scripts: Plot memory benchmarks using gnuplot

Now that we have memory usage benchmarks collected at our disposal,
introduce a gnuplot script to plot the newest version.

To avoid scaling issues, memory is plotted in a "double y axis" form,
with VM usage on the left, and dirty RSS memory usage on the right.

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>

Makefile.am

@@ -28,6 +28,7 @@ EXTRA_DIST = \
 	PROTOCOL \
 	README \
 	scripts/benchmark_memory_usage.sh \
+	scripts/plot_memory_usage.gp \
 	scripts/benchmarks/README \
 	todo \
 	.gitignore \

scripts/benchmark_memory_usage.sh

@@ -53,6 +53,7 @@ PA_PLAY_PROCESS_NAME="paplay"
 
 SCRIPTS_DIR=${PA_HOME}/scripts
 BENCHMARKS_DIR=${SCRIPTS_DIR}/benchmarks
+GNUPLOT_SCRIPT=${SCRIPTS_DIR}/plot_memory_usage.gp
 OUTPUT_FILE=${BENCHMARKS_DIR}/memory-usage-`date -Iseconds`.txt
 SYMLINK_LATEST_OUTPUT_FILE=${BENCHMARKS_DIR}/memory-usage-LATEST.txt
 
@@ -129,3 +130,4 @@ ln -s $OUTPUT_FILE $SYMLINK_LATEST_OUTPUT_FILE
 
 msg "Sampling daemon memory usage done!"
 msg "Check the results at $SYMLINK_LATEST_OUTPUT_FILE"
+msg "Plot these results using 'gnuplot $GNUPLOT_SCRIPT'"

scripts/plot_memory_usage.gp

@@ -0,0 +1,63 @@
+
+# This file is part of PulseAudio.
+#
+# Copyright 2015 Ahmed S. Darwish <darwish.07@gmail.com>
+#
+# PulseAudio is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# PulseAudio is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+
+#
+# PulseAudio memory usage plotting script
+#
+# Before invocation, generate necessary data by running the
+# 'benchmark_memory_usage.sh' bash script. Afterwards, you can plot
+# such data by running:
+#
+#       gnuplot plot_memory_usage.gp
+#
+# Note! To avoid scaling issues, memory is plotted in a "double y axis"
+# form, with VM usage on the left, and dirty RSS memory usage on the
+# right. The scales are different.
+#
+
+# Print our user messages to the stdout
+set print "-"
+
+benchDir = system('dirname ' .ARG0) .'/benchmarks/'
+inputFile = benchDir ."memory-usage-LATEST.txt"
+outputFile = benchDir ."pulse-memory-usage.png"
+
+set title "PulseAudio Memory Usage Over Time"
+set xlabel "Number of councurrent 'paplay' clients"
+
+set ylabel "Virtual memory consumption (GiB)"
+set y2label "Dirty RSS consumption (MiB)"
+set ytics nomirror
+set y2tics
+
+# Finer granulrity for x-axis ticks ...
+set xtics 1,1
+set grid
+
+# Use Cairo's PNG backend. This produce images which are way
+# better-rendered than the barebone classical png backend
+set terminal pngcairo enhanced size 1000,768 font 'Verdana,10'
+set output outputFile
+
+print "Plotting data from input file: ", inputFile
+print "..."
+
+plot inputFile using 1:($2/1024/1024) title "VmSize" axes x1y1 with linespoints, \
+     inputFile using 1:($3/1024) title "Dirty RSS" axes x1y2 with linespoints
+
+print "Done! Check our performance at: ", outputFile