Merge pull request #323 from CZerta/scheduler_os_interface

Changes to scheduler plugin to support os interface instead of schedutils in newer python versions.

tuned.spec

@@ -69,7 +69,10 @@ BuildRequires: %{_py}-mock
 BuildRequires: %{_py}-configobj
 BuildRequires: %{_py}-decorator, %{_py}-pyudev
 Requires: %{_py}-decorator, %{_py}-pyudev, %{_py}-configobj
-Requires: %{_py}-schedutils, %{_py}-linux-procfs, %{_py}-perf
+Requires: %{_py}-linux-procfs, %{_py}-perf
+%if %{without python3}
+Requires: %{_py}-schedutils
+%endif
 # requires for packages with inconsistent python2/3 names
 %if %{with python3}
 # BuildRequires for 'make test'

tuned/plugins/plugin_scheduler.py

@@ -12,12 +12,16 @@ import perf
 import select
 import tuned.consts as consts
 import procfs
-import schedutils
 from tuned.utils.commands import commands
 import errno
 import os
 import collections
 import math
+# Check existence of scheduler API in os module
+try:
+	os.SCHED_FIFO
+except AttributeError:
+	import schedutils
 
 log = tuned.logs.get()
 
@@ -52,20 +56,90 @@ class IRQAffinities(object):
 		# IRQs that don't support changing CPU affinity:
 		self.unchangeable = []
 
+class SchedulerUtils(object):
+	"""
+	Class encapsulating scheduler implementation in os module
+	"""
+
+	_dict_schedcfg2schedconst = {
+		"f": "SCHED_FIFO",
+		"b": "SCHED_BATCH",
+		"r": "SCHED_RR",
+		"o": "SCHED_OTHER",
+		"i": "SCHED_IDLE",
+	}
+
+	def __init__(self):
+		# {"f": os.SCHED_FIFO...}
+		self._dict_schedcfg2num = dict((k, getattr(os, name)) for k, name in self._dict_schedcfg2schedconst.items())
+		# { os.SCHED_FIFO: "SCHED_FIFO"... }
+		self._dict_num2schedconst = dict((getattr(os, name), name) for name in self._dict_schedcfg2schedconst.values())
+
+	def sched_cfg_to_num(self, str_scheduler):
+		return self._dict_schedcfg2num.get(str_scheduler)
+
+	# Reimplementation of schedstr from schedutils for logging purposes
+	def sched_num_to_const(self, scheduler):
+		return self._dict_num2schedconst.get(scheduler)
+
+	def get_scheduler(self, pid):
+		return os.sched_getscheduler(pid)
+
+	def set_scheduler(self, pid, sched, prio):
+		os.sched_setscheduler(pid, sched, os.sched_param(prio))
+
+	def get_affinity(self, pid):
+		return os.sched_getaffinity(pid)
+
+	def set_affinity(self, pid, affinity):
+		os.sched_setaffinity(pid, affinity)
+
+	def get_priority(self, pid):
+		return os.sched_getparam(pid).sched_priority
+
+	def get_priority_min(self, sched):
+		return os.sched_get_priority_min(sched)
+
+	def get_priority_max(self, sched):
+		return os.sched_get_priority_max(sched)
+
+class SchedulerUtilsSchedutils(SchedulerUtils):
+	"""
+	Class encapsulating scheduler implementation in schedutils module
+	"""
+	def __init__(self):
+		# { "f": schedutils.SCHED_FIFO... }
+		self._dict_schedcfg2num = dict((k, getattr(schedutils, name)) for k, name in self._dict_schedcfg2schedconst.items())
+		# { schedutils.SCHED_FIFO: "SCHED_FIFO"... }
+		self._dict_num2schedconst = dict((getattr(schedutils, name), name) for name in self._dict_schedcfg2schedconst.values())
+
+	def get_scheduler(self, pid):
+		return schedutils.get_scheduler(pid)
+
+	def set_scheduler(self, pid, sched, prio):
+		schedutils.set_scheduler(pid, sched, prio)
+
+	def get_affinity(self, pid):
+		return schedutils.get_affinity(pid)
+
+	def set_affinity(self, pid, affinity):
+		schedutils.set_affinity(pid, affinity)
+
+	def get_priority(self, pid):
+		return schedutils.get_priority(pid)
+
+	def get_priority_min(self, sched):
+		return schedutils.get_priority_min(sched)
+
+	def get_priority_max(self, sched):
+		return schedutils.get_priority_max(sched)
+
 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
@@ -83,6 +157,10 @@ class SchedulerPlugin(base.Plugin):
 				command_name = "scheduler")
 		self._irq_storage_key = self._storage_key(
 				command_name = "irq")
+		try:
+			self._scheduler_utils = SchedulerUtils()
+		except AttributeError:
+			self._scheduler_utils = SchedulerUtilsSchedutils()
 
 	def _calc_mmap_pages(self, mmap_pages):
 		if mmap_pages is None:
@@ -216,20 +294,20 @@ class SchedulerPlugin(base.Plugin):
 	# 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)
+		scheduler = self._scheduler_utils.get_scheduler(pid)
+		sched_str = self._scheduler_utils.sched_num_to_const(scheduler)
+		priority = self._scheduler_utils.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)
+		sched_str = self._scheduler_utils.sched_num_to_const(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)
+			prio_min = self._scheduler_utils.get_priority_min(sched)
+			prio_max = self._scheduler_utils.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,
@@ -240,7 +318,7 @@ class SchedulerPlugin(base.Plugin):
 			log.error("Failed to get allowed priority range: %s"
 					% e)
 		try:
-			schedutils.set_scheduler(pid, sched, prio)
+			self._scheduler_utils.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."
@@ -404,7 +482,7 @@ class SchedulerPlugin(base.Plugin):
 		self._scheduler_original[pid].cmdline = cmd
 
 	def _convert_sched_params(self, str_scheduler, str_priority):
-		scheduler = self._dict_schedcfg2num.get(str_scheduler)
+		scheduler = self._scheduler_utils.sched_cfg_to_num(str_scheduler)
 		if scheduler is None and str_scheduler != "*":
 			log.error("Invalid scheduler: %s. Scheduler and priority will be ignored."
 					% str_scheduler)
@@ -759,14 +837,14 @@ class SchedulerPlugin(base.Plugin):
 	# instead of OSError
 	# If PID doesn't exist, errno == ESRCH
 	def _get_affinity(self, pid):
-		res = schedutils.get_affinity(pid)
+		res = self._scheduler_utils.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)
+			self._scheduler_utils.set_affinity(pid, affinity)
 			return True
 		# Workaround for old python-schedutils (pre-0.4) which
 		# incorrectly raised SystemError instead of OSError