Add an item to the RCU documentation checklist noting that RCU callbacks
can run in parallel.
Signed-off-by: Paul E. McKenney <[EMAIL PROTECTED]>
---
checklist.txt | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff -urpNa -X dontdiff linux-2.6.21/Documentation/RCU/checklist.txt
linux-2.6.21-RCUdoc/Documentation/RCU/checklist.txt
--- linux-2.6.21/Documentation/RCU/checklist.txt 2007-04-25
20:08:32.000000000 -0700
+++ linux-2.6.21-RCUdoc/Documentation/RCU/checklist.txt 2007-06-07
08:58:52.000000000 -0700
@@ -222,7 +222,15 @@ over a rather long period of time, but i
deadlock as soon as the RCU callback happens to interrupt that
acquisition's critical section.
-13. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu())
+13. RCU callbacks can be and are executed in parallel. In many cases,
+ the callback code simply wrappers around kfree(), so that this
+ is not an issue (or, more accurately, to the extent that it is
+ an issue, the memory-allocator locking handles it). However,
+ if the callbacks do manipulate a shared data structure, they
+ must use whatever locking or other synchronization is required
+ to safely access and/or modify that data structure.
+
+14. SRCU (srcu_read_lock(), srcu_read_unlock(), and synchronize_srcu())
may only be invoked from process context. Unlike other forms of
RCU, it -is- permissible to block in an SRCU read-side critical
section (demarked by srcu_read_lock() and srcu_read_unlock()),
-
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