Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754595AbaFJDoQ (ORCPT ); Mon, 9 Jun 2014 23:44:16 -0400 Received: from mail-ig0-f182.google.com ([209.85.213.182]:54154 "EHLO mail-ig0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754414AbaFJDoP (ORCPT ); Mon, 9 Jun 2014 23:44:15 -0400 MIME-Version: 1.0 In-Reply-To: <20140609205329.52b8c0d5@gandalf.local.home> References: <20140609201118.387571774@linutronix.de> <20140609202336.248536613@linutronix.de> <20140609205329.52b8c0d5@gandalf.local.home> Date: Mon, 9 Jun 2014 20:44:15 -0700 X-Google-Sender-Auth: 1QgQAdFh9A5DA0GEl4N9ThPwtBY Message-ID: Subject: Re: [patch V3 4/7] rtmutex: Siplify remove_waiter() From: Jason Low To: Steven Rostedt Cc: Thomas Gleixner , LKML , Peter Zijlstra , Ingo Molnar , Lai Jiangshan , Jason Low , Brad Mouring Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 9, 2014 at 5:53 PM, Steven Rostedt wrote: > On Mon, 09 Jun 2014 20:28:08 -0000 > Thomas Gleixner wrote: > >> 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 >> --- >> 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); >> > > Add comment here, something like... > > /* > * Only update priority if this task was the highest priority > * task waiting on the lock, and there is an owner to update. > */ Would it also make it clearer if we were to change "first" to something such as "bool is_top_waiter"? > Rest looks good. > > Reviewed-by: Steven Rostedt Reviewed-by: Jason Low > -- Steve > > >> - 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/