#!/bin/bash
# Watch CPU temperature while compiling
#
# Author: Peter Wu <lekensteyn@gmail.com>
# Created: 2013-07-31

GITREPO=${GITREPO:-$HOME/Linux-src/linux}
SRCDIR=${SRCDIR:-/tmp/linux-src}
BUILDDIR=${BUILDDIR:-/tmp/linux-build}
LOGDIR=${LOGDIR:-.}

for arg; do
	# Clear all arguments in order to print usage message.
	case $arg in
	--help|-h)
		set --
		break
		;;
	esac
	if ! [[ $arg -gt 0 ]]; then
		echo "Invalid number: $arg" >&2
		exit 1
	fi
done

if [ $# -lt 2 ]; then
	cat <<EOF
Usage: $0 repetitions cores1 [cores2 ... coresN]

Use at least three repetitions to get a reliable average. Specify a
number of cores to test. For example, to compare a dual core against a
quad core CPU, I used the following:

    $0 3   4 8 12 16

Timings and results will be written to stdout.

The following environment vars are available:

# Path to Linux git repository (to fetch sources from). Unused if
# SRCDIR is given which contains a 'version' file.
GITREPO=$GITREPO

# Directory to build the kernel from. If there is no 'version' file,
# the directory will be removed and created from sources in GITREPO.
SRCDIR=$SRCDIR

# Output directory for object files.
BUILDDIR=$BUILDDIR

# Directory to store temperature readings.
LOGDIR=$LOGDIR
EOF
	exit 1
fi

# Begin logic

if ! [ -e "$SRCDIR/version" ]; then
	if [ -d "$SRCDIR/.git" ]; then
		echo "$SRCDIR is a git repo, which I will not delete." >&2
		echo "Create the 'version' file in the SRCDIR directory" >&2
		echo "or specify a different target SRCDIR." >&2
		exit 1
	fi
	rm -rf "$SRCDIR"
	mkdir "$SRCDIR"
	if ! (cd "$GITREPO" && git describe) > "$SRCDIR/version"; then
		echo "$GITREPO is not a git repo? Aborting!" >&2
		exit 1
	fi
	(cd "$GITREPO" && time git archive HEAD) | tar x -C "$SRCDIR"
fi
cat "$SRCDIR/version"

mk() {
	make -C "$SRCDIR" O="$BUILDDIR" "$@"
}

get_temps() {
	cat /sys/devices/platform/coretemp.0/temp*_input |
		tr '\n' '\t' | sed 's/\t$/\n/'
}

temp_logger() {
	local name=$1
	mkdir -p "$LOGDIR"
	while sleep 1; do
		get_temps
	done > "$LOGDIR/$name"
}

run() {
	local tag jobs sec1 sec2 logpid templog

	tag=$1
	jobs=$2
	templog="temps-$tag-$jobs"

	rm -rf "$BUILDDIR"
	mkdir "$BUILDDIR"

	mk defconfig >/dev/null 2>&1

	echo
	echo "Running $tag-$jobs"
	temp_logger "$templog" & logpid=$!
	trap "kill $logpid" EXIT
	{ time {
		sec1=$(date +%s)
		mk -j$jobs bzImage modules >/dev/null 2>&1
		sec2=$(date +%s)
		echo "jobs=$jobs  secs=$((sec2-sec1))"
		echo -n "loadavg: "
		cut -d\  -f1-3 /proc/loadavg
	}; } 2>&1
	kill $logpid; wait $logpid 2>/dev/null

	# Very simple statistics
	echo "Temperature (min / avg / max):"
	awk '
	{
		for (i=0; i<NF; i++) {
			sum[i] += $i / 1000;
			if (max[i] < $i) max[i] = $i;
			if (min[i] == "" || min[i] > $i) min[i] = $i;
		}
		count++;
	}
	END {
		for (i in sum) {
			avg = sum[i] / count;
			print min[i] / 1000, "/", avg, "/", max[i] / 1000
		}
	}
	' "$LOGDIR/$templog"
}

resdir="res-$(date +%Y%m%d-%H%M%S)"
mkdir -v "$resdir"
cd "$resdir"

trials=$1; shift
for ((trial_no=1; trial_no<=trials; trial_no++)); do
	for jobs; do
		run $trial_no $jobs
	done
done

#rm -rf "$BUILDDIR" "$SRCDIR"