simulator: Migrate frequency scaling governors to OS layer

This change moves the CPU frequency scaling governors from the
bare-metal/firmware layer (SimBareMetalMachine) to the OS/Hypervisor
layer (SimHypervisor) where it can make more informed decisions about
the CPU frequency based on the load of the operating system or
hypervisor.

2 files changed, 13 insertions, 11 deletions

diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
index 0bcfd9c6..b15692ec 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/SimHypervisorTest.kt
@@ -32,6 +32,7 @@ import org.junit.jupiter.api.BeforeEach
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.assertAll
 import org.junit.jupiter.api.assertDoesNotThrow
+import org.opendc.simulator.compute.cpufreq.PerformanceScalingGovernor
 import org.opendc.simulator.compute.model.MemoryUnit
 import org.opendc.simulator.compute.model.ProcessingNode
 import org.opendc.simulator.compute.model.ProcessingUnit
@@ -95,7 +96,7 @@ internal class SimHypervisorTest {
 
         val platform = SimResourceInterpreter(coroutineContext, clock)
         val machine = SimBareMetalMachine(platform, model, SimplePowerDriver(ConstantPowerModel(0.0)))
-        val hypervisor = SimFairShareHypervisor(platform, null, listener)
+        val hypervisor = SimFairShareHypervisor(platform, scalingGovernor = PerformanceScalingGovernor(), listener = listener)
 
         launch {
             machine.run(hypervisor)
@@ -169,7 +170,7 @@ internal class SimHypervisorTest {
         val machine = SimBareMetalMachine(
             platform, model, SimplePowerDriver(ConstantPowerModel(0.0))
         )
-        val hypervisor = SimFairShareHypervisor(platform, null, listener)
+        val hypervisor = SimFairShareHypervisor(platform, listener = listener)
 
         launch {
             machine.run(hypervisor)
diff --git a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/cpufreq/DemandScalingGovernorTest.kt b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/cpufreq/PerformanceScalingGovernorTest.kt
index c482d348..8e8b09c8 100644
--- a/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/cpufreq/DemandScalingGovernorTest.kt
+++ b/opendc-simulator/opendc-simulator-compute/src/test/kotlin/org/opendc/simulator/compute/cpufreq/PerformanceScalingGovernorTest.kt
@@ -26,23 +26,24 @@ import io.mockk.every
 import io.mockk.mockk
 import io.mockk.verify
 import org.junit.jupiter.api.Test
+import org.opendc.simulator.compute.SimProcessingUnit
 
 /**
- * Test suite for the [DemandScalingGovernor]
+ * Test suite for the [PerformanceScalingGovernor]
  */
-internal class DemandScalingGovernorTest {
+internal class PerformanceScalingGovernorTest {
     @Test
-    fun testSetDemandLimit() {
-        val ctx = mockk<ScalingContext>(relaxUnitFun = true)
+    fun testSetStartLimit() {
+        val cpu = mockk<SimProcessingUnit>(relaxUnitFun = true)
 
-        every { ctx.cpu.speed } returns 2100.0
+        every { cpu.model.frequency } returns 4100.0
+        every { cpu.speed } returns 2100.0
 
-        val logic = DemandScalingGovernor().createLogic(ctx)
+        val logic = PerformanceScalingGovernor().createLogic(cpu)
 
         logic.onStart()
-        verify(exactly = 0) { ctx.setTarget(any()) }
+        logic.onLimit(1.0)
 
-        logic.onLimit()
-        verify(exactly = 1) { ctx.setTarget(2100.0) }
+        verify(exactly = 1) { cpu.capacity = 4100.0 }
     }
 }