uncore: Allow to configure uncore ELC control

[spandruvada]

The Efficiency Latency Control (ELC) feature improves performance per watt. With this feature hardware power management algorithms optimize trade-off between latency and power consumption.

Add additional configuration for uncore plugin to include attributes to configure ELC.

Refer to Intel White Paper
https://www.intel.com/content/www/us/en/content-details/826934/intel-xeon-6-processors-performance-and-power-profiles-default-latency-optimized-mode-and-other-options.html?DocID=826934

Linux kernel documentation:
https://docs.kernel.org/admin-guide/pm/intel_uncore_frequency_scaling.html

Example configuration:

If the average CPU utilization is below 10% (elc_low_threshold_percent attribute below), uncore floor frequency of 1400MHz will be used (elc_floor_freq_khz attribute below) instead of hardware calculated minimum.

[uncore_all]
type=uncore
elc_floor_freq_khz=1400000
elc_high_threshold_enable=1
elc_high_threshold_percent=95
elc_low_threshold_percent=10

[jmencak]

Thank you for the PR, @spandruvada , much appreciated! Let me try to get my hands on a more recent Intel system that supports this so that I can test this.

[jmencak]

Got my hands on a hardware to test this on today. Hopefully I get to keep it for at least 2 weeks. However, I'm seeing:

2025-05-05 16:08:36,273 ERROR    tuned.units.manager: BUG: Unhandled exception in start_tuning: UncorePlugin._get_elc_floor_freq_khz() got multiple values for argument 'ignore_missing'
2025-05-05 16:08:36,273 ERROR    tuned.units.manager: Traceback (most recent call last):
  File "/usr/lib/python3.12/site-packages/tuned/units/manager.py", line 121, in _try_call
    return f(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/tuned/plugins/instance/instance.py", line 85, in apply_tuning
    self._plugin.instance_apply_tuning(self)
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 274, in instance_apply_tuning
    self._instance_apply_static(instance)
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 335, in _instance_apply_static
    self._execute_all_device_commands(instance, instance.assigned_devices)
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 461, in _execute_all_device_commands
    self._execute_device_command(instance, command, device, new_value)
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 524, in _execute_device_command
    new_value = self._check_and_save_value(instance, command, device, new_value)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 514, in _check_and_save_value
    current_value = self._get_current_value(instance, command, device)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/lib/python3.12/site-packages/tuned/plugins/base.py", line 509, in _get_current_value
    return command["get"](device, instance, ignore_missing=ignore_missing)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: UncorePlugin._get_elc_floor_freq_khz() got multiple values for argument 'ignore_missing'

2025-05-05 16:08:36,273 INFO     tuned.daemon.daemon: static tuning from profile 'uncore' applied

I'm testing this with the latest TuneD commit 9392599b, so things might have changed since you tested this, @spandruvada .

Edit: Getting this both on RHEL10 snapshot with python 3.12 and also CentOS Stream 9 with python 3.9.

[yarda]

It seems it was extension of the internal API earlier which broke it, it needs changes to the @command_get and @command_set, it now requires the instance parameter, e.g:

@command_get("elc_low_threshold_percent")
def _get_elc_low_threshold_percent(self, device, ignore_missing=False):
...
@command_set("elc_high_threshold_enable", per_device = True)
def _set_elc_high_threshold_enable(self, value, device, sim, remove):

needs to be now:

@command_get("elc_low_threshold_percent")
def _get_elc_low_threshold_percent(self, device, instance, ignore_missing=False):
...
@command_set("elc_high_threshold_enable", per_device = True)
def _set_elc_high_threshold_enable(self, value, device, instance, sim, remove):

This has to be changed in the all get/set.

[jmencak]

It seems it was extension of the internal API earlier which broke it, it needs changes to the @command_get and @command_set, it now requires the instance parameter, e.g:

@command_get("elc_low_threshold_percent")
def _get_elc_low_threshold_percent(self, device, ignore_missing=False):
...
@command_set("elc_high_threshold_enable", per_device = True)
def _set_elc_high_threshold_enable(self, value, device, sim, remove):

needs to be now:

@command_get("elc_low_threshold_percent")
def _get_elc_low_threshold_percent(self, device, instance, ignore_missing=False):
...
@command_set("elc_high_threshold_enable", per_device = True)
def _set_elc_high_threshold_enable(self, value, device, instance, sim, remove):

This has to be changed in the all get/set.

Thanks, @yarda . I've tested this PR successfully on RHEL10 snapshot with Granite Rapid AP (P-cores) and CentOS Stream 9 with Sierra Forest SP (SRF-SP) (E-cores) without any issues (all 4 new knobs were set).

This is the patch I used on top of @spandruvada 's work:

diff --git a/tuned/plugins/plugin_uncore.py b/tuned/plugins/plugin_uncore.py
index ec8e05e..0b5e8a8 100644
--- a/tuned/plugins/plugin_uncore.py
+++ b/tuned/plugins/plugin_uncore.py
@@ -243,7 +243,7 @@ class UncorePlugin(hotplug.Plugin):
 		return min_freq_khz
 
 	@command_get("elc_floor_freq_khz")
-	def _get_elc_floor_freq_khz(self, device, ignore_missing=False):
+	def _get_elc_floor_freq_khz(self, device, instance, ignore_missing=False):
 		if ignore_missing and not os.path.isdir(SYSFS_DIR):
 			return None
 
@@ -257,7 +257,7 @@ class UncorePlugin(hotplug.Plugin):
 		return elc_floor_freq_khz
 
 	@command_set("elc_floor_freq_khz", per_device = True)
-	def _set_elc_floor_freq_khz(self, value, device, sim, remove):
+	def _set_elc_floor_freq_khz(self, value, device, instance, sim, remove):
 		elc_floor_freq_khz = self._validate_value(device, IS_MAX, value)
 		if elc_floor_freq_khz is None:
 			return None
@@ -269,7 +269,7 @@ class UncorePlugin(hotplug.Plugin):
 		return self._set(device, "elc_floor_freq_khz", elc_floor_freq_khz)
 
 	@command_set("elc_high_threshold_percent", per_device = True)
-	def _set_elc_high_threshold_percent(self, value, device, sim, remove):
+	def _set_elc_high_threshold_percent(self, value, device, instance, sim, remove):
 		pct = self._validate_percent_value(value.rstrip("%"))
 		if pct is None:
 			return None
@@ -281,7 +281,7 @@ class UncorePlugin(hotplug.Plugin):
 		return self._set(device, "elc_high_threshold_percent", pct)
 
 	@command_get("elc_high_threshold_percent")
-	def _get_elc_high_threshold_percent(self, device, ignore_missing=False):
+	def _get_elc_high_threshold_percent(self, device, instance, ignore_missing=False):
 		if ignore_missing and not os.path.isdir(SYSFS_DIR):
 			return None
 
@@ -295,7 +295,7 @@ class UncorePlugin(hotplug.Plugin):
 		return elc_high_threshold_percent
 
 	@command_set("elc_low_threshold_percent", per_device = True)
-	def _set_elc_low_threshold_percent(self, value, device, sim, remove):
+	def _set_elc_low_threshold_percent(self, value, device, instance, sim, remove):
 		pct = self._validate_percent_value(value.rstrip("%"))
 		if pct is None:
 			return None
@@ -307,7 +307,7 @@ class UncorePlugin(hotplug.Plugin):
 		return self._set(device, "elc_low_threshold_percent", pct)
 
 	@command_get("elc_low_threshold_percent")
-	def _get_elc_low_threshold_percent(self, device, ignore_missing=False):
+	def _get_elc_low_threshold_percent(self, device, instance, ignore_missing=False):
 		if ignore_missing and not os.path.isdir(SYSFS_DIR):
 			return None
 
@@ -321,7 +321,7 @@ class UncorePlugin(hotplug.Plugin):
 		return elc_low_threshold_percent
 
 	@command_set("elc_high_threshold_enable", per_device = True)
-	def _set_elc_high_threshold_enable(self, value, device, sim, remove):
+	def _set_elc_high_threshold_enable(self, value, device, instance, sim, remove):
 		try:
 			enable = int(value)
 		except ValueError:
@@ -339,7 +339,7 @@ class UncorePlugin(hotplug.Plugin):
 		return self._set(device, "elc_high_threshold_enable", enable)
 
 	@command_get("elc_high_threshold_enable")
-	def _get_elc_high_threshold_enable(self, device, ignore_missing=False):
+	def _get_elc_high_threshold_enable(self, device, instance, ignore_missing=False):
 		if ignore_missing and not os.path.isdir(SYSFS_DIR):
 			return None
 

Srinivas, would you be able to update your PR so that we can merge this? Thank you and our apologies for the delay.