Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
doc: Further updates to RCU's lockdep.rst
This commit wordsmiths RCU's lockdep.rst.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
+6
-7
+6
-7
Documentation/RCU/lockdep.rst
+6
-7
Documentation/RCU/lockdep.rst
···
69
69
value of the pointer itself, for example, against NULL.
70
70
71
71
The rcu_dereference_check() check expression can be any boolean
72
-
expression, but would normally include a lockdep expression. However,
73
-
any boolean expression can be used. For a moderately ornate example,
74
-
consider the following::
72
+
expression, but would normally include a lockdep expression. For a
73
+
moderately ornate example, consider the following::
75
74
76
75
file = rcu_dereference_check(fdt->fd[fd],
77
76
lockdep_is_held(&files->file_lock) ||
···
96
97
atomic_read(&files->count) == 1);
97
98
98
99
This would verify cases #2 and #3 above, and furthermore lockdep would
99
-
complain if this was used in an RCU read-side critical section unless one
100
-
of these two cases held. Because rcu_dereference_protected() omits all
101
-
barriers and compiler constraints, it generates better code than do the
102
-
other flavors of rcu_dereference(). On the other hand, it is illegal
100
+
complain even if this was used in an RCU read-side critical section unless
101
+
one of these two cases held. Because rcu_dereference_protected() omits
102
+
all barriers and compiler constraints, it generates better code than do
103
+
the other flavors of rcu_dereference(). On the other hand, it is illegal
103
104
to use rcu_dereference_protected() if either the RCU-protected pointer
104
105
or the RCU-protected data that it points to can change concurrently.
105
106