Add an ACPI plugin

Resolves: RHEL-16966

At this point, the plugin supports setting a single sysfs attribute,
platform_profile.

The 3 basic ACPI platform profiles are low-power, balanced, and
performance. These are mapped to the generic powersave,
balanced, and *-performance TuneD profiles.

doc/manual/modules/performance/ref_available-tuned-plug-ins.adoc

@@ -215,3 +215,27 @@ cmdline=isolcpus=2
 
 ====
 --
+
+`acpi`::
+
+Configures the ACPI driver.
++
+The only currently supported option is
+[option]`platform_profile`, which sets the ACPI
+platform profile sysfs attribute,
+a generic power/performance preference API for other drivers.
+Multiple profiles can be specified, separated by `|`.
+The first available profile is selected.
++
+--
+.Selecting a platform profile
+====
+----
+[acpi]
+platform_profile=low-power|quiet
+----
+Using this option, *TuneD* will try to set the platform profile
+to `low-power`. If that fails (e.g, because the system does not
+support the profile), it will try to set it to `quiet`.
+====
+--

profiles/accelerator-performance/tuned.conf

@@ -11,6 +11,9 @@ energy_perf_bias=performance
 min_perf_pct=100
 force_latency=99
 
+[acpi]
+platform_profile=performance
+
 [disk]
 readahead=>4096
 

profiles/balanced/tuned.conf

@@ -14,6 +14,9 @@ governor=conservative|powersave
 energy_perf_bias=normal
 energy_performance_preference=balance_performance
 
+[acpi]
+platform_profile=balanced
+
 [audio]
 timeout=10
 

profiles/latency-performance/tuned.conf

@@ -11,6 +11,9 @@ governor=performance
 energy_perf_bias=performance
 min_perf_pct=100
 
+[acpi]
+platform_profile=performance
+
 [sysctl]
 # If a workload mostly uses anonymous memory and it hits this limit, the entire
 # working set is buffered for I/O, and any more write buffering would require

profiles/powersave/tuned.conf

@@ -10,6 +10,9 @@ governor=ondemand|powersave
 energy_perf_bias=powersave|power
 energy_performance_preference=power
 
+[acpi]
+platform_profile=low-power|quiet
+
 [eeepc_she]
 
 [vm]

profiles/throughput-performance/tuned.conf

@@ -15,6 +15,9 @@ energy_perf_bias=performance
 min_perf_pct=100
 energy_performance_preference=performance
 
+[acpi]
+platform_profile=performance
+
 # Marvell ThunderX
 [vm.thunderx]
 type=vm

tuned/consts.py

@@ -66,6 +66,9 @@ SYSTEMD_CPUAFFINITY_VAR = "CPUAffinity"
 # irqbalance plugin configuration
 IRQBALANCE_SYSCONFIG_FILE = "/etc/sysconfig/irqbalance"
 
+# acpi plugin configuration
+ACPI_DIR = "/sys/firmware/acpi"
+
 # built-in functions configuration
 SYSFS_CPUS_PATH = "/sys/devices/system/cpu"
 

tuned/plugins/plugin_acpi.py

@@ -0,0 +1,81 @@
+from . import base
+from .decorators import *
+import os
+import errno
+import tuned.logs
+from tuned.consts import ACPI_DIR
+
+log = tuned.logs.get()
+
+
+class ACPIPlugin(base.Plugin):
+	"""
+	`acpi`::
+
+	Configures the ACPI driver.
+	+
+	The only currently supported option is
+	[option]`platform_profile`, which sets the ACPI
+	platform profile sysfs attribute,
+	a generic power/performance preference API for other drivers.
+	Multiple profiles can be specified, separated by `|`.
+	The first available profile is selected.
+	+
+	--
+	.Selecting a platform profile
+	====
+	----
+	[acpi]
+	platform_profile=balanced|low-power
+	----
+	Using this option, *TuneD* will try to set the platform profile
+	to `balanced`. If that fails, it will try to set it to `low-power`.
+	====
+	--
+	"""
+	def __init__(self, *args, **kwargs):
+		super(ACPIPlugin, self).__init__(*args, **kwargs)
+
+	@classmethod
+	def _get_config_options(cls):
+		return {"platform_profile": None}
+
+	def _instance_init(self, instance):
+		instance._has_static_tuning = True
+		instance._has_dynamic_tuning = False
+
+	def _instance_cleanup(self, instance):
+		pass
+
+	@classmethod
+	def _platform_profile_choices_path(cls):
+		return os.path.join(ACPI_DIR, "platform_profile_choices")
+
+	@classmethod
+	def _platform_profile_path(cls):
+		return os.path.join(ACPI_DIR, "platform_profile")
+
+	@command_set("platform_profile")
+	def _set_platform_profile(self, profiles, sim, remove):
+		if not os.path.isfile(self._platform_profile_path()):
+			log.debug("ACPI platform_profile is not supported on this system")
+			return None
+		profiles = [profile.strip() for profile in profiles.split('|')]
+		avail_profiles = set(self._cmd.read_file(self._platform_profile_choices_path()).split())
+		for profile in profiles:
+			if profile in avail_profiles:
+				if not sim:
+					log.info("Setting platform_profile to '%s'" % profile)
+					self._cmd.write_to_file(self._platform_profile_path(), profile, \
+						no_error=[errno.ENOENT] if remove else False)
+				return profile
+			log.warn("Requested platform_profile '%s' unavailable" % profile)
+		log.error("Failed to set platform_profile. Is the value in the profile correct?")
+		return None
+
+	@command_get("platform_profile")
+	def _get_platform_profile(self, ignore_missing=False):
+		if not os.path.isfile(self._platform_profile_path()):
+			log.debug("ACPI platform_profile is not supported on this system")
+			return None
+		return self._cmd.read_file(self._platform_profile_path()).strip()