rcu: 1Q2010 update for RCU documentation

Add expedited functions.  Review documentation and update
obsolete verbiage.  Also fix the advice for the RCU CPU-stall
kernel configuration parameter, and document RCU CPU-stall
warnings.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12635142581866-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 12 insertions, 0 deletions

diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 9dba3bb90e60..0e50bc2aa1e2 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -30,6 +30,18 @@ MODULE PARAMETERS
 
 This module has the following parameters:
 
+fqs_duration    Duration (in microseconds) of artificially induced bursts
+                of force_quiescent_state() invocations.  In RCU
+                implementations having force_quiescent_state(), these
+                bursts help force races between forcing a given grace
+                period and that grace period ending on its own.
+
+fqs_holdoff     Holdoff time (in microseconds) between consecutive calls
+                to force_quiescent_state() within a burst.
+
+fqs_stutter     Wait time (in seconds) between consecutive bursts
+                of calls to force_quiescent_state().
+
 irqreaders      Says to invoke RCU readers from irq level.  This is currently
                 done via timers.  Defaults to "1" for variants of RCU that
                 permit this.  (Or, more accurately, variants of RCU that do