From d0cde2879f7eee3b3096d815eca21464fdc664d3 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 31 Oct 2012 13:22:08 -0700 Subject: [PATCH] --- yaml --- r: 338799 b: refs/heads/master c: d484a215139cf556cb718a7ec7042260b7fc2d28 h: refs/heads/master i: 338797: 52cc016762ae2db4457d75a589175faee9d689f7 338795: 6ff7d22531df7f9e63fade09a4fbc96bdcce8dfc 338791: c01ffba4f3c1f0a8d6d7a0c50bef24e9456e6ed7 338783: aa1f13ca06cf748c48a823afd426741d9e25739d v: v3 --- [refs] | 2 +- trunk/Documentation/RCU/trace.txt | 41 +++++++++++++++++++++++++++++++ 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/[refs] b/[refs] index 7dae4e5394cd..c67567ac1705 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 40e80c469f1b52a68e09da3808a1228cf9947fa7 +refs/heads/master: d484a215139cf556cb718a7ec7042260b7fc2d28 diff --git a/trunk/Documentation/RCU/trace.txt b/trunk/Documentation/RCU/trace.txt index 79ce9891a8c7..c776968f4463 100644 --- a/trunk/Documentation/RCU/trace.txt +++ b/trunk/Documentation/RCU/trace.txt @@ -41,6 +41,8 @@ also rcu/rcu_preempt) the following files will be present: rcudata: Displays fields in struct rcu_data. +rcuexp: + Displays statistics for expedited grace periods. rcugp: Displays grace-period counters. rcuhier: @@ -233,6 +235,45 @@ o "ktl" is the low-order 16 bits (in hexadecimal) of the count of This field is displayed only for CONFIG_RCU_BOOST kernels. +The output of "cat rcu/rcu_preempt/rcuexp" looks as follows: + +s=21872 d=21872 w=0 tf=0 wd1=0 wd2=0 n=0 sc=21872 dt=21872 dl=0 dx=21872 + +These fields are as follows: + +o "s" is the starting sequence number. + +o "d" is the ending sequence number. When the starting and ending + numbers differ, there is an expedited grace period in progress. + +o "w" is the number of times that the sequence numbers have been + in danger of wrapping. + +o "tf" is the number of times that contention has resulted in a + failure to begin an expedited grace period. + +o "wd1" and "wd2" are the number of times that an attempt to + start an expedited grace period found that someone else had + completed an expedited grace period that satisfies the + attempted request. "Our work is done." + +o "n" is number of times that contention was so great that + the request was demoted from an expedited grace period to + a normal grace period. + +o "sc" is the number of times that the attempt to start a + new expedited grace period succeeded. + +o "dt" is the number of times that we attempted to update + the "d" counter. + +o "dl" is the number of times that we failed to update the "d" + counter. + +o "dx" is the number of times that we succeeded in updating + the "d" counter. + + The output of "cat rcu/rcu_preempt/rcugp" looks as follows: completed=31249 gpnum=31250 age=1 max=18