From 3120438ad68601f341e61e7cb1323b0e1a6ca367 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 22 Feb 2010 17:04:48 -0800 Subject: [PATCH] rcu: Disable lockdep checking in RCU list-traversal primitives 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 Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1266887105-1528-4-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar --- 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 1bf0f708c4fc..779d70749beb 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)) /** * list_for_each_entry_continue_rcu - continue iteration over list of given type @@ -418,10 +418,10 @@ 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 589a40919f01..b70ffe53cb9f 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 -- GitLab