name : 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()