Current File : //lib/python3.6/site-packages/tuned/plugins/plugin_irqbalance.py
from . import base
from .decorators import command_custom
from tuned import consts
import tuned.logs
import errno
import perf
import re
log = tuned.logs.get()
class IrqbalancePlugin(base.Plugin):
"""
`irqbalance`::
Plug-in for irqbalance settings management. The plug-in
configures CPUs which should be skipped when rebalancing IRQs in
`/etc/sysconfig/irqbalance`. It then restarts irqbalance if and
only if it was previously running.
+
The banned/skipped CPUs are specified as a CPU list via the
[option]`banned_cpus` option.
+
.Skip CPUs 2,4 and 9-13 when rebalancing IRQs
====
----
[irqbalance]
banned_cpus=2,4,9-13
----
====
"""
def __init__(self, *args, **kwargs):
super(IrqbalancePlugin, self).__init__(*args, **kwargs)
self._cpus = perf.cpu_map()
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 {
"banned_cpus": None,
}
def _read_irqbalance_sysconfig(self):
try:
with open(consts.IRQBALANCE_SYSCONFIG_FILE, "r") as f:
return f.read()
except IOError as e:
if e.errno == errno.ENOENT:
log.warn("irqbalance sysconfig file is missing. Is irqbalance installed?")
else:
log.error("Failed to read irqbalance sysconfig file: %s" % e)
return None
def _write_irqbalance_sysconfig(self, content):
try:
with open(consts.IRQBALANCE_SYSCONFIG_FILE, "w") as f:
f.write(content)
return True
except IOError as e:
log.error("Failed to write irqbalance sysconfig file: %s" % e)
return False
def _write_banned_cpus(self, sysconfig, banned_cpumask):
return sysconfig + "IRQBALANCE_BANNED_CPUS=%s\n" % banned_cpumask
def _clear_banned_cpus(self, sysconfig):
lines = []
for line in sysconfig.split("\n"):
if not re.match(r"\s*IRQBALANCE_BANNED_CPUS=", line):
lines.append(line)
return "\n".join(lines)
def _restart_irqbalance(self):
# Exit code 5 means unit not found (see 'EXIT_NOTINSTALLED' in
# systemd.exec(5))
retcode, out = self._cmd.execute(
["systemctl", "try-restart", "irqbalance"],
no_errors=[5])
if retcode != 0:
log.warn("Failed to restart irqbalance. Is it installed?")
def _set_banned_cpus(self, banned_cpumask):
content = self._read_irqbalance_sysconfig()
if content is None:
return
content = self._clear_banned_cpus(content)
content = self._write_banned_cpus(content, banned_cpumask)
if self._write_irqbalance_sysconfig(content):
self._restart_irqbalance()
def _restore_banned_cpus(self):
content = self._read_irqbalance_sysconfig()
if content is None:
return
content = self._clear_banned_cpus(content)
if self._write_irqbalance_sysconfig(content):
self._restart_irqbalance()
@command_custom("banned_cpus", per_device=False)
def _banned_cpus(self, enabling, value, verify, ignore_missing):
banned_cpumask = None
if value is not None:
banned = set(self._cmd.cpulist_unpack(value))
present = set(self._cpus)
if banned.issubset(present):
banned_cpumask = self._cmd.cpulist2hex(list(banned))
else:
str_cpus = ",".join([str(x) for x in self._cpus])
log.error("Invalid banned_cpus specified, '%s' does not match available cores '%s'"
% (value, str_cpus))
if (enabling or verify) and banned_cpumask is None:
return None
if verify:
# Verification is currently not supported
return None
elif enabling:
self._set_banned_cpus(banned_cpumask)
else:
self._restore_banned_cpus()
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