek
2008-02-26  0:45     ` Gregory Haskins
2008-02-25 16:00 ` [(RT RFC) PATCH v2 4/9] optimize rt lock wakeup Gregory Haskins
2008-03-03 15:37   ` Steven Rostedt
2008-03-03 15:41     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 5/9] adaptive real-time lock support Gregory Haskins
2008-02-25 22:03   ` Pavel Machek
2008-02-26  0:48     ` Gregory Haskins
2008-02-26 15:03     ` Gregory Haskins
2008-02-26 18:06       ` Pavel Machek
2008-02-26 18:01         ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 6/9] add a loop counter based timeout mechanism Gregory Haskins
2008-02-25 22:06   ` Pavel Machek
2008-02-25 22:19     ` Greg KH
2008-02-25 22:21       ` Pavel Machek
2008-02-25 22:39     ` Sven-Thorsten Dietrich
2008-02-26 15:09     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 7/9] adaptive mutexes Gregory Haskins
2008-02-25 22:09   ` Pavel Machek
2008-02-26  0:52     ` Gregory Haskins
2008-02-25 16:01 ` [(RT RFC) PATCH v2 8/9] adjust pi_lock usage in wakeup Gregory Haskins
2008-02-25 22:10   ` Pavel Machek
2008-02-25 16:01 ` Gregory Haskins [this message]

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