| From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 24/55] rcu: Not necessary to pass rcu_read_lock_held() to rcu_dereference_protected() | Date | Tue, 6 Sep 2011 11:00:18 -0700 |
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From: Michal Hocko <mhocko@suse.cz>
Since ca5ecddf (rcu: define __rcu address space modifier for sparse) rcu_dereference_check() use rcu_read_lock_held() as a part of condition automatically. Therefore, callers of rcu_dereference_check() no longer need to pass rcu_read_lock_held() to rcu_dereference_check().
Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> --- Documentation/RCU/lockdep.txt | 10 ++++------ 1 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/Documentation/RCU/lockdep.txt b/Documentation/RCU/lockdep.txt index d7a49b2..4998c63 100644 --- a/Documentation/RCU/lockdep.txt +++ b/Documentation/RCU/lockdep.txt @@ -48,13 +48,11 @@ checking of rcu_dereference() primitives: value of the pointer itself, for example, against NULL. The rcu_dereference_check() check expression can be any boolean -expression, but would normally include one of the rcu_read_lock_held() -family of functions and a lockdep expression. However, any boolean -expression can be used. For a moderately ornate example, consider -the following: +expression, but would normally include a lockdep expression. However, +any boolean expression can be used. For a moderately ornate example, +consider the following: file = rcu_dereference_check(fdt->fd[fd], - rcu_read_lock_held() || lockdep_is_held(&files->file_lock) || atomic_read(&files->count) == 1); @@ -62,7 +60,7 @@ This expression picks up the pointer "fdt->fd[fd]" in an RCU-safe manner, and, if CONFIG_PROVE_RCU is configured, verifies that this expression is used in: -1. An RCU read-side critical section, or +1. An RCU read-side critical section (implicit), or 2. with files->file_lock held, or 3. on an unshared files_struct. -- 1.7.3.2
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