Quelle  smi_aperf_mperf.py   Sprache: Python

#!/bin/env python3
# SPDX-License-Identifier: GPL-2.0

import subprocess
from shutil import which
from os import pread

# CDLL calls dlopen underneath.
# Calling it with None (null), we get handle to the our own image (python interpreter).
# We hope to find sched_getcpu() inside ;]
# This is a bit ugly, but helps shipping working software, so..
try:
 import ctypes

 this_image = ctypes.CDLL(None)
 BASE_CPU = this_image.sched_getcpu()
except:
 BASE_CPU = 0 # If we fail, set to 0 and pray it's not offline.

MSR_IA32_MPERF = 0x000000e7
MSR_IA32_APERF = 0x000000e8

def check_perf_access():
 perf = which('perf')
 if perf is None:
  print('SKIP: Could not find perf binary, thus could not determine perf access.')
  return False

 def has_perf_counter_access(counter_name):
  proc_perf = subprocess.run([perf, 'stat', '-e', counter_name, '--timeout', '10'],
         capture_output = True)

  if proc_perf.returncode != 0:
   print(f'SKIP: Could not read {counter_name} perf counter, assuming no access.')
   return False

  if b'' in proc_perf.stderr:
   print(f'SKIP: Could not read {counter_name} perf counter, assuming no access.')
   return False

  return True

 if not has_perf_counter_access('msr/mperf/'):
  return False
 if not has_perf_counter_access('msr/aperf/'):
  return False
 if not has_perf_counter_access('msr/smi/'):
  return False

 return True

def check_msr_access():
 try:
  file_msr = open(f'/dev/cpu/{BASE_CPU}/msr', 'rb')
 except:
  return False

 if len(pread(file_msr.fileno(), 8, MSR_IA32_MPERF)) != 8:
  return False

 if len(pread(file_msr.fileno(), 8, MSR_IA32_APERF)) != 8:
  return False

 return True

has_perf_access = check_perf_access()
has_msr_access = check_msr_access()

turbostat_counter_source_opts = ['']

if has_msr_access:
 turbostat_counter_source_opts.append('--no-perf')
else:
 print('SKIP: doesn\'t have MSR access, skipping run with --no-perf')

if has_perf_access:
 turbostat_counter_source_opts.append('--no-msr')
else:
 print('SKIP: doesn\'t have perf access, skipping run with --no-msr')

if not has_msr_access and not has_perf_access:
 print('SKIP: No MSR nor perf access detected. Skipping the tests entirely')
 exit(0)

turbostat = which('turbostat')
if turbostat is None:
 print('Could not find turbostat binary')
 exit(1)

timeout = which('timeout')
if timeout is None:
 print('Could not find timeout binary')
 exit(1)

proc_turbostat = subprocess.run([turbostat, '--list'], capture_output = True)
if proc_turbostat.returncode != 0:
 print(f'turbostat failed with {proc_turbostat.returncode}')
 exit(1)

EXPECTED_COLUMNS_DEBUG_DEFAULT = b'usec\tTime_Of_Day_Seconds\tAPIC\tX2APIC'

SMI_APERF_MPERF_DEPENDENT_BICS = [
 'SMI',
 'Avg_MHz',
 'Busy%',
 'Bzy_MHz',
]
if has_perf_access:
 SMI_APERF_MPERF_DEPENDENT_BICS.append('IPC')

for bic in SMI_APERF_MPERF_DEPENDENT_BICS:
 for counter_source_opt in turbostat_counter_source_opts:

  # Ugly special case, but it is what it is..
  if counter_source_opt == '--no-perf' and bic == 'IPC':
   continue

  expected_columns = bic.encode()
  expected_columns_debug = EXPECTED_COLUMNS_DEBUG_DEFAULT + f'\t{bic}'.encode()

  #
  # Run turbostat for some time and send SIGINT
  #
  timeout_argv = [timeout, '--preserve-status', '-s', 'SIGINT', '-k', '3', '0.2s']
  turbostat_argv = [turbostat, '-i', '0.50', '--show', bic]

  if counter_source_opt:
   turbostat_argv.append(counter_source_opt)

  print(f'Running turbostat with {turbostat_argv=}... ', end = '', flush = True)
  proc_turbostat = subprocess.run(timeout_argv + turbostat_argv, capture_output = True)
  if proc_turbostat.returncode != 0:
   print(f'turbostat failed with {proc_turbostat.returncode}')
   exit(1)

  actual_columns = proc_turbostat.stdout.split(b'\n')[0]
  if expected_columns != actual_columns:
   print(f'turbostat column check failed\n{expected_columns=}\n{actual_columns=}')
   exit(1)
  print('OK')

  #
  # Same, but with --debug
  #
  turbostat_argv.append('--debug')

  print(f'Running turbostat with {turbostat_argv=}... ', end = '', flush = True)
  proc_turbostat = subprocess.run(timeout_argv + turbostat_argv, capture_output = True)
  if proc_turbostat.returncode != 0:
   print(f'turbostat failed with {proc_turbostat.returncode}')
   exit(1)

  actual_columns = proc_turbostat.stdout.split(b'\n')[0]
  if expected_columns_debug != actual_columns:
   print(f'turbostat column check failed\n{expected_columns_debug=}\n{actual_columns=}')
   exit(1)
  print('OK')