Project Stage 1

Photo by SpaceX on Unsplash

Hello! This is my SPO 600 blog, and this post will be long – sorry. The goal is to pick one project that is CPU intensive, written in C or C++, and experiment different compiler options and present the results. That’s why it will be long – lots of data to show.

I choose the AWK project (https://github.com/onetrueawk/awk). It is a handy tool to process files. Parse, sort, and filter are some trivial operations that are CPU intensive. To make it harder, I created a huge XML file to parse it and count the tags.

I've described the machines in my last post, if you miss it, here it is.

I also created a script to run and collect the data. I planned to run each candidate 10 times, but a few attempts didn’t receive any data. So, I decided to nest the loop in a way that even if someone kills my process, the data could be used. Guess what? It happened!

To produce the candidates, I just changed the CFLAGS inside the makefile and ran the make command. I took care to clean everything between the compilations. Here is the list of the candidates:

awkO0 – CFLAGS = -O0 – optimization for compilation time (default)
awkO1 – CFLAGS = -O1 – optimization for code size and execution time
awkO2 – CFLAGS = -O2 – optimization more for code size and execution time
awkO3 – CFLAGS = -O3 – optimization more for code size and execution time
awkOs – CFLAGS = -Os – optimization for code size

Overall, the awkO3 performed better on all machines – except on Ccharlie. The awkO0 and awkOs are 60% and 15% slower than the optimum.  In the Arch64 architecture, the awk01, awk02 and awkO3 performed somewhat the same. However, in the x86_64 architecture, the optimization gain is evident between them. Maybe there is room to improve the Arch64 compiler flags -O1, -O2 and -O3.

Here is the complete data. The time axis is in seconds. See you next post.

	#!/bin/bash
	QTY=10
	FILE_EXE='exe.txt'
	FILE_RPT='rpt.txt'
	# clean the data files
	for EXE in awkO0 awkO1 awkO2 awkO3 awkOs; do
	> $EXE'_'$FILE_EXE
	> $EXE'_'$FILE_RPT
	done
	# run the tests
	for ((n=0;n<$QTY;n++))
	do
	for EXE in awkO0 awkO1 awkO2 awkO3 awkOs; do
	echo "$(date +"%Y-%m-%d %H:%M:%S,%3N") - $EXE - INI: $n"
	T0=$(date +%s)
	time ./$EXE 'BEGIN {FS = "<|:|=";} {if ($8 == "DDD>") a ++;} END {print "count: " a;}' bmark-data.txt
	T1=$(date +%s)
	echo "$(date +"%Y-%m-%d %H:%M:%S,%3N") - $EXE - FIN: $n"
	echo $((T1 - T0)) >> $EXE'_'$FILE_EXE
	echo ''
	done
	done
	# generate the report
	for EXE in awkO0 awkO1 awkO2 awkO3 awkOs; do
	> $EXE'_'$FILE_RPT
	awk '{
	if (min == "") { min = max = $1 };
	if ($1 > max) { max = $1 };
	if ($1 < min) { min = $1 };
	sum += $1
	} END {
	print "Executions: " NR "\nMin Time : " min "\nMax Time : " max "\nAvg time : " sum/NR
	}' $EXE'_'$FILE_EXE > $EXE'_'$FILE_RPT
	done

view raw tester_project_stage1.sh hosted with ❤ by GitHub