From 7b7e1b7b7f6f16862ba5bfe79f024139e61b6623 Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Tue, 13 Jan 2015 15:59:30 +0100 Subject: [PATCH] lockstat: Add documentation on contention and contenting points Signed-off-by: Daniel Wagner Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Jonathan Corbet Signed-off-by: Jonathan Corbet --- Documentation/locking/lockstat.txt | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/Documentation/locking/lockstat.txt b/Documentation/locking/lockstat.txt index 7428773a1e69..568bbbacee91 100644 --- a/Documentation/locking/lockstat.txt +++ b/Documentation/locking/lockstat.txt @@ -121,6 +121,11 @@ show the header with column descriptions. Lines 05-18 and 20-31 show the actual statistics. These statistics come in two parts; the actual stats separated by a short separator (line 08, 13) from the contention points. +Lines 09-12 show the first 4 recorded contention points (the code +which tries to get the lock) and lines 14-17 show the first 4 recorded +contended points (the lock holder). It is possible that the max +con-bounces point is missing in the statistics. + The first lock (05-18) is a read/write lock, and shows two lines above the short separator. The contention points don't match the column descriptors, they have two: contentions and [] symbol. The second set of contention