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Editing: plugin_sysctl.py
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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