[PATCH v2 3/9] Recipes.ENRT.ConfigMixins: add DisableTurboboostMixin

[Jan Tluka]

This mixin class provides recipe parameter 'disable_turboboost' that can be
used to disable CPU turboboost before running the tests.

It uses intel_pstate sysfs interface to disable the CPU feature and so
it is usable only by systems with Intel CPUs.

To use it pass 'disable_turboost=True' parameter when creating an instance of
BaseEnrtRecipe.

Signed-off-by: Jan Tluka <jtluka(a)redhat.com&gt;
---
 .../ConfigMixins/DisableTurboboostMixin.py    | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 lnst/Recipes/ENRT/ConfigMixins/DisableTurboboostMixin.py

diff --git a/lnst/Recipes/ENRT/ConfigMixins/DisableTurboboostMixin.py
b/lnst/Recipes/ENRT/ConfigMixins/DisableTurboboostMixin.py
new file mode 100644
index 00000000..dc3c0d62
--- /dev/null
+++ b/lnst/Recipes/ENRT/ConfigMixins/DisableTurboboostMixin.py
@@ -0,0 +1,54 @@
+from lnst.Common.Parameters import BoolParam
+from lnst.Controller.RecipeResults import ResultLevel
+from lnst.Recipes.ENRT.ConfigMixins import BaseSubConfigMixin
+
+class DisableTurboboostMixin(BaseSubConfigMixin):
+    disable_turboboost = BoolParam(default=False)
+
+    @property
+    def disable_turboboost_host_list(self):
+        """
+        The value of this property is a list of hosts for which the CPU turboboost
+        should be turned off. Derived class can override this property.
+        """
+        return []
+
+    def _is_turboboost_supported(self, host):
+        file_check = host.run(
+                "ls /sys/devices/system/cpu/intel_pstate/no_turbo",
+                job_level=ResultLevel.DEBUG)
+        return file_check.passed
+
+    def apply_sub_configuration(self, config):
+        super().apply_sub_configuration(config)
+
+        if self.params.disable_turboboost:
+            for host in self.disable_turboboost_host_list:
+                if self._is_turboboost_supported(host):
+                    # TODO: save previous state
+                    host.run("echo 1 >
/sys/devices/system/cpu/intel_pstate/no_turbo")
+
+    def generate_sub_configuration_description(self, config):
+        description = super().generate_sub_configuration_description(config)
+
+        if self.params.disable_turboboost:
+            for host in self.disable_turboboost_host_list:
+                if self._is_turboboost_supported(host):
+                    description.append("turboboost disabled through intel_pstate on
{}".format(host.hostid))
+                else:
+                    description.append("warning: user requested to disable
turboboost "\
+                            "through intel_pstate but the sysfs file is not
available "\
+                            "on host {}".format(host.hostid))
+        else:
+            description.append("configuration of turboboost through intel_pstate
skipped")
+
+        return description
+
+    def remove_sub_configuration(self, config):
+        if self.params.disable_turboboost:
+            for host in self.disable_turboboost_host_list:
+                if self._is_turboboost_supported(host):
+                    # TODO: restore previous state
+                    host.run("echo 0 >
/sys/devices/system/cpu/intel_pstate/no_turbo")
+
+        return super().remove_sub_configuration(config)
-- 
2.21.3