Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm

[pandora-kernel.git] / Documentation / RCU / trace.txt

diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt
index 8173cec..c078ad4 100644 (file)
--- a/Documentation/RCU/trace.txt
+++ b/Documentation/RCU/trace.txt
@@ -99,11 +99,18 @@ o   "qp" indicates that RCU still expects a quiescent state from
 
 o      "dt" is the current value of the dyntick counter that is incremented
        when entering or leaving dynticks idle state, either by the
-       scheduler or by irq.  This number is even if the CPU is in
-       dyntick idle mode and odd otherwise.  The number after the first
-       "/" is the interrupt nesting depth when in dyntick-idle state,
-       or one greater than the interrupt-nesting depth otherwise.
-       The number after the second "/" is the NMI nesting depth.
+       scheduler or by irq.  The number after the "/" is the interrupt
+       nesting depth when in dyntick-idle state, or one greater than
+       the interrupt-nesting depth otherwise.
+
+       This field is displayed only for CONFIG_NO_HZ kernels.
+
+o      "dn" is the current value of the dyntick counter that is incremented
+       when entering or leaving dynticks idle state via NMI.  If both
+       the "dt" and "dn" values are even, then this CPU is in dynticks
+       idle mode and may be ignored by RCU.  If either of these two
+       counters is odd, then RCU must be alert to the possibility of
+       an RCU read-side critical section running on this CPU.
 
        This field is displayed only for CONFIG_NO_HZ kernels.