From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030291AbbCMPcr (ORCPT ); Fri, 13 Mar 2015 11:32:47 -0400 Received: from smtprelay0013.hostedemail.com ([216.40.44.13]:44363 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752324AbbCMPPS (ORCPT ); Fri, 13 Mar 2015 11:15:18 -0400 X-Session-Marker: 6E657665747340676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,,::::::::::::::::,RULES_HIT:355:379:871:988:989:1183:1260:1277:1312:1313:1314:1345:1516:1518:1519:1522:1534:1593:1594:1595:1596:1692:1730:1747:1777:1792:2392:2393:2559:2562:2828:3138:3139:3140:3141:3142:3876:3877:5007:6114:6261:6642:6748:7281:7901:10004:10848:11604:11914:12517:12519:13895:14394:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: rub28_684bdab49f560 X-Filterd-Recvd-Size: 3819 Message-Id: <20150313151516.157818183@goodmis.org> User-Agent: quilt/0.61-1 Date: Fri, 13 Mar 2015 11:15:02 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Lai Jiangshan Subject: [PATCH RT 08/31] rtmutex: Simplify remove_waiter() References: <20150313151454.809081378@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0008-rtmutex-Simplify-remove_waiter.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10.70-rt75-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner upstream commit: 1ca7b86062ec8473d03c5cdfd336abc8b1c8098c Exit right away, when the removed waiter was not the top priority waiter on the lock. Get rid of the extra indent level. Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Lai Jiangshan Signed-off-by: Steven Rostedt Conflicts: kernel/rtmutex.c --- kernel/rtmutex.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/kernel/rtmutex.c b/kernel/rtmutex.c index b6c48cb7f337..823f782b1847 100644 --- a/kernel/rtmutex.c +++ b/kernel/rtmutex.c @@ -898,7 +898,7 @@ static void wakeup_next_waiter(struct rt_mutex *lock) static void remove_waiter(struct rt_mutex *lock, struct rt_mutex_waiter *waiter) { - int first = (waiter == rt_mutex_top_waiter(lock)); + bool is_top_waiter = (waiter == rt_mutex_top_waiter(lock)); struct task_struct *owner = rt_mutex_owner(lock); struct rt_mutex *next_lock = NULL; unsigned long flags; @@ -908,31 +908,34 @@ static void remove_waiter(struct rt_mutex *lock, current->pi_blocked_on = NULL; raw_spin_unlock_irqrestore(¤t->pi_lock, flags); - if (!owner) + /* + * Only update priority if the waiter was the highest priority + * waiter of the lock and there is an owner to update. + */ + if (!owner || !is_top_waiter) 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)) { - struct rt_mutex_waiter *next; + if (rt_mutex_has_waiters(lock)) + rt_mutex_enqueue_pi(owner, rt_mutex_top_waiter(lock)); - next = rt_mutex_top_waiter(lock); - rt_mutex_enqueue_pi(owner, next); - } - __rt_mutex_adjust_prio(owner); + __rt_mutex_adjust_prio(owner); - /* Store the lock on which owner is blocked or NULL */ + /* Store the lock on which owner is blocked or NULL */ + if (rt_mutex_real_waiter(owner->pi_blocked_on)) next_lock = task_blocked_on_lock(owner); - raw_spin_unlock_irqrestore(&owner->pi_lock, flags); - } + raw_spin_unlock_irqrestore(&owner->pi_lock, flags); WARN_ON(!plist_node_empty(&waiter->pi_list_entry)); + /* + * Don't walk the chain, if the owner task is not blocked + * itself. + */ if (!next_lock) return; -- 2.1.4