From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759186AbcLCB3u (ORCPT ); Fri, 2 Dec 2016 20:29:50 -0500 Received: from hqemgate16.nvidia.com ([216.228.121.65]:19502 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbcLCB3t (ORCPT ); Fri, 2 Dec 2016 20:29:49 -0500 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Fri, 02 Dec 2016 05:27:52 -0800 Date: Fri, 2 Dec 2016 17:29:46 -0800 From: Andy Ritger To: Alex Goins CC: , , Subject: Re: include/linux/rtmutex.h: NOOP rt_mutex_destroy if !CONFIG_DEBUG_RT_MUTEXES Message-ID: <20161203012946.GN10827@prokofiev.nvidia.com> References: <1477447431-22813-1-git-send-email-agoins@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1477447431-22813-1-git-send-email-agoins@nvidia.com> X-NVConfidentiality: public User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This seems consistent with the spirit of DEBUG_MUTEX in non-RT kernels, so hopefully this is acceptable to the RT maintainers. Reviewed-by: Andy Ritger Thanks, - Andy On Tue, Oct 25, 2016 at 07:03:51PM -0700, Alex Goins wrote: > mutex_destroy is no-op inline when DEBUG_MUTEX is not enabled. When > mutex_destroy is indirectly used by non-GPL kernel modules that use inline > functions such as reservation_object_fini(), users can use a kernel with > DEBUG_MUTEX disabled to avoid a dependence on the GPL-only symbol > mutex_destroy. > > The RT Linux patches replace mutex_destroy with rt_mutex_destroy. > Currently, rt_mutex_destroy is GPL_ONLY irrespective of whether mutex > debugging is enabled. > > This patch aligns rt_mutex_destroy with mutex_destroy by using the same > no-op inline technique. This allows non-GPL modules to access the same > functionality with RT Linux as with regular Linux. > > Signed-off-by: Alex Goins > --- > include/linux/rtmutex.h | 7 ++++++- > kernel/locking/rtmutex.c | 5 ++--- > 2 files changed, 8 insertions(+), 4 deletions(-) > > diff --git a/include/linux/rtmutex.h b/include/linux/rtmutex.h > index 1abba5c..741e844 100644 > --- a/include/linux/rtmutex.h > +++ b/include/linux/rtmutex.h > @@ -56,6 +56,12 @@ struct hrtimer_sleeper; > #endif > > #ifdef CONFIG_DEBUG_RT_MUTEXES > + extern void rt_mutex_destroy(struct rt_mutex *lock); > +#else > + static inline void rt_mutex_destroy(struct rt_mutex *lock) {} > +#endif > + > +#ifdef CONFIG_DEBUG_RT_MUTEXES > # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ > , .name = #mutexname, .file = __FILE__, .line = __LINE__ > # define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__) > @@ -87,7 +93,6 @@ static inline int rt_mutex_is_locked(struct rt_mutex *lock) > } > > extern void __rt_mutex_init(struct rt_mutex *lock, const char *name); > -extern void rt_mutex_destroy(struct rt_mutex *lock); > > extern void rt_mutex_lock(struct rt_mutex *lock); > extern int rt_mutex_lock_interruptible(struct rt_mutex *lock); > diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c > index 1ec0f48..8d3a80e 100644 > --- a/kernel/locking/rtmutex.c > +++ b/kernel/locking/rtmutex.c > @@ -1513,6 +1513,7 @@ bool __sched rt_mutex_futex_unlock(struct rt_mutex *lock, > return rt_mutex_slowunlock(lock, wqh); > } > > +#ifdef CONFIG_DEBUG_RT_MUTEXES > /** > * rt_mutex_destroy - mark a mutex unusable > * @lock: the mutex to be destroyed > @@ -1524,12 +1525,10 @@ bool __sched rt_mutex_futex_unlock(struct rt_mutex *lock, > void rt_mutex_destroy(struct rt_mutex *lock) > { > WARN_ON(rt_mutex_is_locked(lock)); > -#ifdef CONFIG_DEBUG_RT_MUTEXES > lock->magic = NULL; > -#endif > } > - > EXPORT_SYMBOL_GPL(rt_mutex_destroy); > +#endif > > /** > * __rt_mutex_init - initialize the rt lock