[PATCH v3 2/8] Recipes.ENRT.ConfigMixins: add DisableIdleStatesMixin

[Jan Tluka]

This mixin class extends BaseEnrtRecipe with ability to control the CPU idle
states before running the tests.

The class adds 'minimal_idlestates_latency' parameter that is passed as the
latency argument (-D) of the 'cpupower idle-set' that will disable all idle
states with an equal or higher latency than the specified value.

If the value is 0 this will effectively disable all CPU idle states.

Signed-off-by: Jan Tluka <jtluka(a)redhat.com&gt;
---
 .../ConfigMixins/DisableIdleStatesMixin.py    | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 lnst/Recipes/ENRT/ConfigMixins/DisableIdleStatesMixin.py

diff --git a/lnst/Recipes/ENRT/ConfigMixins/DisableIdleStatesMixin.py
b/lnst/Recipes/ENRT/ConfigMixins/DisableIdleStatesMixin.py
new file mode 100644
index 00000000..ca45dfb3
--- /dev/null
+++ b/lnst/Recipes/ENRT/ConfigMixins/DisableIdleStatesMixin.py
@@ -0,0 +1,42 @@
+from lnst.Common.Parameters import IntParam
+from lnst.Recipes.ENRT.ConfigMixins import BaseSubConfigMixin
+
+class DisableIdleStatesMixin(BaseSubConfigMixin):
+    minimal_idlestates_latency = IntParam()
+
+    @property
+    def disable_idlestates_host_list(self):
+        """
+        The value of this property is a list of hosts for which the CPU idle
+        states should be turned off. Derived class can override this property.
+        """
+        return []
+
+    def apply_sub_configuration(self, config):
+        super().apply_sub_configuration(config)
+
+        latency = getattr(self.params, "minimal_idlestates_latency", None)
+        if latency is not None:
+            for host in self.disable_idlestates_host_list:
+                # TODO: save previous state
+                host.run("cpupower idle-set -D {}".format(latency))
+
+    def generate_sub_configuration_description(self, config):
+        description = super().generate_sub_configuration_description(config)
+
+        latency = getattr(self.params, "minimal_idlestates_latency", None)
+        if latency is not None:
+            for host in self.disable_idlestates_host_list:
+                description.append("disabled idle states with latency higher than
"\
+                        "{} on host {}".format(latency, host.hostid)
+                        )
+        else:
+            description.append("configuration of idle states skipped")
+
+        return description
+
+    def remove_sub_configuration(self, config):
+        for host in self.disable_idlestates_host_list:
+            host.run("cpupower idle-set -E")
+
+        return super().remove_sub_configuration(config)
-- 
2.21.3