Viewing file:  plugin_scsi_host.py (3.08 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 SCSIHostPlugin(hotplug.Plugin):
"""
`scsi_host`::
Tunes options for SCSI hosts.
+
The plug-in sets Aggressive Link Power Management (ALPM) to the value specified
by the [option]`alpm` option. The option takes one of three values:
`min_power`, `medium_power` and `max_performance`.
+
NOTE: ALPM is only available on SATA controllers that use the Advanced
Host Controller Interface (AHCI).
+
.ALPM setting when extended periods of idle time are expected
====
----
[scsi_host]
alpm=min_power
----
====
"""
def __init__(self, *args, **kwargs):
super(SCSIHostPlugin, self).__init__(*args, **kwargs)
self._cmd = commands()
def _init_devices(self):
super(SCSIHostPlugin, self)._init_devices()
self._devices_supported = True
self._free_devices = set()
for device in self._hardware_inventory.get_devices("scsi"):
if self._device_is_supported(device):
self._free_devices.add(device.sys_name)
self._assigned_devices = set()
def _get_device_objects(self, devices):
return [self._hardware_inventory.get_device("scsi", x) for x in devices]
@classmethod
def _device_is_supported(cls, device):
return device.device_type == "scsi_host"
def _hardware_events_init(self):
self._hardware_inventory.subscribe(self, "scsi", 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):
super(SCSIHostPlugin, self)._hardware_events_callback(event, device)
def _added_device_apply_tuning(self, instance, device_name):
super(SCSIHostPlugin, self)._added_device_apply_tuning(instance, device_name)
def _removed_device_unapply_tuning(self, instance, device_name):
super(SCSIHostPlugin, self)._removed_device_unapply_tuning(instance, device_name)
@classmethod
def _get_config_options(cls):
return {
"alpm" : None,
}
def _instance_init(self, instance):
instance._has_static_tuning = True
instance._has_dynamic_tuning = False
def _instance_cleanup(self, instance):
pass
def _get_alpm_policy_file(self, device):
return os.path.join("/sys/class/scsi_host/", str(device), "link_power_management_policy")
@command_set("alpm", per_device = True)
def _set_alpm(self, policy, device, sim, remove):
if policy is None:
return None
policy_file = self._get_alpm_policy_file(device)
if not sim:
if os.path.exists(policy_file):
self._cmd.write_to_file(policy_file, policy, \
no_error = [errno.ENOENT] if remove else False)
else:
log.info("ALPM control file ('%s') not found, skipping ALPM setting for '%s'" % (policy_file, str(device)))
return None
return policy
@command_get("alpm")
def _get_alpm(self, device, ignore_missing=False):
policy_file = self._get_alpm_policy_file(device)
policy = self._cmd.read_file(policy_file, no_error = True).strip()
return policy if policy != "" else None
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