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authorDavid S. Miller <davem@davemloft.net>2009-03-26 15:23:24 -0700
committerDavid S. Miller <davem@davemloft.net>2009-03-26 15:23:24 -0700
commit08abe18af1f78ee80c3c3a5ac47c3e0ae0beadf6 (patch)
tree2be39bf8942edca1bcec735145e144a682ca9cd3 /Documentation/RCU/checklist.txt
parentf0de70f8bb56952f6e016a65a8a8d006918f5bf6 (diff)
parent0384e2959127a56d0640505d004d8dd92f9c29f5 (diff)
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts: drivers/net/wimax/i2400m/usb-notif.c
Diffstat (limited to 'Documentation/RCU/checklist.txt')
-rw-r--r--Documentation/RCU/checklist.txt12
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diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt
index 6e253407b3d..accfe2f5247 100644
--- a/Documentation/RCU/checklist.txt
+++ b/Documentation/RCU/checklist.txt
@@ -298,3 +298,15 @@ over a rather long period of time, but improvements are always welcome!
Note that, rcu_assign_pointer() and rcu_dereference() relate to
SRCU just as they do to other forms of RCU.
+
+15. The whole point of call_rcu(), synchronize_rcu(), and friends
+ is to wait until all pre-existing readers have finished before
+ carrying out some otherwise-destructive operation. It is
+ therefore critically important to -first- remove any path
+ that readers can follow that could be affected by the
+ destructive operation, and -only- -then- invoke call_rcu(),
+ synchronize_rcu(), or friends.
+
+ Because these primitives only wait for pre-existing readers,
+ it is the caller's responsibility to guarantee safety to
+ any subsequent readers.