adding some documentation

tests/performance/Makefile.am

@@ -30,7 +30,7 @@ pioperformance_SOURCES = pioperformance.F90
 # Tests will run from a bash script.
 #TESTS = run_tests.sh
 
-EXTRA_DIST = CMakeLists.txt gensimple.pl
+EXTRA_DIST = CMakeLists.txt gensimple.pl Pioperformance.md
 
 # Clean up files produced during testing.
 CLEANFILES = *.nc *.log *.mod

tests/performance/Pioperformance.md

@@ -0,0 +1,20 @@
+To run pioperformance you need a dof input file. I have a whole repo
+of them here:
+https://svn-ccsm-piodecomps.cgd.ucar.edu/trunk
+
+You need an input namelist:
+
+&pioperf
+decompfile=   '/gpfs/fs1/work/jedwards/sandboxes/piodecomps/576/piodecomp576tasks03dims01.dat',
+ pio_typenames = 'pnetcdf'
+ rearrangers = 1,2
+ nframes = 1
+ nvars = 1
+ niotasks = 64, 32, 16
+ /
+
+in the namelist all of the inputs are arrays and it will test all
+combinations of the inputs.  You need to run it on the number of tasks
+specified by the input dof There are also some options to use simple
+generated dof's instead of files.
+