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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-06-23 11:52:59 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2014-07-08 08:32:56 -0700
commit9963185c04727769913a2758c0fcccb821c77098 (patch)
tree02df78882e8f5d9044c5e5772bca0a82fcab623c
parent128ea442b12ba63614dccc9b54726cf753aa4758 (diff)
documentation: Add pointer to percpu-ref for RCU and refcount
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
-rw-r--r--Documentation/RCU/rcuref.txt9
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/RCU/rcuref.txt b/Documentation/RCU/rcuref.txt
index 141d531aa14b..613033ff2b9b 100644
--- a/Documentation/RCU/rcuref.txt
+++ b/Documentation/RCU/rcuref.txt
@@ -1,5 +1,14 @@
Reference-count design for elements of lists/arrays protected by RCU.
+
+Please note that the percpu-ref feature is likely your first
+stop if you need to combine reference counts and RCU. Please see
+include/linux/percpu-refcount.h for more information. However, in
+those unusual cases where percpu-ref would consume too much memory,
+please read on.
+
+------------------------------------------------------------------------
+
Reference counting on elements of lists which are protected by traditional
reader/writer spinlocks or semaphores are straightforward: