Viewing file:  plugin_disk.py (13.77 KB) -rw-r--r--
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import errno
from . import hotplug
from .decorators import *
import tuned.logs
import tuned.consts as consts
from tuned.utils.commands import commands
import os
import re
log = tuned.logs.get()
class DiskPlugin(hotplug.Plugin):
"""
Plugin for tuning options of disks.
"""
def __init__(self, *args, **kwargs):
super(DiskPlugin, self).__init__(*args, **kwargs)
self._power_levels = [254, 225, 195, 165, 145, 125, 105, 85, 70, 55, 30, 20]
self._spindown_levels = [0, 250, 230, 210, 190, 170, 150, 130, 110, 90, 70, 60]
self._levels = len(self._power_levels)
self._level_steps = 6
self._load_smallest = 0.01
self._cmd = commands()
def _init_devices(self):
super(DiskPlugin, self)._init_devices()
self._devices_supported = True
self._use_hdparm = True
self._free_devices = set()
self._hdparm_apm_devices = set()
for device in self._hardware_inventory.get_devices("block"):
if self._device_is_supported(device):
self._free_devices.add(device.sys_name)
if self._use_hdparm and self._is_hdparm_apm_supported(device.sys_name):
self._hdparm_apm_devices.add(device.sys_name)
self._assigned_devices = set()
def _get_device_objects(self, devices):
return [self._hardware_inventory.get_device("block", x) for x in devices]
def _is_hdparm_apm_supported(self, device):
(rc, out, err_msg) = self._cmd.execute(["hdparm", "-C", "/dev/%s" % device], \
no_errors = [errno.ENOENT], return_err=True)
if rc == -errno.ENOENT:
log.warn("hdparm command not found, ignoring for other devices")
self._use_hdparm = False
return False
elif rc:
log.info("Device '%s' not supported by hdparm" % device)
log.debug("(rc: %s, msg: '%s')" % (rc, err_msg))
return False
elif "unknown" in out:
log.info("Driver for device '%s' does not support apm command" % device)
return False
return True
@classmethod
def _device_is_supported(cls, device):
return device.device_type == "disk" and \
device.attributes.get("removable", None) == b"0" and \
(device.parent is None or \
device.parent.subsystem in ["scsi", "virtio", "xen", "nvme"])
def _hardware_events_init(self):
self._hardware_inventory.subscribe(self, "block", self._hardware_events_callback)
def _hardware_events_cleanup(self):
self._hardware_inventory.unsubscribe(self)
def _hardware_events_callback(self, event, device):
if self._device_is_supported(device) or event == "remove":
super(DiskPlugin, self)._hardware_events_callback(event, device)
def _added_device_apply_tuning(self, instance, device_name):
if instance._load_monitor is not None:
instance._load_monitor.add_device(device_name)
super(DiskPlugin, self)._added_device_apply_tuning(instance, device_name)
def _removed_device_unapply_tuning(self, instance, device_name):
if instance._load_monitor is not None:
instance._load_monitor.remove_device(device_name)
super(DiskPlugin, self)._removed_device_unapply_tuning(instance, device_name)
@classmethod
def _get_config_options(cls):
return {
"dynamic" : True, # FIXME: do we want this default?
"elevator" : None,
"apm" : None,
"spindown" : None,
"readahead" : None,
"readahead_multiply" : None,
"scheduler_quantum" : None,
}
@classmethod
def _get_config_options_used_by_dynamic(cls):
return [
"apm",
"spindown",
]
def _instance_init(self, instance):
instance._has_static_tuning = True
self._apm_errcnt = 0
self._spindown_errcnt = 0
if self._option_bool(instance.options["dynamic"]):
instance._has_dynamic_tuning = True
instance._load_monitor = \
self._monitors_repository.create(
"disk", instance.assigned_devices)
instance._device_idle = {}
instance._stats = {}
instance._idle = {}
instance._spindown_change_delayed = {}
else:
instance._has_dynamic_tuning = False
instance._load_monitor = None
def _instance_cleanup(self, instance):
if instance._load_monitor is not None:
self._monitors_repository.delete(instance._load_monitor)
instance._load_monitor = None
def _update_errcnt(self, rc, spindown):
if spindown:
s = "spindown"
cnt = self._spindown_errcnt
else:
s = "apm"
cnt = self._apm_errcnt
if cnt >= consts.ERROR_THRESHOLD:
return
if rc == 0:
cnt = 0
elif rc == -errno.ENOENT:
self._spindown_errcnt = self._apm_errcnt = consts.ERROR_THRESHOLD + 1
log.warn("hdparm command not found, ignoring future set_apm / set_spindown commands")
return
else:
cnt += 1
if cnt == consts.ERROR_THRESHOLD:
log.info("disabling set_%s command: too many consecutive errors" % s)
if spindown:
self._spindown_errcnt = cnt
else:
self._apm_errcnt = cnt
def _change_spindown(self, instance, device, new_spindown_level):
log.debug("changing spindown to %d" % new_spindown_level)
(rc, out) = self._cmd.execute(["hdparm", "-S%d" % new_spindown_level, "/dev/%s" % device], no_errors = [errno.ENOENT])
self._update_errcnt(rc, True)
instance._spindown_change_delayed[device] = False
def _drive_spinning(self, device):
(rc, out) = self._cmd.execute(["hdparm", "-C", "/dev/%s" % device], no_errors = [errno.ENOENT])
return not "standby" in out and not "sleeping" in out
def _instance_update_dynamic(self, instance, device):
if not device in self._hdparm_apm_devices:
return
load = instance._load_monitor.get_device_load(device)
if load is None:
return
if not device in instance._stats:
self._init_stats_and_idle(instance, device)
self._update_stats(instance, device, load)
self._update_idle(instance, device)
stats = instance._stats[device]
idle = instance._idle[device]
# level change decision
if idle["level"] + 1 < self._levels and idle["read"] >= self._level_steps and idle["write"] >= self._level_steps:
level_change = 1
elif idle["level"] > 0 and (idle["read"] == 0 or idle["write"] == 0):
level_change = -1
else:
level_change = 0
# change level if decided
if level_change != 0:
idle["level"] += level_change
new_power_level = self._power_levels[idle["level"]]
new_spindown_level = self._spindown_levels[idle["level"]]
log.debug("tuning level changed to %d" % idle["level"])
if self._spindown_errcnt < consts.ERROR_THRESHOLD:
if not self._drive_spinning(device) and level_change > 0:
log.debug("delaying spindown change to %d, drive has already spun down" % new_spindown_level)
instance._spindown_change_delayed[device] = True
else:
self._change_spindown(instance, device, new_spindown_level)
if self._apm_errcnt < consts.ERROR_THRESHOLD:
log.debug("changing APM_level to %d" % new_power_level)
(rc, out) = self._cmd.execute(["hdparm", "-B%d" % new_power_level, "/dev/%s" % device], no_errors = [errno.ENOENT])
self._update_errcnt(rc, False)
elif instance._spindown_change_delayed[device] and self._drive_spinning(device):
new_spindown_level = self._spindown_levels[idle["level"]]
self._change_spindown(instance, device, new_spindown_level)
log.debug("%s load: read %0.2f, write %0.2f" % (device, stats["read"], stats["write"]))
log.debug("%s idle: read %d, write %d, level %d" % (device, idle["read"], idle["write"], idle["level"]))
def _init_stats_and_idle(self, instance, device):
instance._stats[device] = { "new": 11 * [0], "old": 11 * [0], "max": 11 * [1] }
instance._idle[device] = { "level": 0, "read": 0, "write": 0 }
instance._spindown_change_delayed[device] = False
def _update_stats(self, instance, device, new_load):
instance._stats[device]["old"] = old_load = instance._stats[device]["new"]
instance._stats[device]["new"] = new_load
# load difference
diff = [new_old[0] - new_old[1] for new_old in zip(new_load, old_load)]
instance._stats[device]["diff"] = diff
# adapt maximum expected load if the difference is higher
old_max_load = instance._stats[device]["max"]
max_load = [max(pair) for pair in zip(old_max_load, diff)]
instance._stats[device]["max"] = max_load
# read/write ratio
instance._stats[device]["read"] = float(diff[1]) / float(max_load[1])
instance._stats[device]["write"] = float(diff[5]) / float(max_load[5])
def _update_idle(self, instance, device):
# increase counter if there is no load, otherwise reset the counter
for operation in ["read", "write"]:
if instance._stats[device][operation] < self._load_smallest:
instance._idle[device][operation] += 1
else:
instance._idle[device][operation] = 0
def _instance_apply_dynamic(self, instance, device):
# At the moment we support dynamic tuning just for devices compatible with hdparm apm commands
# If in future will be added new functionality not connected to this command,
# it is needed to change it here
if device not in self._hdparm_apm_devices:
log.info("There is no dynamic tuning available for device '%s' at time" % device)
else:
super(DiskPlugin, self)._instance_apply_dynamic(*args, **kwargs)
def _instance_unapply_dynamic(self, instance, device):
pass
def _sysfs_path(self, device, suffix, prefix = "/sys/block/"):
if "/" in device:
dev = os.path.join(prefix, device.replace("/", "!"), suffix)
if os.path.exists(dev):
return dev
return os.path.join(prefix, device, suffix)
def _elevator_file(self, device):
return self._sysfs_path(device, "queue/scheduler")
@command_set("elevator", per_device=True)
def _set_elevator(self, value, device, sim):
sys_file = self._elevator_file(device)
if not sim:
self._cmd.write_to_file(sys_file, value)
return value
@command_get("elevator")
def _get_elevator(self, device, ignore_missing=False):
sys_file = self._elevator_file(device)
# example of scheduler file content:
# noop deadline [cfq]
return self._cmd.get_active_option(self._cmd.read_file(sys_file, no_error=ignore_missing))
@command_set("apm", per_device=True)
def _set_apm(self, value, device, sim):
if device not in self._hdparm_apm_devices:
if not sim:
log.info("apm option is not supported for device '%s'" % device)
return None
else:
return str(value)
if self._apm_errcnt < consts.ERROR_THRESHOLD:
if not sim:
(rc, out) = self._cmd.execute(["hdparm", "-B", str(value), "/dev/" + device], no_errors = [errno.ENOENT])
self._update_errcnt(rc, False)
return str(value)
else:
return None
@command_get("apm")
def _get_apm(self, device, ignore_missing=False):
if device not in self._hdparm_apm_devices:
if not ignore_missing:
log.info("apm option is not supported for device '%s'" % device)
return None
value = None
err = False
(rc, out) = self._cmd.execute(["hdparm", "-B", "/dev/" + device], no_errors = [errno.ENOENT])
if rc == -errno.ENOENT:
return None
elif rc != 0:
err = True
else:
m = re.match(r".*=\s*(\d+).*", out, re.S)
if m:
try:
value = int(m.group(1))
except ValueError:
err = True
if err:
log.error("could not get current APM settings for device '%s'" % device)
return value
@command_set("spindown", per_device=True)
def _set_spindown(self, value, device, sim):
if device not in self._hdparm_apm_devices:
if not sim:
log.info("spindown option is not supported for device '%s'" % device)
return None
else:
return str(value)
if self._spindown_errcnt < consts.ERROR_THRESHOLD:
if not sim:
(rc, out) = self._cmd.execute(["hdparm", "-S", str(value), "/dev/" + device], no_errors = [errno.ENOENT])
self._update_errcnt(rc, True)
return str(value)
else:
return None
@command_get("spindown")
def _get_spindown(self, device, ignore_missing=False):
if device not in self._hdparm_apm_devices:
if not ignore_missing:
log.info("spindown option is not supported for device '%s'" % device)
return None
# There's no way how to get current/old spindown value, hardcoding vendor specific 253
return 253
def _readahead_file(self, device):
return self._sysfs_path(device, "queue/read_ahead_kb")
def _parse_ra(self, value):
val = str(value).split(None, 1)
v = int(val[0])
if len(val) > 1 and val[1][0] == "s":
# v *= 512 / 1024
v /= 2
return v
@command_set("readahead", per_device=True)
def _set_readahead(self, value, device, sim):
sys_file = self._readahead_file(device)
val = self._parse_ra(value)
if not sim:
self._cmd.write_to_file(sys_file, "%d" % val)
return val
@command_get("readahead")
def _get_readahead(self, device, ignore_missing=False):
sys_file = self._readahead_file(device)
value = self._cmd.read_file(sys_file, no_error=ignore_missing).strip()
if len(value) == 0:
return None
return int(value)
@command_custom("readahead_multiply", per_device=True)
def _multiply_readahead(self, enabling, multiplier, device, verify, ignore_missing):
if verify:
return None
storage_key = self._storage_key(
command_name = "readahead_multiply",
device_name = device)
if enabling:
old_readahead = self._get_readahead(device)
if old_readahead is None:
return
new_readahead = int(float(multiplier) * old_readahead)
self._storage.set(storage_key, old_readahead)
self._set_readahead(new_readahead, device, False)
else:
old_readahead = self._storage.get(storage_key)
if old_readahead is None:
return
self._set_readahead(old_readahead, device, False)
self._storage.unset(storage_key)
def _scheduler_quantum_file(self, device):
return self._sysfs_path(device, "queue/iosched/quantum")
@command_set("scheduler_quantum", per_device=True)
def _set_scheduler_quantum(self, value, device, sim):
sys_file = self._scheduler_quantum_file(device)
if not sim:
self._cmd.write_to_file(sys_file, "%d" % int(value))
return value
@command_get("scheduler_quantum")
def _get_scheduler_quantum(self, device, ignore_missing=False):
sys_file = self._scheduler_quantum_file(device)
value = self._cmd.read_file(sys_file, no_error=ignore_missing).strip()
if len(value) == 0:
if not ignore_missing:
log.info("disk_scheduler_quantum option is not supported for device '%s'" % device)
return None
return int(value)
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