smi_aperf_mperf.py

  1#!/bin/env python3
  2# SPDX-License-Identifier: GPL-2.0
  3
  4import subprocess
  5from shutil import which
  6from os import pread
  7
  8# CDLL calls dlopen underneath.
  9# Calling it with None (null), we get handle to the our own image (python interpreter).
 10# We hope to find sched_getcpu() inside ;]
 11# This is a bit ugly, but helps shipping working software, so..
 12try:
 13	import ctypes
 14
 15	this_image = ctypes.CDLL(None)
 16	BASE_CPU = this_image.sched_getcpu()
 17except:
 18	BASE_CPU = 0 # If we fail, set to 0 and pray it's not offline.
 19
 20MSR_IA32_MPERF = 0x000000e7
 21MSR_IA32_APERF = 0x000000e8
 22
 23def check_perf_access():
 24	perf = which('perf')
 25	if perf is None:
 26		print('SKIP: Could not find perf binary, thus could not determine perf access.')
 27		return False
 28
 29	def has_perf_counter_access(counter_name):
 30		proc_perf = subprocess.run([perf, 'stat', '-e', counter_name, '--timeout', '10'],
 31					    capture_output = True)
 32
 33		if proc_perf.returncode != 0:
 34			print(f'SKIP: Could not read {counter_name} perf counter, assuming no access.')
 35			return False
 36
 37		if b'<not supported>' in proc_perf.stderr:
 38			print(f'SKIP: Could not read {counter_name} perf counter, assuming no access.')
 39			return False
 40
 41		return True
 42
 43	if not has_perf_counter_access('msr/mperf/'):
 44		return False
 45	if not has_perf_counter_access('msr/aperf/'):
 46		return False
 47	if not has_perf_counter_access('msr/smi/'):
 48		return False
 49
 50	return True
 51
 52def check_msr_access():
 53	try:
 54		file_msr = open(f'/dev/cpu/{BASE_CPU}/msr', 'rb')
 55	except:
 56		return False
 57
 58	if len(pread(file_msr.fileno(), 8, MSR_IA32_MPERF)) != 8:
 59		return False
 60
 61	if len(pread(file_msr.fileno(), 8, MSR_IA32_APERF)) != 8:
 62		return False
 63
 64	return True
 65
 66has_perf_access = check_perf_access()
 67has_msr_access = check_msr_access()
 68
 69turbostat_counter_source_opts = ['']
 70
 71if has_msr_access:
 72	turbostat_counter_source_opts.append('--no-perf')
 73else:
 74	print('SKIP: doesn\'t have MSR access, skipping run with --no-perf')
 75
 76if has_perf_access:
 77	turbostat_counter_source_opts.append('--no-msr')
 78else:
 79	print('SKIP: doesn\'t have perf access, skipping run with --no-msr')
 80
 81if not has_msr_access and not has_perf_access:
 82	print('SKIP: No MSR nor perf access detected. Skipping the tests entirely')
 83	exit(0)
 84
 85turbostat = which('turbostat')
 86if turbostat is None:
 87	print('Could not find turbostat binary')
 88	exit(1)
 89
 90timeout = which('timeout')
 91if timeout is None:
 92	print('Could not find timeout binary')
 93	exit(1)
 94
 95proc_turbostat = subprocess.run([turbostat, '--list'], capture_output = True)
 96if proc_turbostat.returncode != 0:
 97	print(f'turbostat failed with {proc_turbostat.returncode}')
 98	exit(1)
 99
100EXPECTED_COLUMNS_DEBUG_DEFAULT = b'usec\tTime_Of_Day_Seconds\tAPIC\tX2APIC'
101
102SMI_APERF_MPERF_DEPENDENT_BICS = [
103	'SMI',
104	'Avg_MHz',
105	'Busy%',
106	'Bzy_MHz',
107]
108if has_perf_access:
109	SMI_APERF_MPERF_DEPENDENT_BICS.append('IPC')
110
111for bic in SMI_APERF_MPERF_DEPENDENT_BICS:
112	for counter_source_opt in turbostat_counter_source_opts:
113
114		# Ugly special case, but it is what it is..
115		if counter_source_opt == '--no-perf' and bic == 'IPC':
116			continue
117
118		expected_columns = bic.encode()
119		expected_columns_debug = EXPECTED_COLUMNS_DEBUG_DEFAULT + f'\t{bic}'.encode()
120
121		#
122		# Run turbostat for some time and send SIGINT
123		#
124		timeout_argv = [timeout, '--preserve-status', '-s', 'SIGINT', '-k', '3', '0.2s']
125		turbostat_argv = [turbostat, '-i', '0.50', '--show', bic]
126
127		if counter_source_opt:
128			turbostat_argv.append(counter_source_opt)
129
130		print(f'Running turbostat with {turbostat_argv=}... ', end = '', flush = True)
131		proc_turbostat = subprocess.run(timeout_argv + turbostat_argv, capture_output = True)
132		if proc_turbostat.returncode != 0:
133			print(f'turbostat failed with {proc_turbostat.returncode}')
134			exit(1)
135
136		actual_columns = proc_turbostat.stdout.split(b'\n')[0]
137		if expected_columns != actual_columns:
138			print(f'turbostat column check failed\n{expected_columns=}\n{actual_columns=}')
139			exit(1)
140		print('OK')
141
142		#
143		# Same, but with --debug
144		#
145		turbostat_argv.append('--debug')
146
147		print(f'Running turbostat with {turbostat_argv=}... ', end = '', flush = True)
148		proc_turbostat = subprocess.run(timeout_argv + turbostat_argv, capture_output = True)
149		if proc_turbostat.returncode != 0:
150			print(f'turbostat failed with {proc_turbostat.returncode}')
151			exit(1)
152
153		actual_columns = proc_turbostat.stdout.split(b'\n')[0]
154		if expected_columns_debug != actual_columns:
155			print(f'turbostat column check failed\n{expected_columns_debug=}\n{actual_columns=}')
156			exit(1)
157		print('OK')