Current File : //usr/lib/python3.6/site-packages/tuned/plugins/plugin_systemd.py
from . import base
from .decorators import *
import tuned.logs
from . import exceptions
from tuned.utils.commands import commands
import tuned.consts as consts
import os
import re
log = tuned.logs.get()
class SystemdPlugin(base.Plugin):
"""
`systemd`::
Plug-in for tuning systemd options.
+
The [option]`cpu_affinity` option allows setting CPUAffinity in
`/etc/systemd/system.conf`. This configures the CPU affinity for the
service manager as well as the default CPU affinity for all forked
off processes. The option takes a comma-separated list of CPUs with
optional CPU ranges specified by the minus sign (`-`).
+
.Set the CPUAffinity for `systemd` to `0 1 2 3`
====
----
[systemd]
cpu_affinity=0-3
----
====
+
NOTE: These tunings are unloaded only on profile change followed by a reboot.
"""
def __init__(self, *args, **kwargs):
if not os.path.isfile(consts.SYSTEMD_SYSTEM_CONF_FILE):
raise exceptions.NotSupportedPluginException("Required systemd '%s' configuration file not found, disabling plugin." % consts.SYSTEMD_SYSTEM_CONF_FILE)
super(SystemdPlugin, self).__init__(*args, **kwargs)
self._cmd = commands()
def _instance_init(self, instance):
instance._has_dynamic_tuning = False
instance._has_static_tuning = True
def _instance_cleanup(self, instance):
pass
@classmethod
def _get_config_options(cls):
return {
"cpu_affinity": None,
}
def _get_keyval(self, conf, key):
if conf is not None:
mo = re.search(r"^\s*" + key + r"\s*=\s*(.*)$", conf, flags = re.MULTILINE)
if mo is not None and mo.lastindex == 1:
return mo.group(1)
return None
# add/replace key with the value
def _add_keyval(self, conf, key, val):
(conf_new, nsubs) = re.subn(r"^(\s*" + key + r"\s*=).*$", r"\g<1>" + str(val), conf, flags = re.MULTILINE)
if nsubs < 1:
try:
if conf[-1] != "\n":
conf += "\n"
except IndexError:
pass
conf += key + "=" + str(val) + "\n"
return conf
return conf_new
def _del_key(self, conf, key):
return re.sub(r"^\s*" + key + r"\s*=.*\n", "", conf, flags = re.MULTILINE)
def _read_systemd_system_conf(self):
systemd_system_conf = self._cmd.read_file(consts.SYSTEMD_SYSTEM_CONF_FILE, err_ret = None)
if systemd_system_conf is None:
log.error("error reading systemd configuration file")
return None
return systemd_system_conf
def _write_systemd_system_conf(self, conf):
tmpfile = consts.SYSTEMD_SYSTEM_CONF_FILE + consts.TMP_FILE_SUFFIX
if not self._cmd.write_to_file(tmpfile, conf):
log.error("error writing systemd configuration file")
self._cmd.unlink(tmpfile, no_error = True)
return False
# Atomic replace, this doesn't work on Windows (AFAIK there is no way on Windows how to do this
# atomically), but it's unlikely this code will run there
if not self._cmd.rename(tmpfile, consts.SYSTEMD_SYSTEM_CONF_FILE):
log.error("error replacing systemd configuration file '%s'" % consts.SYSTEMD_SYSTEM_CONF_FILE)
self._cmd.unlink(tmpfile, no_error = True)
return False
return True
def _get_storage_filename(self):
return os.path.join(consts.PERSISTENT_STORAGE_DIR, self.name)
def _remove_systemd_tuning(self):
conf = self._read_systemd_system_conf()
if (conf is not None):
fname = self._get_storage_filename()
cpu_affinity_saved = self._cmd.read_file(fname, err_ret = None, no_error = True)
self._cmd.unlink(fname)
if cpu_affinity_saved is None:
conf = self._del_key(conf, consts.SYSTEMD_CPUAFFINITY_VAR)
else:
conf = self._add_keyval(conf, consts.SYSTEMD_CPUAFFINITY_VAR, cpu_affinity_saved)
self._write_systemd_system_conf(conf)
def _instance_unapply_static(self, instance, rollback = consts.ROLLBACK_SOFT):
if rollback == consts.ROLLBACK_FULL:
log.info("removing '%s' systemd tuning previously added by TuneD" % consts.SYSTEMD_CPUAFFINITY_VAR)
self._remove_systemd_tuning()
log.console("you may need to manualy run 'dracut -f' to update the systemd configuration in initrd image")
# convert cpulist from systemd syntax to TuneD syntax and unpack it
def _cpulist_convert_unpack(self, cpulist):
if cpulist is None:
return ""
return " ".join(str(v) for v in self._cmd.cpulist_unpack(re.sub(r"\s+", r",", re.sub(r",\s+", r",", cpulist))))
@command_custom("cpu_affinity", per_device = False)
def _cmdline(self, enabling, value, verify, ignore_missing):
conf_affinity = None
conf_affinity_unpacked = None
v = self._cmd.unescape(self._variables.expand(self._cmd.unquote(value)))
v_unpacked = " ".join(str(v) for v in self._cmd.cpulist_unpack(v))
conf = self._read_systemd_system_conf()
if conf is not None:
conf_affinity = self._get_keyval(conf, consts.SYSTEMD_CPUAFFINITY_VAR)
conf_affinity_unpacked = self._cpulist_convert_unpack(conf_affinity)
if verify:
return self._verify_value("cpu_affinity", v_unpacked, conf_affinity_unpacked, ignore_missing)
if enabling:
fname = self._get_storage_filename()
cpu_affinity_saved = self._cmd.read_file(fname, err_ret = None, no_error = True)
if conf_affinity is not None and cpu_affinity_saved is None and v_unpacked != conf_affinity_unpacked:
self._cmd.write_to_file(fname, conf_affinity, makedir = True)
log.info("setting '%s' to '%s' in the '%s'" % (consts.SYSTEMD_CPUAFFINITY_VAR, v_unpacked, consts.SYSTEMD_SYSTEM_CONF_FILE))
self._write_systemd_system_conf(self._add_keyval(conf, consts.SYSTEMD_CPUAFFINITY_VAR, v_unpacked))
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