From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Lai Jiangshan <laijs@cn.fujitsu.com>,
Jason Low <jason.low2@hp.com>, Brad Mouring <bmouring@ni.com>
Subject: [patch V3 4/7] rtmutex: Siplify remove_waiter()
Date: Mon, 09 Jun 2014 20:28:08 -0000 [thread overview]
Message-ID: <20140609202336.248536613@linutronix.de> (raw)
In-Reply-To: 20140609201118.387571774@linutronix.de
[-- Attachment #1: rtmutex-simplify-deboost.patch --]
[-- Type: text/plain, Size: 1843 bytes --]
Exit right away, when the removed waiter was not the top prioriy
waiter on the lock. Get rid of the extra indent level.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
kernel/locking/rtmutex.c | 26 ++++++++++----------------
1 file changed, 10 insertions(+), 16 deletions(-)
Index: tip/kernel/locking/rtmutex.c
===================================================================
--- tip.orig/kernel/locking/rtmutex.c
+++ tip/kernel/locking/rtmutex.c
@@ -780,7 +780,7 @@ static void remove_waiter(struct rt_mute
{
int first = (waiter == rt_mutex_top_waiter(lock));
struct task_struct *owner = rt_mutex_owner(lock);
- struct rt_mutex *next_lock = NULL;
+ struct rt_mutex *next_lock;
unsigned long flags;
raw_spin_lock_irqsave(¤t->pi_lock, flags);
@@ -788,28 +788,22 @@ static void remove_waiter(struct rt_mute
current->pi_blocked_on = NULL;
raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
- if (!owner)
+ if (!owner || !first)
return;
- if (first) {
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
- raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ rt_mutex_dequeue_pi(owner, waiter);
- rt_mutex_dequeue_pi(owner, waiter);
+ if (rt_mutex_has_waiters(lock))
+ rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock));
- if (rt_mutex_has_waiters(lock)) {
- struct rt_mutex_waiter *next;
+ __rt_mutex_adjust_prio(owner);
- next = rt_mutex_top_waiter(lock);
- rt_mutex_enqueue_pi(owner, next);
- }
- __rt_mutex_adjust_prio(owner);
+ /* Store the lock on which owner is blocked or NULL */
+ next_lock = task_blocked_on_lock(owner);
- /* Store the lock on which owner is blocked or NULL */
- next_lock = task_blocked_on_lock(owner);
-
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
- }
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
if (!next_lock)
return;
next prev parent reply other threads:[~2014-06-09 20:28 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-09 20:28 [patch V3 0/7] rtmutex: Code clarification and optimization Thomas Gleixner
2014-06-09 20:28 ` [patch V3 1/7] rtmutex: Deobfuscate chain walk Thomas Gleixner
2014-06-09 20:59 ` Steven Rostedt
2014-06-10 3:52 ` Lai Jiangshan
2014-06-10 3:21 ` Jason Low
2014-06-10 13:57 ` Brad Mouring
2014-06-09 20:28 ` [patch V3 2/7] rtmutex: Clarify the boost/deboost part Thomas Gleixner
2014-06-10 0:37 ` Steven Rostedt
2014-06-10 3:22 ` Jason Low
2014-06-10 14:04 ` Brad Mouring
2014-06-09 20:28 ` Thomas Gleixner [this message]
2014-06-10 0:53 ` [patch V3 4/7] rtmutex: Siplify remove_waiter() Steven Rostedt
2014-06-10 3:35 ` Lai Jiangshan
2014-06-10 3:44 ` Jason Low
2014-06-10 14:10 ` Brad Mouring
2014-06-09 20:28 ` [patch V3 3/7] rtmutex: Document pi chain walk Thomas Gleixner
2014-06-10 0:45 ` Steven Rostedt
2014-06-10 3:51 ` Lai Jiangshan
2014-06-10 14:21 ` Brad Mouring
2014-06-09 20:28 ` [patch V3 5/7] rtmutex: Confine deadlock logic to futex Thomas Gleixner
2014-06-10 0:59 ` Steven Rostedt
2014-06-10 4:03 ` Lai Jiangshan
2014-06-10 17:39 ` Thomas Gleixner
2014-06-09 20:28 ` [patch V3 7/7] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk Thomas Gleixner
2014-06-10 1:20 ` Steven Rostedt
2014-06-10 3:48 ` Jason Low
2014-06-10 17:41 ` Thomas Gleixner
2014-06-10 17:47 ` Steven Rostedt
2014-06-10 20:45 ` Thomas Gleixner
2014-06-10 14:57 ` Brad Mouring
2014-06-10 15:19 ` Steven Rostedt
2014-06-10 17:43 ` Thomas Gleixner
2014-06-10 17:51 ` Steven Rostedt
2014-06-10 20:46 ` Thomas Gleixner
2014-06-09 20:28 ` [patch V3 6/7] rtmutex: Cleanup deadlock detector debug logic Thomas Gleixner
2014-06-10 1:04 ` Steven Rostedt
2014-06-10 15:09 ` Brad Mouring
2014-06-10 0:27 ` [patch V3 0/7] rtmutex: Code clarification and optimization Steven Rostedt
2014-06-10 0:35 ` Steven Rostedt
2014-06-10 3:00 ` Lai Jiangshan
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