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diff --git a/Documentation/RCU/whatisRCU.txt b/Documentation/RCU/whatisRCU.txt
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--- a/Documentation/RCU/whatisRCU.txt
+++ b/Documentation/RCU/whatisRCU.txt
@@ -1,3 +1,11 @@
+Please note that the "What is RCU?" LWN series is an excellent place
+to start learning about RCU:
+
+1. What is RCU, Fundamentally? http://lwn.net/Articles/262464/
+2. What is RCU? Part 2: Usage http://lwn.net/Articles/263130/
+3. RCU part 3: the RCU API http://lwn.net/Articles/264090/
+
+
What is RCU?
RCU is a synchronization mechanism that was added to the Linux kernel
@@ -772,26 +780,18 @@ Linux-kernel source code, but it helps to have a full list of the
APIs, since there does not appear to be a way to categorize them
in docbook. Here is the list, by category.
-Markers for RCU read-side critical sections:
-
- rcu_read_lock
- rcu_read_unlock
- rcu_read_lock_bh
- rcu_read_unlock_bh
- srcu_read_lock
- srcu_read_unlock
-
RCU pointer/list traversal:
rcu_dereference
+ list_for_each_entry_rcu
+ hlist_for_each_entry_rcu
+
list_for_each_rcu (to be deprecated in favor of
list_for_each_entry_rcu)
- list_for_each_entry_rcu
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
- hlist_for_each_entry_rcu
-RCU pointer update:
+RCU pointer/list update:
rcu_assign_pointer
list_add_rcu
@@ -799,16 +799,36 @@ RCU pointer update:
list_del_rcu
list_replace_rcu
hlist_del_rcu
+ hlist_add_after_rcu
+ hlist_add_before_rcu
hlist_add_head_rcu
+ hlist_replace_rcu
+ list_splice_init_rcu()
-RCU grace period:
+RCU: Critical sections Grace period Barrier
+
+ rcu_read_lock synchronize_net rcu_barrier
+ rcu_read_unlock synchronize_rcu
+ call_rcu
+
+
+bh: Critical sections Grace period Barrier
+
+ rcu_read_lock_bh call_rcu_bh rcu_barrier_bh
+ rcu_read_unlock_bh
+
+
+sched: Critical sections Grace period Barrier
+
+ [preempt_disable] synchronize_sched rcu_barrier_sched
+ [and friends] call_rcu_sched
+
+
+SRCU: Critical sections Grace period Barrier
+
+ srcu_read_lock synchronize_srcu N/A
+ srcu_read_unlock
- synchronize_net
- synchronize_sched
- synchronize_rcu
- synchronize_srcu
- call_rcu
- call_rcu_bh
See the comment headers in the source code (or the docbook generated
from them) for more information.