Current File : //usr/lib/python2.7/site-packages/tuned/plugins/plugin_scheduler.py
# code for cores isolation was inspired by Tuna implementation
# perf code was borrowed from kernel/tools/perf/python/twatch.py
# thanks to Arnaldo Carvalho de Melo <acme@redhat.com>
from . import base
from .decorators import *
import tuned.logs
import re
from subprocess import *
import threading
import perf
import select
import tuned.consts as consts
import procfs
import schedutils
from tuned.utils.commands import commands
import errno
log = tuned.logs.get()
class SchedulerParams(object):
def __init__(self, cmd, cmdline = None, scheduler = None,
priority = None, affinity = None):
self._cmd = cmd
self.cmdline = cmdline
self.scheduler = scheduler
self.priority = priority
self.affinity = affinity
@property
def affinity(self):
if self._affinity is None:
return None
else:
return self._cmd.bitmask2cpulist(self._affinity)
@affinity.setter
def affinity(self, value):
if value is None:
self._affinity = None
else:
self._affinity = self._cmd.cpulist2bitmask(value)
class IRQAffinities(object):
def __init__(self):
self.irqs = {}
self.default = None
class SchedulerPlugin(base.Plugin):
"""
Plugin for tuning of scheduler. Currently it can control scheduling
priorities of system threads (it is substitution for the rtctl tool).
"""
_dict_schedcfg2num = {
"f": schedutils.SCHED_FIFO,
"b": schedutils.SCHED_BATCH,
"r": schedutils.SCHED_RR,
"o": schedutils.SCHED_OTHER,
"i": schedutils.SCHED_IDLE,
}
def __init__(self, monitor_repository, storage_factory, hardware_inventory, device_matcher, device_matcher_udev, plugin_instance_factory, global_cfg, variables):
super(SchedulerPlugin, self).__init__(monitor_repository, storage_factory, hardware_inventory, device_matcher, device_matcher_udev, plugin_instance_factory, global_cfg, variables)
self._has_dynamic_options = True
self._daemon = consts.CFG_DEF_DAEMON
self._sleep_interval = int(consts.CFG_DEF_SLEEP_INTERVAL)
if global_cfg is not None:
self._daemon = global_cfg.get_bool(consts.CFG_DAEMON, consts.CFG_DEF_DAEMON)
self._sleep_interval = int(global_cfg.get(consts.CFG_SLEEP_INTERVAL, consts.CFG_DEF_SLEEP_INTERVAL))
self._cmd = commands()
# default is to whitelist all and blacklist none
self._ps_whitelist = ".*"
self._ps_blacklist = ""
self._cpus = perf.cpu_map()
self._scheduler_storage_key = self._storage_key(
command_name = "scheduler")
self._irq_storage_key = self._storage_key(
command_name = "irq")
def _instance_init(self, instance):
instance._has_dynamic_tuning = False
instance._has_static_tuning = True
# this is hack, runtime_tuning should be covered by dynamic_tuning configuration
# TODO: add per plugin dynamic tuning configuration and use dynamic_tuning configuration
# instead of runtime_tuning
instance._runtime_tuning = True
# FIXME: do we want to do this here?
# recover original values in case of crash
self._scheduler_original = self._storage.get(
self._scheduler_storage_key, {})
if len(self._scheduler_original) > 0:
log.info("recovering scheduling settings from previous run")
self._restore_ps_affinity()
self._scheduler_original = {}
self._storage.unset(self._scheduler_storage_key)
instance._scheduler = instance.options
for k in instance._scheduler:
instance._scheduler[k] = self._variables.expand(instance._scheduler[k])
if self._cmd.get_bool(instance._scheduler.get("runtime", 1)) == "0":
instance._runtime_tuning = False
instance._terminate = threading.Event()
if self._daemon and instance._runtime_tuning:
try:
instance._threads = perf.thread_map()
evsel = perf.evsel(type = perf.TYPE_SOFTWARE,
config = perf.COUNT_SW_DUMMY,
task = 1, comm = 1, mmap = 0, freq = 0,
wakeup_events = 1, watermark = 1,
sample_type = perf.SAMPLE_TID | perf.SAMPLE_CPU)
evsel.open(cpus = self._cpus, threads = instance._threads)
instance._evlist = perf.evlist(self._cpus, instance._threads)
instance._evlist.add(evsel)
instance._evlist.mmap()
# no perf
except:
instance._runtime_tuning = False
def _instance_cleanup(self, instance):
pass
@classmethod
def _get_config_options(cls):
return {
"isolated_cores": None,
"ps_whitelist": None,
"ps_blacklist": None,
}
# Raises OSError, IOError
def _get_cmdline(self, process):
if not isinstance(process, procfs.process):
pid = process
process = procfs.process(pid)
cmdline = procfs.process_cmdline(process)
if self._is_kthread(process):
cmdline = "[" + cmdline + "]"
return cmdline
# Raises OSError, IOError
def get_processes(self):
ps = procfs.pidstats()
ps.reload_threads()
processes = {}
for proc in ps.values():
try:
cmd = self._get_cmdline(proc)
pid = proc["pid"]
processes[pid] = cmd
if "threads" in proc:
for pid in proc["threads"].keys():
cmd = self._get_cmdline(proc)
processes[pid] = cmd
except (OSError, IOError) as e:
if e.errno == errno.ENOENT \
or e.errno == errno.ESRCH:
continue
else:
raise
return processes
# Raises OSError
# Raises SystemError with old (pre-0.4) python-schedutils
# instead of OSError
# If PID doesn't exist, errno == ESRCH
def _get_rt(self, pid):
scheduler = schedutils.get_scheduler(pid)
sched_str = schedutils.schedstr(scheduler)
priority = schedutils.get_priority(pid)
log.debug("Read scheduler policy '%s' and priority '%d' of PID '%d'"
% (sched_str, priority, pid))
return (scheduler, priority)
def _set_rt(self, pid, sched, prio):
sched_str = schedutils.schedstr(sched)
log.debug("Setting scheduler policy to '%s' and priority to '%d' of PID '%d'."
% (sched_str, prio, pid))
try:
prio_min = schedutils.get_priority_min(sched)
prio_max = schedutils.get_priority_max(sched)
if prio < prio_min or prio > prio_max:
log.error("Priority for %s must be in range %d - %d. '%d' was given."
% (sched_str, prio_min,
prio_max, prio))
# Workaround for old (pre-0.4) python-schedutils which raised
# SystemError instead of OSError
except (SystemError, OSError) as e:
log.error("Failed to get allowed priority range: %s"
% e)
try:
schedutils.set_scheduler(pid, sched, prio)
except (SystemError, OSError) as e:
if hasattr(e, "errno") and e.errno == errno.ESRCH:
log.debug("Failed to set scheduling parameters of PID %d, the task vanished."
% pid)
else:
log.error("Failed to set scheduling parameters of PID %d: %s"
% (pid, e))
# process is a procfs.process object
# Raises OSError, IOError
def _is_kthread(self, process):
return process["stat"]["flags"] & procfs.pidstat.PF_KTHREAD != 0
# Return codes:
# 0 - Affinity is fixed
# 1 - Affinity is changeable
# -1 - Task vanished
# -2 - Error
def _affinity_changeable(self, pid):
try:
process = procfs.process(pid)
if process["stat"].is_bound_to_cpu():
if process["stat"]["state"] == "Z":
log.debug("Affinity of zombie task with PID %d cannot be changed, the task's affinity mask is fixed."
% pid)
elif self._is_kthread(process):
log.debug("Affinity of kernel thread with PID %d cannot be changed, the task's affinity mask is fixed."
% pid)
else:
log.warn("Affinity of task with PID %d cannot be changed, the task's affinity mask is fixed."
% pid)
return 0
else:
return 1
except (OSError, IOError) as e:
if e.errno == errno.ENOENT or e.errno == errno.ESRCH:
log.debug("Failed to get task info for PID %d, the task vanished."
% pid)
return -1
else:
log.error("Failed to get task info for PID %d: %s"
% (pid, e))
return -2
except (AttributeError, KeyError) as e:
log.error("Failed to get task info for PID %d: %s"
% (pid, e))
return -2
def _store_orig_process_rt(self, pid, scheduler, priority):
try:
params = self._scheduler_original[pid]
except KeyError:
params = SchedulerParams(self._cmd)
self._scheduler_original[pid] = params
if params.scheduler is None and params.priority is None:
params.scheduler = scheduler
params.priority = priority
def _tune_process_rt(self, pid, sched, prio):
cont = True
if sched is None and prio is None:
return cont
try:
(prev_sched, prev_prio) = self._get_rt(pid)
if sched is None:
sched = prev_sched
self._set_rt(pid, sched, prio)
self._store_orig_process_rt(pid, prev_sched, prev_prio)
except (SystemError, OSError) as e:
if hasattr(e, "errno") and e.errno == errno.ESRCH:
log.debug("Failed to read scheduler policy of PID %d, the task vanished."
% pid)
if pid in self._scheduler_original:
del self._scheduler_original[pid]
cont = False
else:
log.error("Refusing to set scheduler and priority of PID %d, reading original scheduling parameters failed: %s"
% (pid, e))
return cont
def _store_orig_process_affinity(self, pid, affinity):
try:
params = self._scheduler_original[pid]
except KeyError:
params = SchedulerParams(self._cmd)
self._scheduler_original[pid] = params
if params.affinity is None:
params.affinity = affinity
def _tune_process_affinity(self, pid, affinity, intersect = False):
cont = True
if affinity is None:
return cont
try:
prev_affinity = self._get_affinity(pid)
if intersect:
affinity = self._get_intersect_affinity(
prev_affinity, affinity,
affinity)
self._set_affinity(pid, affinity)
self._store_orig_process_affinity(pid,
prev_affinity)
except (SystemError, OSError) as e:
if hasattr(e, "errno") and e.errno == errno.ESRCH:
log.debug("Failed to read affinity of PID %d, the task vanished."
% pid)
if pid in self._scheduler_original:
del self._scheduler_original[pid]
cont = False
else:
log.error("Refusing to set CPU affinity of PID %d, reading original affinity failed: %s"
% (pid, e))
return cont
#tune process and store previous values
def _tune_process(self, pid, cmd, sched, prio, affinity):
cont = self._tune_process_rt(pid, sched, prio)
if not cont:
return
cont = self._tune_process_affinity(pid, affinity)
if not cont or pid not in self._scheduler_original:
return
self._scheduler_original[pid].cmdline = cmd
def _convert_sched_params(self, str_scheduler, str_priority):
scheduler = self._dict_schedcfg2num.get(str_scheduler)
if scheduler is None and str_scheduler != "*":
log.error("Invalid scheduler: %s. Scheduler and priority will be ignored."
% str_scheduler)
return (None, None)
else:
try:
priority = int(str_priority)
except ValueError:
log.error("Invalid priority: %s. Scheduler and priority will be ignored."
% str_priority)
return (None, None)
return (scheduler, priority)
def _convert_affinity(self, str_affinity):
if str_affinity == "*":
affinity = None
else:
affinity = self._cmd.hex2cpulist(str_affinity)
if not affinity:
log.error("Invalid affinity: %s. It will be ignored."
% str_affinity)
affinity = None
return affinity
def _convert_sched_cfg(self, vals):
(rule_prio, scheduler, priority, affinity, regex) = vals
(scheduler, priority) = self._convert_sched_params(
scheduler, priority)
affinity = self._convert_affinity(affinity)
return (rule_prio, scheduler, priority, affinity, regex)
def _instance_apply_static(self, instance):
super(SchedulerPlugin, self)._instance_apply_static(instance)
try:
ps = self.get_processes()
except (OSError, IOError) as e:
log.error("error applying tuning, cannot get information about running processes: %s"
% e)
return
sched_cfg = [(option, str(value).split(":", 4)) for option, value in instance._scheduler.items()]
buf = [(option, self._convert_sched_cfg(vals))
for option, vals in sched_cfg
if re.match(r"group\.", option)
and len(vals) == 5]
sched_cfg = sorted(buf, key=lambda option_vals: option_vals[1][0])
sched_all = dict()
# for runtime tunning
instance._sched_lookup = {}
for option, (rule_prio, scheduler, priority, affinity, regex) \
in sched_cfg:
try:
r = re.compile(regex)
except re.error as e:
log.error("error compiling regular expression: '%s'" % str(regex))
continue
processes = [(pid, cmd) for pid, cmd in ps.items() if re.search(r, cmd) is not None]
#cmd - process name, option - group name
sched = dict([(pid, (cmd, option, scheduler, priority, affinity, regex))
for pid, cmd in processes])
sched_all.update(sched)
regex = str(regex).replace("(", r"\(")
regex = regex.replace(")", r"\)")
instance._sched_lookup[regex] = [scheduler, priority, affinity]
for pid, (cmd, option, scheduler, priority, affinity, regex) \
in sched_all.items():
self._tune_process(pid, cmd, scheduler,
priority, affinity)
self._storage.set(self._scheduler_storage_key,
self._scheduler_original)
if self._daemon and instance._runtime_tuning:
instance._thread = threading.Thread(target = self._thread_code, args = [instance])
instance._thread.start()
def _restore_ps_affinity(self):
try:
ps = self.get_processes()
except (OSError, IOError) as e:
log.error("error unapplying tuning, cannot get information about running processes: %s"
% e)
return
for pid, orig_params in self._scheduler_original.items():
# if command line for the pid didn't change, it's very probably the same process
if pid not in ps or ps[pid] != orig_params.cmdline:
continue
if orig_params.scheduler is not None \
and orig_params.priority is not None:
self._set_rt(pid, orig_params.scheduler,
orig_params.priority)
if orig_params.affinity is not None:
self._set_affinity(pid, orig_params.affinity)
self._scheduler_original = {}
self._storage.unset(self._scheduler_storage_key)
def _instance_unapply_static(self, instance, full_rollback = False):
super(SchedulerPlugin, self)._instance_unapply_static(instance, full_rollback)
if self._daemon and instance._runtime_tuning:
instance._terminate.set()
instance._thread.join()
self._restore_ps_affinity()
def _add_pid(self, instance, pid, r):
try:
cmd = self._get_cmdline(pid)
except (OSError, IOError) as e:
if e.errno == errno.ENOENT \
or e.errno == errno.ESRCH:
log.debug("Failed to get cmdline of PID %d, the task vanished."
% pid)
else:
log.error("Failed to get cmdline of PID %d: %s"
% (pid, e))
return
v = self._cmd.re_lookup(instance._sched_lookup, cmd, r)
if v is not None and not pid in self._scheduler_original:
log.debug("tuning new process '%s' with PID '%d' by '%s'" % (cmd, pid, str(v)))
(sched, prio, affinity) = v
self._tune_process(pid, cmd, sched, prio,
affinity)
self._storage.set(self._scheduler_storage_key,
self._scheduler_original)
def _remove_pid(self, instance, pid):
if pid in self._scheduler_original:
del self._scheduler_original[pid]
log.debug("removed PID %d from the rollback database" % pid)
self._storage.set(self._scheduler_storage_key,
self._scheduler_original)
def _thread_code(self, instance):
r = self._cmd.re_lookup_compile(instance._sched_lookup)
poll = select.poll()
# Store the file objects in a local variable so that they don't
# go out of scope too soon. This is a workaround for
# python3-perf bug rhbz#1659445.
fds = instance._evlist.get_pollfd()
for fd in fds:
poll.register(fd)
while not instance._terminate.is_set():
# timeout to poll in milliseconds
if len(poll.poll(self._sleep_interval * 1000)) > 0 and not instance._terminate.is_set():
read_events = True
while read_events:
read_events = False
for cpu in self._cpus:
event = instance._evlist.read_on_cpu(cpu)
if event:
read_events = True
if event.type == perf.RECORD_COMM:
self._add_pid(instance, int(event.tid), r)
elif event.type == perf.RECORD_EXIT:
self._remove_pid(instance, int(event.tid))
@command_custom("ps_whitelist", per_device = False)
def _ps_whitelist(self, enabling, value, verify, ignore_missing):
# currently unsupported
if verify:
return None
if enabling and value is not None:
self._ps_whitelist = "|".join(["(%s)" % v for v in re.split(r"(?<!\\);", str(value))])
@command_custom("ps_blacklist", per_device = False)
def _ps_blacklist(self, enabling, value, verify, ignore_missing):
# currently unsupported
if verify:
return None
if enabling and value is not None:
self._ps_blacklist = "|".join(["(%s)" % v for v in re.split(r"(?<!\\);", str(value))])
# Raises OSError
# Raises SystemError with old (pre-0.4) python-schedutils
# instead of OSError
# If PID doesn't exist, errno == ESRCH
def _get_affinity(self, pid):
res = schedutils.get_affinity(pid)
log.debug("Read affinity '%s' of PID %d" % (res, pid))
return res
def _set_affinity(self, pid, affinity):
log.debug("Setting CPU affinity of PID %d to '%s'." % (pid, affinity))
try:
schedutils.set_affinity(pid, affinity)
return True
# Workaround for old python-schedutils (pre-0.4) which
# incorrectly raised SystemError instead of OSError
except (SystemError, OSError) as e:
if hasattr(e, "errno") and e.errno == errno.ESRCH:
log.debug("Failed to set affinity of PID %d, the task vanished."
% pid)
else:
res = self._affinity_changeable(pid)
if res == 1 or res == -2:
log.error("Failed to set affinity of PID %d to '%s': %s"
% (pid, affinity, e))
return False
# returns intersection of affinity1 with affinity2, if intersection is empty it returns affinity3
def _get_intersect_affinity(self, affinity1, affinity2, affinity3):
aff = set(affinity1).intersection(set(affinity2))
if aff:
return list(aff)
return affinity3
def _set_all_obj_affinity(self, objs, affinity, threads = False):
psl = [v for v in objs if re.search(self._ps_whitelist,
self._get_stat_comm(v)) is not None]
if self._ps_blacklist != "":
psl = [v for v in psl if re.search(self._ps_blacklist,
self._get_stat_comm(v)) is None]
psd = dict([(v.pid, v) for v in psl])
for pid in psd:
try:
cmd = self._get_cmdline(psd[pid])
except (OSError, IOError) as e:
if e.errno == errno.ENOENT \
or e.errno == errno.ESRCH:
log.debug("Failed to get cmdline of PID %d, the task vanished."
% pid)
else:
log.error("Refusing to set affinity of PID %d, failed to get its cmdline: %s"
% (pid, e))
continue
cont = self._tune_process_affinity(pid, affinity,
intersect = True)
if not cont:
continue
if pid in self._scheduler_original:
self._scheduler_original[pid].cmdline = cmd
# process threads
if not threads and "threads" in psd[pid]:
self._set_all_obj_affinity(
psd[pid]["threads"].values(),
affinity, True)
def _get_stat_comm(self, o):
try:
return o["stat"]["comm"]
except (OSError, IOError, KeyError):
return ""
def _set_ps_affinity(self, affinity):
try:
ps = procfs.pidstats()
ps.reload_threads()
self._set_all_obj_affinity(ps.values(), affinity, False)
except (OSError, IOError) as e:
log.error("error applying tuning, cannot get information about running processes: %s"
% e)
def _set_irq_affinity(self, irq, affinity, restoring):
try:
affinity_hex = self._cmd.cpulist2hex(affinity)
log.debug("Setting SMP affinity of IRQ %s to '%s'"
% (irq, affinity_hex))
filename = "/proc/irq/%s/smp_affinity" % irq
with open(filename, "w") as f:
f.write(affinity_hex)
return True
except (OSError, IOError) as e:
# EIO is returned by
# kernel/irq/proc.c:write_irq_affinity() if changing
# the affinity is not supported
# (at least on kernels 3.10 and 4.18)
if hasattr(e, "errno") and e.errno == errno.EIO \
and not restoring:
log.debug("Setting SMP affinity of IRQ %s is not supported"
% irq)
else:
log.error("Failed to set SMP affinity of IRQ %s to '%s': %s"
% (irq, affinity_hex, e))
return False
def _set_default_irq_affinity(self, affinity):
try:
affinity_hex = self._cmd.cpulist2hex(affinity)
log.debug("Setting default SMP IRQ affinity to '%s'"
% affinity_hex)
with open("/proc/irq/default_smp_affinity", "w") as f:
f.write(affinity_hex)
except (OSError, IOError) as e:
log.error("Failed to set default SMP IRQ affinity to '%s': %s"
% (affinity_hex, e))
def _set_all_irq_affinity(self, affinity):
irq_original = IRQAffinities()
irqs = procfs.interrupts()
for irq in irqs.keys():
try:
prev_affinity = irqs[irq]["affinity"]
log.debug("Read affinity of IRQ '%s': '%s'"
% (irq, prev_affinity))
except KeyError:
continue
_affinity = self._get_intersect_affinity(prev_affinity, affinity, affinity)
if set(_affinity) == set(prev_affinity):
continue
if self._set_irq_affinity(irq, _affinity, False):
irq_original.irqs[irq] = prev_affinity
# default affinity
prev_affinity_hex = self._cmd.read_file("/proc/irq/default_smp_affinity")
prev_affinity = self._cmd.hex2cpulist(prev_affinity_hex)
_affinity = self._get_intersect_affinity(prev_affinity, affinity, affinity)
self._set_default_irq_affinity(_affinity)
irq_original.default = prev_affinity
self._storage.set(self._irq_storage_key, irq_original)
def _restore_all_irq_affinity(self):
irq_original = self._storage.get(self._irq_storage_key, None)
if irq_original is None:
return
for irq, affinity in irq_original.irqs.items():
self._set_irq_affinity(irq, affinity, True)
affinity = irq_original.default
self._set_default_irq_affinity(affinity)
self._storage.unset(self._irq_storage_key)
def _verify_irq_affinity(self, irq_description, correct_affinity,
current_affinity):
res = set(current_affinity).issubset(set(correct_affinity))
if res:
log.info(consts.STR_VERIFY_PROFILE_VALUE_OK
% (irq_description, current_affinity))
else:
log.error(consts.STR_VERIFY_PROFILE_VALUE_FAIL
% (irq_description, current_affinity,
correct_affinity))
return res
def _verify_all_irq_affinity(self, correct_affinity):
irqs = procfs.interrupts()
res = True
for irq in irqs.keys():
try:
current_affinity = irqs[irq]["affinity"]
log.debug("Read SMP affinity of IRQ '%s': '%s'"
% (irq, current_affinity))
irq_description = "SMP affinity of IRQ %s" % irq
if not self._verify_irq_affinity(
irq_description,
correct_affinity,
current_affinity):
res = False
except KeyError:
continue
current_affinity_hex = self._cmd.read_file(
"/proc/irq/default_smp_affinity")
current_affinity = self._cmd.hex2cpulist(current_affinity_hex)
if not self._verify_irq_affinity("default IRQ SMP affinity",
current_affinity, correct_affinity):
res = False
return res
@command_custom("isolated_cores", per_device = False, priority = 10)
def _isolated_cores(self, enabling, value, verify, ignore_missing):
affinity = None
if value is not None:
isolated = set(self._cmd.cpulist_unpack(value))
present = set(self._cpus)
if isolated.issubset(present):
affinity = list(present - isolated)
else:
str_cpus = ",".join([str(x) for x in self._cpus])
log.error("Invalid isolated_cores specified, '%s' does not match available cores '%s'"
% (value, str_cpus))
if (enabling or verify) and affinity is None:
return None
# currently only IRQ affinity verification is supported
if verify:
return self._verify_all_irq_affinity(affinity)
elif enabling:
self._set_ps_affinity(affinity)
self._set_all_irq_affinity(affinity)
else:
# Restoring processes' affinity is done in
# _instance_unapply_static()
self._restore_all_irq_affinity()
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