def _get_cpu_model() -> pc.CPUModel:
if not os.path.exists('/dev/cpu/0/cpuid'):
log.warning(
'cannot detect cpu model (file /dev/cpu/0/cpuid does not exists!) '
'- returning unknown')
return pc.CPUModel.UNKNOWN
with SetEffectiveRootUid():
with open("/dev/cpu/0/cpuid", "rb") as f:
b = f.read(32)
eax = int(b[16]) + (int(b[17]) << 8) + (int(b[18]) << 16) + (
int(b[19]) << 24)
log.log(
logger.TRACE,
'16,17,18,19th bytes from /dev/cpu/0/cpuid: %02x %02x %02x %02x',
b[16], b[17], b[18], b[19])
model = (eax >> 4) & 0xF
family = (eax >> 8) & 0xF
extended_model = (eax >> 16) & 0xF
extended_family = (eax >> 20) & 0xFF
display_family = family
if family == 0xF:
display_family += extended_family
display_model = model
if family == 0x6 or family == 0xF:
display_model += (extended_model << 4)
if display_model in [0x4E, 0x5E, 0x55]:
return pc.CPUModel.SKYLAKE
elif display_model in [0x3D, 0x47, 0x4F, 0x56]:
return pc.CPUModel.BROADWELL
else:
return pc.CPUModel.UNKNOWN
def remove(self, mongroup_name):
"""Remove resctrl control directory or just mon_group if this is root or not last
container under control.
"""
# Try to clean itself if I'm the last mon_group and not root.
if self.name == RESCTRL_ROOT_NAME:
log.debug('resctrl: remove root')
dir_to_remove = self._get_mongroup_fullpath(mongroup_name)
else:
# For non root
# Am I last on the remove all.
if len(self.get_mon_groups()) == 1:
log.debug('resctrl: remove ctrl directory %r', self.name)
dir_to_remove = self.fullpath
else:
log.debug('resctrl: remove just mon_group %r in %r',
mongroup_name, self.name)
dir_to_remove = self._get_mongroup_fullpath(mongroup_name)
# Remove the mongroup directory if exists.
with SetEffectiveRootUid():
log.log(logger.TRACE, 'resctrl: rmdir(%r)', dir_to_remove)
if os.path.exists(dir_to_remove):
os.rmdir(dir_to_remove)
else:
log.debug("Directory: {} already removed. Ignoring!".format(
dir_to_remove))
def _add_pids_to_tasks_file(self, pids, tasks_filepath):
"""Writes pids to task file.
This function is susceptible to races caused by time that passes between read and write.
- causing errors like: ProcessLookupError
Error handling is based on edge cases available in:
https://github.com/torvalds/linux/blob/v4.20/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c#L676
and are mapped to python exceptions
https://github.com/python/cpython/blob/v3.6.8/Objects/exceptions.c#L2658
ESRCH -> ProcessLookupError
ENOENT -> FileNotFoundError
Important note: any writing/flushing error is going the reappear during closing,
that is why it is again wrapped by try:except (and why context manager is not used).
"""
if not pids:
return
log.log(logger.TRACE, 'resctrl: write(%s): number_of_pids=%r',
tasks_filepath, len(pids))
ftasks = None
try:
ftasks = open(tasks_filepath, 'w')
with SetEffectiveRootUid():
for pid in pids:
ftasks.write(pid)
ftasks.flush()
except ProcessLookupError:
log.warning(
'Could not write pid to resctrl (%r): '
'Process probably does not exist. ', tasks_filepath)
except FileNotFoundError:
log.error(
'Could not write pid to resctrl (%r): '
'rdt group was not found (moved/deleted - race detected).',
tasks_filepath)
except OSError as e:
if e.errno == errno.EINVAL:
# (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
log.error(
'Could not write pid to resctrl (%r): '
'Invalid argument %r.', tasks_filepath)
else:
log.error(
'Could not write pid to resctrl (%r): '
'Unexpected errno %r.', tasks_filepath, e.errno)
finally:
try:
# Try what we can to close the file but it is expected
# to fails because the wrong # data is waiting to be flushed
if ftasks is not None:
ftasks.close()
except (ProcessLookupError, FileNotFoundError, OSError):
log.warning('Could not close resctrl/tasks file - ignored!'
'(side-effect of previous warning!)')