From 6fb5eae6449ba327784914c26b46952f199a5080 Mon Sep 17 00:00:00 2001
From: Michal Berger <michal.berger@intel.com>
Date: Sun, 30 Oct 2022 22:15:28 +0100
Subject: [PATCH] perf/pm: Collect power statistics per CPU socket

This uses RAPL's powercap interface under sysfs. The alternative is
to use MSRs directly, but with this we don't have to bother about
different cpu models, etc. as kernel does that for us here.

Signed-off-by: Michal Berger <michal.berger@intel.com>
Change-Id: I91ed5d67edf2669b9d7b271bbc02ecc61a6a3ea2
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15182
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
---
 scripts/perf/pm/collect-bmc-pm | 67 ++++++++++++++++++++++++++++++++--
 1 file changed, 63 insertions(+), 4 deletions(-)

diff --git a/scripts/perf/pm/collect-bmc-pm b/scripts/perf/pm/collect-bmc-pm
index 0f9b1c213..7fee16e1d 100755
--- a/scripts/perf/pm/collect-bmc-pm
+++ b/scripts/perf/pm/collect-bmc-pm
@@ -210,7 +210,11 @@ sdr_power_support() {
 }
 
 power_support() {
-	local -g support
+	local -g support cpu_support=0
+
+	if ((include_cpu == 1)) && rapl_supported; then
+		cpu_support=1
+	fi
 
 	if [[ $interface == dcmi || $interface == sdr ]]; then
 		# override
@@ -221,7 +225,11 @@ power_support() {
 	elif sdr_power_support; then
 		support=sdr
 	else
-		printf 'BMC does not provide Power Management support, cannot gather power measurements\n' >&2
+		printf 'BMC does not provide Power Management support, cannot gather system-wide power measurements\n' >&2
+		if ((cpu_support)); then
+			printf 'Only CPU measurements will be provided\n' >&2
+			return 0
+		fi
 		return 1
 	fi
 }
@@ -304,6 +312,49 @@ get_sdr_now_reading() {
 	done
 }
 
+rapl_supported() {
+	[[ -e /sys/class/powercap/intel-rapl ]]
+}
+
+get_cpu_socket_reading() {
+	local rapl=/sys/class/powercap
+	local socket socket_idx _socket_idx socket_name
+	local ts reading
+
+	# power_uw is usually not available so we need to relay on energy_uj. It's also rarely
+	# rw so we can't zero it out, hence we need to keep track of the initial counter. For
+	# details see kernel documentation (powercap.rst).
+	ts=$(utc)
+	for socket in /sys/class/powercap/intel-rapl:*; do
+		[[ -e $socket ]] || continue
+
+		socket_idx=${socket#*:} socket_name=$(< "$socket/name")
+		# Adjust for different domains, see linux/intel_rapl.h
+		case "$socket_name" in
+			dram | core | uncore) _socket_idx=${socket_idx//:/_} socket_idx=${socket_idx%:*} ;;
+			package-*) _socket_idx=$socket_idx socket_name=socket ;;
+			psys*) _socket_idx=$socket_idx socket_name=platform ;;
+		esac
+
+		local -n socket_uj=socket_${_socket_idx}_uj
+		socket_uj+=("$(< "$socket/energy_uj")")
+		# We need at least two readings for comparison
+		((${#socket_uj[@]} > 1)) || continue
+
+		# Convert to Watts - use bc since $interval can be an actual float
+		reading=$(bc <<< "scale=2; (${socket_uj[-1]} - ${socket_uj[-2]}) / 1000000 / $interval")
+		eval "_socket${_socket_idx}_readings+=($reading)"
+		power_readings["$socket_name-$socket_idx"]="_socket${_socket_idx}_readings[@]"
+
+		printf '(%s) CPU %s %s reading: %s Watts (interval: %ss)\n' \
+			"$ts" \
+			"$socket_name" \
+			"$socket_idx" \
+			"$reading" \
+			"$interval" >&2
+	done
+}
+
 get_now_reading() {
 	case "$support" in
 		dcmi) get_dcmi_now_reading ;;
@@ -349,8 +400,13 @@ cleanup() {
 
 collect_readings() {
 	local _count=$count
+	if ((_count == 1 && cpu_support)); then
+		# We need at least two readings to get a meaningful data
+		((_count += 1))
+	fi
 	while ((count <= 0 ? 1 : _count--)); do
 		get_now_reading
+		((cpu_support)) && get_cpu_socket_reading
 		sleep "${interval}s"
 	done
 }
@@ -358,7 +414,7 @@ collect_readings() {
 help() {
 	cat <<- HELP
 
-		Usage: $0 [-h] [-d dir] [-i sdr|dcmi] [-s SENSOR_NAME] [-t interval] [-l log_file] [-p prefix] [-c count]
+		Usage: $0 [-h] [-d dir] [-i sdr|dcmi] [-s SENSOR_NAME] [-t interval] [-l log_file] [-p prefix] [-c count] [-r]
 
 		  -h - Print this message.
 		  -d - Directory where the results should be saved. Default is /tmp.
@@ -375,6 +431,7 @@ help() {
 		  -p - Add prefix to saved files.
 		  -c - Read power usage count times. 0 is the default and it means to run
 		       indefinitely.
+		  -r - Include readings from CPU sockets (RAPL-dependent)
 
 		When started, ${0##*/} will enter loop to continuously read power usage from either
 		DCMI interface or dedicated Watts sensors every interval. Each reading will be
@@ -392,11 +449,12 @@ remove_sdr_cache=yes
 log_to_file=no
 prefix=""
 count=0
+include_cpu=0
 
 declare -A power_readings=()
 declare -a extra_power_sensors=()
 
-while getopts :hi:s:d:t:xlp:c: arg; do
+while getopts :hi:s:d:t:xlp:c:r arg; do
 	case "$arg" in
 		h)
 			help
@@ -410,6 +468,7 @@ while getopts :hi:s:d:t:xlp:c: arg; do
 		l) log_to_file=yes ;;
 		p) prefix=$OPTARG ;;
 		c) count=$OPTARG ;;
+		r) include_cpu=1 ;;
 		*) ;;
 	esac
 done