def is_rotational_device(device):
"""Returns whether the given device is a rotational device.
Args:
device: The device.
Returns:
True if is a rotational device, else False.
"""
printf('Checking whether device {} is a rotational device'.format(device),
print_type=PrintType.DEBUG_LOG)
device_name = match_regex(device, 'device_name')
if not device_name:
return False
out, rc = run_command(
'cat /sys/block/{}/queue/rotational'.format(device_name))
if rc != 0:
return False
if int(out) == 1:
printf('Device {} is a rotational device'.format(device),
print_type=PrintType.DEBUG_LOG)
else:
printf('Device {} is not a rotational device'.format(device),
print_type=PrintType.DEBUG_LOG)
return int(out) == 1
def get_device_scheduler(device):
"""Returns the current scheduler for the device.
Args:
device: The device.
Returns:
The current scheduler.
"""
printf('Retrieving schedulers for device {}'.format(device),
print_type=PrintType.DEBUG_LOG)
device_name = match_regex(device, 'device_name')
out, rc = run_command(
'cat /sys/block/{}/queue/scheduler'.format(device_name))
if rc != 0:
printf('Unable to find schedulers for device',
print_type=PrintType.ERROR_LOG)
return []
l, r = out.index('['), out.index(']')
ret = out[l + 1:r]
printf('Found the current scheduler for device {}: '
'{}'.format(device, ret),
print_type=PrintType.DEBUG_LOG)
return ret
def get_schedulers_for_device(device):
"""Returns a list of available schedulers for a given device.
Args:
device: The device.
Returns:
A list of schedulers.
"""
printf('Retrieving schedulers for device {}'.format(device),
print_type=PrintType.DEBUG_LOG)
device_name = match_regex(device, 'device_name')
out, rc = run_command(
'cat /sys/block/{}/queue/scheduler'.format(device_name))
if rc != 0:
printf('Unable to find schedulers for device',
print_type=PrintType.ERROR_LOG)
return []
ret = out.strip().replace('[', '').replace(']', '')
printf('Found the following schedulers for device {}: '
'{}'.format(device, ret),
print_type=PrintType.DEBUG_LOG)
return ret.split()
def _try_process(self, job_type, file, device, scheduler, enable_blktrace):
"""Attempts to process a job with retrying if failure.
Args:
job_type: The job type.
file: The input file.
device: The device to execute on.
scheduler: The scheduler to execute with.
enable_blktrace: Whether blktrace is enabled.
Returns:
The output of processing the job.
Raises:
RetryCountExceededError: If job fails and retry counts are exceeded.
"""
retry_count = SettingsManager.get('retry_count')
for retry in range(retry_count):
if retry != 0:
printf('Retrying job...', print_type=PrintType.DEBUG_LOG)
job = job_type(file, device, scheduler)
try:
ret = job.process(enable_blktrace)
if SettingsManager.get('cleanup_files'):
device_name = match_regex(device, 'device_name')
files = get_formatter('cleanup_blktrace').format(
device_name)
cleanup_files(files)
return ret
except (JobExecutionError, OutputParsingError) as err:
printf('Unable to run job \n{}'.format(err),
print_type=PrintType.ERROR_LOG)
raise RetryCountExceededError(
'Unable to run job, exceeded retry counts')
def change_scheduler(device, scheduler):
"""Changes the I/O scheduler for the given device.
Args:
device: The device.
scheduler: The I/O scheduler.
Returns:
True if successful, else False.
"""
printf('Changing scheduler for device {} to {}'.format(device, scheduler),
print_type=PrintType.DEBUG_LOG)
command = 'bash -c "echo {} > /sys/block/{}/queue/scheduler"' \
.format(scheduler, match_regex(device, 'device_name'))
_, rc = run_command(command)
if rc != 0:
raise SchedulerChangeError(
'Unable to change scheduler to {} for device {}'.format(
scheduler, device))
def change_nomerges(device, nomerges):
"""Changes the nomerges setting for the given device.
Args:
device: The device.
nomerges: The nomerges setting.
Returns:
True if successful, else False.
"""
printf('Changing nomerges for device {} to {}'.format(device, nomerges),
print_type=PrintType.DEBUG_LOG)
command = 'bash -c "echo {} > /sys/block/{}/queue/nomerges"' \
.format(nomerges, match_regex(device, 'device_name'))
_, rc = run_command(command)
if rc != 0:
raise DeviceSettingChangeError(
'Unable to change nomerges to {} for device {}'.format(
nomerges, device))
def get_device_nomerges(device):
"""Returns the current nomerges for the device.
Args:
device: The device.
Returns:
The current nomerges setting.
"""
printf('Retrieving nomerges for device {}'.format(device),
print_type=PrintType.DEBUG_LOG)
device_name = match_regex(device, 'device_name')
out, rc = run_command(
'cat /sys/block/{}/queue/nomerges'.format(device_name))
if rc != 0:
printf('Unable to find nomerges for device',
print_type=PrintType.ERROR_LOG)
return []
return int(out)
def _interpolate_text(self, text, device, scheduler, sp):
"""Interpolates text.
Args:
text: The text to interpolate.
device: The device.
scheduler: The scheduler.
sp: The permutated template settings.
Returns:
The interpolated text.
"""
tf = get_formatter('template')
device_name = match_regex(device, 'device_name')
text = text.replace(tf.format('device'), device)
text = text.replace(tf.format('device_name'), device_name)
text = text.replace(tf.format('scheduler'), scheduler)
for setting in sp:
name, value = setting.split('=')
text = text.replace(tf.format(name), value)
return text