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rcu: Not necessary to pass rcu_read_lock_held() to rcu_dereference_protected() 

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>
This commit is contained in:
Michal Hocko 2011-07-08 08:48:24 -07:00 committed by Paul E. McKenney
parent e4cc1f22b2
commit e5177ec77d
1 changed files with 4 additions and 6 deletions
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10
Documentation/RCU/lockdep.txt
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@ -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.