Viewing file:  plugin_sysctl.py (6.74 KB) -rw-r--r--
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import re
from . import base
from .decorators import *
import tuned.logs
from subprocess import *
from tuned.utils.commands import commands
import tuned.consts as consts
import errno
import os
log = tuned.logs.get()
DEPRECATED_SYSCTL_OPTIONS = [ "base_reachable_time", "retrans_time" ]
SYSCTL_CONFIG_DIRS = [ "/run/sysctl.d",
"/etc/sysctl.d" ]
class SysctlPlugin(base.Plugin):
"""
`sysctl`::
Sets various kernel parameters at runtime.
+
This plug-in is used for applying custom `sysctl` settings and should
only be used to change system settings that are not covered by other
*TuneD* plug-ins. If the settings are covered by other *TuneD* plug-ins,
use those plug-ins instead.
+
The syntax for this plug-in is
`_key_=_value_`, where
`_key_` is the same as the key name provided by the
`sysctl` utility.
+
.Adjusting the kernel runtime kernel.sched_min_granularity_ns value
====
----
[sysctl]
kernel.sched_min_granularity_ns=3000000
----
====
"""
def __init__(self, *args, **kwargs):
super(SysctlPlugin, self).__init__(*args, **kwargs)
self._has_dynamic_options = True
self._cmd = commands()
def _instance_init(self, instance):
instance._has_dynamic_tuning = False
instance._has_static_tuning = True
# FIXME: do we want to do this here?
# recover original values in case of crash
storage_key = self._storage_key(instance.name)
instance._sysctl_original = self._storage.get(storage_key, {})
if len(instance._sysctl_original) > 0:
log.info("recovering old sysctl settings from previous run")
self._instance_unapply_static(instance)
instance._sysctl_original = {}
self._storage.unset(storage_key)
instance._sysctl = instance.options
def _instance_cleanup(self, instance):
storage_key = self._storage_key(instance.name)
self._storage.unset(storage_key)
def _instance_apply_static(self, instance):
for option, value in list(instance._sysctl.items()):
original_value = self._read_sysctl(option)
if original_value is None:
log.error("sysctl option %s will not be set, failed to read the original value."
% option)
else:
new_value = self._variables.expand(
self._cmd.unquote(value))
new_value = self._process_assignment_modifiers(
new_value, original_value)
if new_value is not None:
instance._sysctl_original[option] = original_value
self._write_sysctl(option, new_value)
storage_key = self._storage_key(instance.name)
self._storage.set(storage_key, instance._sysctl_original)
if self._global_cfg.get_bool(consts.CFG_REAPPLY_SYSCTL, consts.CFG_DEF_REAPPLY_SYSCTL):
log.info("reapplying system sysctl")
self._apply_system_sysctl(instance._sysctl)
def _instance_verify_static(self, instance, ignore_missing, devices):
ret = True
# override, so always skip missing
ignore_missing = True
for option, value in list(instance._sysctl.items()):
curr_val = self._read_sysctl(option)
value = self._process_assignment_modifiers(self._variables.expand(value), curr_val)
if value is not None:
if self._verify_value(option, self._cmd.remove_ws(value), self._cmd.remove_ws(curr_val), ignore_missing) == False:
ret = False
return ret
def _instance_unapply_static(self, instance, rollback = consts.ROLLBACK_SOFT):
for option, value in list(instance._sysctl_original.items()):
self._write_sysctl(option, value)
def _apply_system_sysctl(self, instance_sysctl):
files = {}
for d in SYSCTL_CONFIG_DIRS:
try:
flist = os.listdir(d)
except OSError:
continue
for fname in flist:
if not fname.endswith(".conf"):
continue
if fname not in files:
files[fname] = d
for fname in sorted(files.keys()):
d = files[fname]
path = "%s/%s" % (d, fname)
self._apply_sysctl_config_file(path, instance_sysctl)
self._apply_sysctl_config_file("/etc/sysctl.conf", instance_sysctl)
def _apply_sysctl_config_file(self, path, instance_sysctl):
log.debug("Applying sysctl settings from file %s" % path)
try:
with open(path, "r") as f:
for lineno, line in enumerate(f, 1):
self._apply_sysctl_config_line(path, lineno, line, instance_sysctl)
log.debug("Finished applying sysctl settings from file %s"
% path)
except (OSError, IOError) as e:
if e.errno != errno.ENOENT:
log.error("Error reading sysctl settings from file %s: %s"
% (path, str(e)))
def _apply_sysctl_config_line(self, path, lineno, line, instance_sysctl):
line = line.strip()
if len(line) == 0 or line[0] == "#" or line[0] == ";":
return
tmp = line.split("=", 1)
if len(tmp) != 2:
log.error("Syntax error in file %s, line %d"
% (path, lineno))
return
option, value = tmp
option = option.strip()
if len(option) == 0:
log.error("Syntax error in file %s, line %d"
% (path, lineno))
return
value = value.strip()
if option in instance_sysctl:
instance_value = self._variables.expand(instance_sysctl[option])
if instance_value != value:
log.info("Overriding sysctl parameter '%s' from '%s' to '%s'"
% (option, instance_value, value))
self._write_sysctl(option, value, ignore_missing = True)
def _get_sysctl_path(self, option):
# The sysctl name in sysctl tool and in /proc/sys differs.
# All dots (.) in sysctl name are represented by /proc/sys
# directories and all slashes in the name (/) are converted
# to dots (.) in the /proc/sys filenames.
return "/proc/sys/%s" % self._cmd.tr(option, "./", "/.")
def _read_sysctl(self, option):
path = self._get_sysctl_path(option)
try:
with open(path, "r") as f:
line = ""
for i, line in enumerate(f):
if i > 0:
log.error("Failed to read sysctl parameter '%s', multi-line values are unsupported"
% option)
return None
value = line.strip()
log.debug("Value of sysctl parameter '%s' is '%s'"
% (option, value))
return value
except (OSError, IOError) as e:
if e.errno == errno.ENOENT:
log.error("Failed to read sysctl parameter '%s', the parameter does not exist"
% option)
else:
log.error("Failed to read sysctl parameter '%s': %s"
% (option, str(e)))
return None
def _write_sysctl(self, option, value, ignore_missing = False):
path = self._get_sysctl_path(option)
if os.path.basename(path) in DEPRECATED_SYSCTL_OPTIONS:
log.error("Refusing to set deprecated sysctl option %s"
% option)
return False
try:
log.debug("Setting sysctl parameter '%s' to '%s'"
% (option, value))
with open(path, "w") as f:
f.write(value)
return True
except (OSError, IOError) as e:
if e.errno == errno.ENOENT:
log_func = log.debug if ignore_missing else log.error
log_func("Failed to set sysctl parameter '%s' to '%s', the parameter does not exist"
% (option, value))
else:
log.error("Failed to set sysctl parameter '%s' to '%s': %s"
% (option, value, str(e)))
return False
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