scheduler: Store saved affinity as a bitmask rather than list

Store saved CPU affinity of processes as a bitmask rather than
a CPU list. It should be much more memory-efficient.

Signed-off-by: Ondřej Lysoněk <olysonek@redhat.com>

tuned/plugins/plugin_scheduler.py

@@ -19,13 +19,28 @@ import errno
 log = tuned.logs.get()
 
 class SchedulerParams(object):
-	def __init__(self, cmdline = None, scheduler = None, priority = None,
-			affinity = None):
+	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 = {}
@@ -228,7 +243,7 @@ class SchedulerPlugin(base.Plugin):
 		try:
 			params = self._scheduler_original[pid]
 		except KeyError:
-			params = SchedulerParams()
+			params = SchedulerParams(self._cmd)
 			self._scheduler_original[pid] = params
 		if params.scheduler is None and params.priority is None:
 			params.scheduler = scheduler
@@ -260,7 +275,7 @@ class SchedulerPlugin(base.Plugin):
 		try:
 			params = self._scheduler_original[pid]
 		except KeyError:
-			params = SchedulerParams()
+			params = SchedulerParams(self._cmd)
 			self._scheduler_original[pid] = params
 		if params.affinity is None:
 			params.affinity = affinity

tuned/utils/commands.py

@@ -259,17 +259,21 @@ class commands:
 		if mask is None:
 			return None
 		mask = str(mask).replace(",", "")
-		cpu = 0
-		cpus = []
 		try:
 			m = int(mask, 16)
 		except ValueError:
 			log.error("invalid hexadecimal mask '%s'" % str(mask))
 			return []
-		while m > 0:
-			if m & 1:
+		return self.bitmask2cpulist(m)
+
+	# Converts an integer bitmask to a list of cpus (e.g. [0,3,4])
+	def bitmask2cpulist(self, mask):
+		cpu = 0
+		cpus = []
+		while mask > 0:
+			if mask & 1:
 				cpus.append(cpu)
-			m >>= 1
+			mask >>= 1
 			cpu += 1
 		return cpus
 
@@ -366,12 +370,10 @@ class commands:
 	def cpulist2hex(self, l):
 		if l is None:
 			return None
-		m = 0
 		ul = self.cpulist_unpack(l)
 		if ul is None:
 			return None
-		for v in ul:
-			m |= pow(2, v)
+		m = self.cpulist2bitmask(ul)
 		s = "%x" % m
 		ls = len(s)
 		if ls % 8 != 0:
@@ -379,6 +381,12 @@ class commands:
 		s = s.zfill(ls)
 		return ",".join(s[i:i + 8] for i in range(0, len(s), 8))
 
+	def cpulist2bitmask(self, l):
+		m = 0
+		for v in l:
+			m |= pow(2, v)
+		return m
+
 	def process_recommend_file(self, fname):
 		matching_profile = None
 		try: