[PATCH -tip 3/3] synchronize_sched_expedited() rcutorture doc

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

This patch updates the rcutorture documentation to include updated
output format.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---

 torture.txt |   17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index a342b6e..f39a3fc 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -162,6 +162,23 @@ of the "old" and "current" counters for the corresponding CPU.  The
 "idx" value maps the "old" and "current" values to the underlying array,
 and is useful for debugging.
 
+Similarly, sched_expedited RCU provides the following:
+
+	sched_expedited-torture: rtc: d0000000016c1880 ver: 1090796 tfle: 0 rta: 1090796 rtaf: 0 rtf: 1090787 rtmbe: 0 nt: 27713319
+	sched_expedited-torture: Reader Pipe:  12660320201 95875 0 0 0 0 0 0 0 0 0
+	sched_expedited-torture: Reader Batch:  12660424885 0 0 0 0 0 0 0 0 0 0
+	sched_expedited-torture: Free-Block Circulation:  1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0
+	state: -1 / 0:0 3:0 4:0
+
+As before, the first four lines are similar to those for RCU.
+The last line shows the task-migration state.  The first number is
+-1 if synchronize_sched_expedited() is idle, -2 if in the process of
+posting wakeups to the migration kthreads, and N when waiting on CPU N.
+Each of the colon-separated fields following the "/" is a CPU:state pair.
+Valid states are "0" for idle, "1" for waiting for quiescent state,
+"2" for passed through quiescent state, and "3" when a race with a
+CPU-hotplug event forces use of the synchronize_sched() primitive.
+
 
 USAGE