rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods

It is illegal to wait for an SRCU grace period while within the
corresponding flavor of SRCU read-side critical section.  Therefore,
this commit updates the srcu_read_lock() docbook accordingly.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2010-08-16 10:50:54 -07:00
parent 5cc6517abd
commit 73d4da4d36

View File

@ -139,7 +139,12 @@ static inline int srcu_read_lock_held(struct srcu_struct *sp)
* @sp: srcu_struct in which to register the new reader.
*
* Enter an SRCU read-side critical section. Note that SRCU read-side
* critical sections may be nested.
* critical sections may be nested. However, it is illegal to
* call anything that waits on an SRCU grace period for the same
* srcu_struct, whether directly or indirectly. Please note that
* one way to indirectly wait on an SRCU grace period is to acquire
* a mutex that is held elsewhere while calling synchronize_srcu() or
* synchronize_srcu_expedited().
*/
static inline int srcu_read_lock(struct srcu_struct *sp) __acquires(sp)
{