rcu: Add synchronize_sched_expedited() rcutorture doc + updates
This patch updates the rcutorture documentation to include
updated output format. It also brings the RCU documentation up
to date.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Cc: davem@davemloft.net
Cc: dada1@cosmosbay.com
Cc: zbr@ioremap.net
Cc: jeff.chua.linux@gmail.com
Cc: paulus@samba.org
Cc: laijs@cn.fujitsu.com
Cc: jengelh@medozas.de
Cc: r000n@r000n.net
Cc: benh@kernel.crashing.org
Cc: mathieu.desnoyers@polymtl.ca
LKML-Reference: <12459460983193-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index a342b6e..9dba3bb 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -76,8 +76,10 @@
"rcu_sync" for rcu_read_lock() with synchronous reclamation,
"rcu_bh" for the rcu_read_lock_bh() API, "rcu_bh_sync" for
rcu_read_lock_bh() with synchronous reclamation, "srcu" for
- the "srcu_read_lock()" API, and "sched" for the use of
- preempt_disable() together with synchronize_sched().
+ the "srcu_read_lock()" API, "sched" for the use of
+ preempt_disable() together with synchronize_sched(),
+ and "sched_expedited" for the use of preempt_disable()
+ with synchronize_sched_expedited().
verbose Enable debug printk()s. Default is disabled.
@@ -162,6 +164,23 @@
"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