1 # Copyright (c) 2012 The Chromium OS Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import hashlib, logging, multiprocessing, os, re, time 6 from autotest_lib.client.bin import test, utils 7 from autotest_lib.client.common_lib import error 8 from autotest_lib.client.cros import sys_power 9 10 SUSPEND_BURN_SECONDS = 10 11 RESUME_BURN_SECONDS = 5 12 MIN_CPU_USAGE = .95 13 14 PROC_STAT_CPU_FIELDS = ['user', 'nice', 'system', 'idle', 'iowait', 'irq', 15 'softirq', 'steal', 'guest', 'guest_nice'] 16 PROC_STAT_CPU_IDLE_FIELDS = ['idle', 'iowait'] 17 18 SYSFS_CPUQUIET_ENABLE = '/sys/devices/system/cpu/cpuquiet/tegra_cpuquiet/enable' 19 20 def cpu_stress(): 21 sha512_hash = open('/dev/urandom', 'r').read(64) 22 while True: 23 sha512_hash = hashlib.sha512(sha512_hash).digest() 24 25 26 def get_system_times(): 27 proc_stat = utils.read_file('/proc/stat') 28 for line in proc_stat.split('\n'): 29 if line.startswith('cpu '): 30 times = line[4:].strip().split(' ') 31 times = [int(jiffies) for jiffies in times] 32 return dict(zip(PROC_STAT_CPU_FIELDS, times)) 33 34 35 def get_avg_cpu_usage(pre_times, post_times): 36 diff_times = {} 37 38 for field in PROC_STAT_CPU_FIELDS: 39 diff_times[field] = post_times[field] - pre_times[field] 40 41 idle_time = sum(diff_times[field] for field in PROC_STAT_CPU_IDLE_FIELDS) 42 total_time = sum(diff_times[field] for field in PROC_STAT_CPU_FIELDS) 43 44 return float(total_time - idle_time) / total_time 45 46 47 def sleep_and_measure_cpu(sleep_seconds): 48 pre_times = get_system_times() 49 time.sleep(sleep_seconds) 50 post_times = get_system_times() 51 52 avg_cpu_usage = get_avg_cpu_usage(pre_times, post_times) 53 logging.info('average CPU utilization, last %ds: %s%%', 54 sleep_seconds, avg_cpu_usage * 100.) 55 return avg_cpu_usage 56 57 58 class power_HotCPUSuspend(test.test): 59 """Suspend the system with 100% CPU usage.""" 60 61 version = 1 62 63 def initialize(self): 64 # Store the setting if the system has CPUQuiet feature 65 if os.path.exists(SYSFS_CPUQUIET_ENABLE): 66 self.is_cpuquiet_enabled = utils.read_file(SYSFS_CPUQUIET_ENABLE) 67 utils.write_one_line(SYSFS_CPUQUIET_ENABLE, '0') 68 69 def run_once(self): 70 # create processs pool with enough workers to spin all CPUs 71 cpus = multiprocessing.cpu_count() 72 logging.info('found %d cpus', cpus) 73 workers = max(16, cpus * 2) 74 pool = multiprocessing.Pool(workers) 75 76 try: 77 # fill all CPUs with a spinning task 78 logging.info('starting %d workers', workers) 79 results = [pool.apply_async(cpu_stress) for _ in xrange(workers)] 80 81 # wait for things to settle 82 logging.info('spinning for %d seconds', SUSPEND_BURN_SECONDS) 83 if sleep_and_measure_cpu(SUSPEND_BURN_SECONDS) < MIN_CPU_USAGE: 84 # There should be no idle time accounted while we're spinning. 85 raise error.TestError('unexpected CPU idle time while spinning') 86 87 # go to suspend 88 sys_power.kernel_suspend(10) 89 90 # keep spinning after userland resumes 91 logging.info('spinning for %d more seconds', RESUME_BURN_SECONDS) 92 if sleep_and_measure_cpu(RESUME_BURN_SECONDS) < MIN_CPU_USAGE: 93 # There should be no idle time accounted while we're spinning. 94 raise error.TestError('unexpected CPU idle time after resume') 95 96 # check workers: if computation completed, something is wrong 97 for result in results: 98 if result.ready(): 99 logging.error('worker finished: %s', result.get()) 100 raise error.TestError('worker terminated!') 101 102 finally: 103 # kill off the workers 104 logging.info('killing %d workers', workers) 105 pool.terminate() 106 107 def cleanup(self): 108 # Restore the original setting if system has CPUQuiet feature 109 if os.path.exists(SYSFS_CPUQUIET_ENABLE): 110 utils.open_write_close( 111 SYSFS_CPUQUIET_ENABLE, self.is_cpuquiet_enabled) 112
