feat: Use linear power model for SC20 experiments

2 files changed, 6 insertions, 3 deletions

diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
index 637432db..cd3e9a48 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/driver/SimpleBareMetalDriver.kt
@@ -209,7 +209,7 @@ public class SimpleBareMetalDriver(
                 }
             }
 
-            usageSignal.value = totalUsage
+            usageSignal.value = totalUsage / cpus.size
 
             try {
                 delay(duration)
diff --git a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/power/PowerModels.kt b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/power/PowerModels.kt
index 10390cd8..9ddbe08e 100644
--- a/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/power/PowerModels.kt
+++ b/opendc/opendc-compute/src/main/kotlin/com/atlarge/opendc/compute/metal/power/PowerModels.kt
@@ -36,7 +36,10 @@ public fun ConstantPowerModel(value: Double): PowerModel<BareMetalDriver> = { _
 
 /**
  * A power model that assumes a naive linear relation between power usage and host CPU utilization.
+ *
+ * @param idle The power draw in Watts on idle.
+ * @param max The maximum power draw in Watts of the server.
  */
-public fun LinearLoadPowerModel(base: Double, multiplier: Double): PowerModel<BareMetalDriver> = { driver ->
-    driver.usage.map { load -> base + multiplier * load }
+public fun LinearLoadPowerModel(idle: Double, max: Double): PowerModel<BareMetalDriver> = { driver ->
+    driver.usage.map { load -> (max - idle) * load + idle }
 }