Update help text and documentaition.

Tools/pybench/README

@@ -46,6 +46,9 @@ Options and default settings:
   -w arg           set warp factor to arg (20)
   -d               hide noise in compares (0)
   --no-gc          disable garbage collection (0)
+  --no-syscheck    "disable" sys check interval (set to sys.maxint) (0)
+  -t arg           tests containing substring ()
+  -C arg           number of calibration runs (20)
   -v               generate verbose output
   -h               show this help text
   --help           show this help text
@@ -366,6 +369,14 @@ symbols defined in that module for subclasses of pybench.Test and
 automatically add them to the benchmark suite.
 
 
+Breaking Comparability
+----------------------
+
+If a change is made to any individual test that means it is no
+longer strcitly comparable with previous runs, the '.version' class
+variable should be updated. Therefafter, comparisons with previous
+versions of the test will list as "n/a" to reflect the change.
+
 Have fun,
 --
 Marc-Andre Lemburg

Tools/pybench/pybench.py

@@ -382,7 +382,7 @@ class PyBenchCmdline(Application):
                SwitchOption('--no-syscheck',
                     '"disable" sys check interval (set to sys.maxint)', 0),
                ArgumentOption('-t', 'tests containing substring', ''),
-               ArgumentOption('-C', 'number of calibration runs (default 20)', 20)
+               ArgumentOption('-C', 'number of calibration runs', 20)
                ]
 
     about = """\