Add a script for calibrating settings for timing configurations.

Update the timings scripts with calibrated settings that run
a full build between 9.5 and 10.0 seconds on the buildbot slave.

1 files changed, 24 insertions, 5 deletions

diff --git a/timings/JTimer/TimeSCons-run.py b/timings/JTimer/TimeSCons-run.py
index 05ffbfb9..7fe1bf40 100644
--- a/timings/JTimer/TimeSCons-run.py
+++ b/timings/JTimer/TimeSCons-run.py
@@ -25,10 +25,10 @@
 This configuration is for timing how we evaluate long chains of
 dependencies, specifically when -j is used.
 
-We set up a chain of 500 targets that get built from a Python function
-action with no source files (equivalent to "echo junk > $TARGET").
-Each target explicitly depends on the next target in turn, so the
-Taskmaster will do a deep walk of the dependency graph.
+We set up a chain of $TARGET_COUNT targets that get built from a
+Python function action with no source files (equivalent to "echo junk >
+$TARGET").  Each target explicitly depends on the next target in turn,
+so the Taskmaster will do a deep walk of the dependency graph.
 
 This test case was contributed by Kevin Massey.  Prior to revision 1468,
 we had a serious O(N^2) problem in the Taskmaster when handling long
@@ -38,7 +38,26 @@ to the Taskmaster so it could be smarter about not re-evaluating Nodes.
 
 import TestSCons
 
-test = TestSCons.TimeSCons(variables={'TARGET_COUNT':500})
+# Full-build time of just under 10 seconds on ubuntu-timings slave,
+# as determined by bin/calibrate.py on 9 December 2009:
+#
+# run   1:   3.211:  TARGET_COUNT=50
+# run   2:  11.920:  TARGET_COUNT=155
+# run   3:   9.182:  TARGET_COUNT=130
+# run   4:  10.185:  TARGET_COUNT=141
+# run   5:   9.945:  TARGET_COUNT=138
+# run   6:  10.035:  TARGET_COUNT=138
+# run   7:   9.898:  TARGET_COUNT=137
+# run   8:   9.840:  TARGET_COUNT=137
+# run   9:  10.054:  TARGET_COUNT=137
+# run  10:   9.747:  TARGET_COUNT=136
+# run  11:   9.778:  TARGET_COUNT=136
+# run  12:   9.743:  TARGET_COUNT=136
+#
+# The fact that this varies so much suggests that it's pretty
+# non-deterministic, which makes sense for a test involving -j.
+
+test = TestSCons.TimeSCons(variables={'TARGET_COUNT':136})
 
 test.main()