From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933500Ab2JLBWQ (ORCPT ); Thu, 11 Oct 2012 21:22:16 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:21152 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753258Ab2JLBV2 (ORCPT ); Thu, 11 Oct 2012 21:21:28 -0400 X-Authority-Analysis: v=2.0 cv=dvhZ+ic4 c=1 sm=0 a=rXTBtCOcEpjy1lPqhTCpEQ==:17 a=mNMOxpOpBa8A:10 a=Ciwy3NGCPMMA:10 a=QR-o9JM4IVQA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=oHo0cinKwKoA:10 a=VwQbUJbxAAAA:8 a=00CX1lbMB8ObnoKVni4A:9 a=Zh68SRI7RUMA:10 a=jeBq3FmKZ4MA:10 a=rXTBtCOcEpjy1lPqhTCpEQ==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.115.198 Message-Id: <20121012012126.374055723@goodmis.org> User-Agent: quilt/0.60-1 Date: Thu, 11 Oct 2012 21:20:29 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , John Kacur Subject: [PATCH RT 5/8] rt: rwsem/rwlock: lockdep annotations References: <20121012012024.056658930@goodmis.org> Content-Disposition: inline; filename=0005-rt-rwsem-rwlock-lockdep-annotations.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner rwlocks and rwsems on RT do not allow multiple readers. Annotate the lockdep acquire functions accordingly. Signed-off-by: Thomas Gleixner Cc: stable-rt@vger.kernel.org Signed-off-by: Steven Rostedt --- kernel/rt.c | 46 +++++++++++++++++++++++++--------------------- 1 file changed, 25 insertions(+), 21 deletions(-) diff --git a/kernel/rt.c b/kernel/rt.c index 092d6b3..aa10504 100644 --- a/kernel/rt.c +++ b/kernel/rt.c @@ -216,15 +216,17 @@ int __lockfunc rt_read_trylock(rwlock_t *rwlock) * write locked. */ migrate_disable(); - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { ret = rt_mutex_trylock(lock); - else if (!rwlock->read_depth) + if (ret) + rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_); + } else if (!rwlock->read_depth) { ret = 0; + } - if (ret) { + if (ret) rwlock->read_depth++; - rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_); - } else + else migrate_enable(); return ret; @@ -242,13 +244,13 @@ void __lockfunc rt_read_lock(rwlock_t *rwlock) { struct rt_mutex *lock = &rwlock->lock; - rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_); - /* * recursive read locks succeed when current owns the lock */ - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { + rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_); __rt_spin_lock(lock); + } rwlock->read_depth++; } @@ -264,11 +266,11 @@ EXPORT_SYMBOL(rt_write_unlock); void __lockfunc rt_read_unlock(rwlock_t *rwlock) { - rwlock_release(&rwlock->dep_map, 1, _RET_IP_); - /* Release the lock only when read_depth is down to 0 */ - if (--rwlock->read_depth == 0) + if (--rwlock->read_depth == 0) { + rwlock_release(&rwlock->dep_map, 1, _RET_IP_); __rt_spin_unlock(&rwlock->lock); + } } EXPORT_SYMBOL(rt_read_unlock); @@ -315,9 +317,10 @@ EXPORT_SYMBOL(rt_up_write); void rt_up_read(struct rw_semaphore *rwsem) { - rwsem_release(&rwsem->dep_map, 1, _RET_IP_); - if (--rwsem->read_depth == 0) + if (--rwsem->read_depth == 0) { + rwsem_release(&rwsem->dep_map, 1, _RET_IP_); rt_mutex_unlock(&rwsem->lock); + } } EXPORT_SYMBOL(rt_up_read); @@ -366,15 +369,16 @@ int rt_down_read_trylock(struct rw_semaphore *rwsem) * but not when read_depth == 0 which means that the rwsem is * write locked. */ - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { ret = rt_mutex_trylock(&rwsem->lock); - else if (!rwsem->read_depth) + if (ret) + rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_); + } else if (!rwsem->read_depth) { ret = 0; + } - if (ret) { + if (ret) rwsem->read_depth++; - rwsem_acquire(&rwsem->dep_map, 0, 1, _RET_IP_); - } return ret; } EXPORT_SYMBOL(rt_down_read_trylock); @@ -383,10 +387,10 @@ static void __rt_down_read(struct rw_semaphore *rwsem, int subclass) { struct rt_mutex *lock = &rwsem->lock; - rwsem_acquire_read(&rwsem->dep_map, subclass, 0, _RET_IP_); - - if (rt_mutex_owner(lock) != current) + if (rt_mutex_owner(lock) != current) { + rwsem_acquire(&rwsem->dep_map, subclass, 0, _RET_IP_); rt_mutex_lock(&rwsem->lock); + } rwsem->read_depth++; } -- 1.7.10.4