From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754295Ab0AECEU (ORCPT ); Mon, 4 Jan 2010 21:04:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754211Ab0AECER (ORCPT ); Mon, 4 Jan 2010 21:04:17 -0500 Received: from e4.ny.us.ibm.com ([32.97.182.144]:34957 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754194Ab0AECEO (ORCPT ); Mon, 4 Jan 2010 21:04:14 -0500 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: mingo@elte.hu, laijs@cn.fujitsu.com, dipankar@in.ibm.com, akpm@linux-foundation.org, mathieu.desnoyers@polymtl.ca, josh@joshtriplett.org, dvhltc@us.ibm.com, niv@us.ibm.com, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, Valdis.Kletnieks@vt.edu, dhowells@redhat.com, "Paul E. McKenney" Subject: [PATCH tip/core/rcu 3/8] rcu: disable lockdep checking in RCU list-traversal primitives Date: Mon, 4 Jan 2010 18:04:06 -0800 Message-Id: <12626570513455-git-send-email-> X-Mailer: git-send-email 1.5.2.5 In-Reply-To: <20100105020345.GA32114@linux.vnet.ibm.com> References: <20100105020345.GA32114@linux.vnet.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul E. McKenney The theory is that use of bare rcu_dereference() is more prone to error than use of the RCU list-traversal primitives. Therefore, disable lockdep RCU read-side critical-section checking in these primitives for the time being. Once all of the rcu_dereference() uses have been dealt with, it may be time to re-enable lockdep checking for the RCU list-traversal primitives. Signed-off-by: Paul E. McKenney --- include/linux/rculist.h | 14 +++++++------- include/linux/rculist_nulls.h | 4 ++-- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/include/linux/rculist.h b/include/linux/rculist.h index 5710f43..0d4b617 100644 --- a/include/linux/rculist.h +++ b/include/linux/rculist.h @@ -208,7 +208,7 @@ static inline void list_splice_init_rcu(struct list_head *list, * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock(). */ #define list_entry_rcu(ptr, type, member) \ - container_of(rcu_dereference(ptr), type, member) + container_of(rcu_dereference_raw(ptr), type, member) /** * list_first_entry_rcu - get the first element from a list @@ -225,9 +225,9 @@ static inline void list_splice_init_rcu(struct list_head *list, list_entry_rcu((ptr)->next, type, member) #define __list_for_each_rcu(pos, head) \ - for (pos = rcu_dereference((head)->next); \ + for (pos = rcu_dereference_raw((head)->next); \ pos != (head); \ - pos = rcu_dereference(pos->next)) + pos = rcu_dereference_raw(pos->next)) /** * list_for_each_entry_rcu - iterate over rcu list of given type @@ -257,9 +257,9 @@ static inline void list_splice_init_rcu(struct list_head *list, * as long as the traversal is guarded by rcu_read_lock(). */ #define list_for_each_continue_rcu(pos, head) \ - for ((pos) = rcu_dereference((pos)->next); \ + for ((pos) = rcu_dereference_raw((pos)->next); \ prefetch((pos)->next), (pos) != (head); \ - (pos) = rcu_dereference((pos)->next)) + (pos) = rcu_dereference_raw((pos)->next)) /** * hlist_del_rcu - deletes entry from hash list without re-initialization @@ -404,10 +404,10 @@ static inline void hlist_add_after_rcu(struct hlist_node *prev, * as long as the traversal is guarded by rcu_read_lock(). */ #define hlist_for_each_entry_rcu(tpos, pos, head, member) \ - for (pos = rcu_dereference((head)->first); \ + for (pos = rcu_dereference_raw((head)->first); \ pos && ({ prefetch(pos->next); 1; }) && \ ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; }); \ - pos = rcu_dereference(pos->next)) + pos = rcu_dereference_raw(pos->next)) #endif /* __KERNEL__ */ #endif diff --git a/include/linux/rculist_nulls.h b/include/linux/rculist_nulls.h index 589a409..b70ffe5 100644 --- a/include/linux/rculist_nulls.h +++ b/include/linux/rculist_nulls.h @@ -101,10 +101,10 @@ static inline void hlist_nulls_add_head_rcu(struct hlist_nulls_node *n, * */ #define hlist_nulls_for_each_entry_rcu(tpos, pos, head, member) \ - for (pos = rcu_dereference((head)->first); \ + for (pos = rcu_dereference_raw((head)->first); \ (!is_a_nulls(pos)) && \ ({ tpos = hlist_nulls_entry(pos, typeof(*tpos), member); 1; }); \ - pos = rcu_dereference(pos->next)) + pos = rcu_dereference_raw(pos->next)) #endif #endif -- 1.5.2.5