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authorPaul E. McKenney <paul.mckenney@linaro.org>2011-11-16 17:48:21 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2011-12-11 10:31:56 -0800
commitb58bdccaa8d908e0f71dae396468a0d3f7bb3125 (patch)
treec03e6b8691a6569407c69b3456df88094d70309a /Documentation/RCU/torture.txt
parenta95f8817f8afa75ab41728bd1bb65024c65c91c3 (diff)
downloadlinux-b58bdccaa8d908e0f71dae396468a0d3f7bb3125.tar.gz
rcu: Add rcutorture CPU-hotplug capability
Running CPU-hotplug operations concurrently with rcutorture has
historically been a good way to find bugs in both RCU and CPU hotplug.
This commit therefore adds an rcutorture module parameter called
"onoff_interval" that causes a randomly selected CPU-hotplug operation to
be executed at the specified interval, in seconds.  The default value of
"onoff_interval" is zero, which disables rcutorture-instigated CPU-hotplug
operations.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'Documentation/RCU/torture.txt')
-rw-r--r--Documentation/RCU/torture.txt8
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index af40929e1cb0..d67068d0d2b9 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -61,6 +61,14 @@ nreaders	This is the number of RCU reading threads supported.
 		To properly exercise RCU implementations with preemptible
 		read-side critical sections.
 
+onoff_interval
+		The number of seconds between each attempt to execute a
+		randomly selected CPU-hotplug operation.  Defaults to
+		zero, which disables CPU hotplugging.  In HOTPLUG_CPU=n
+		kernels, rcutorture will silently refuse to do any
+		CPU-hotplug operations regardless of what value is
+		specified for onoff_interval.
+
 shuffle_interval
 		The number of seconds to keep the test threads affinitied
 		to a particular subset of the CPUs, defaults to 3 seconds.