feat: HWP scaling, C1E, closed-loop thermal governor for Intel CPUs

kernel/src/Sched/Scheduler.cpp

@@ -18,6 +18,7 @@
 #include <Hal/Apic/Interrupts.hpp>
 #include <Hal/GDT.hpp>
 #include <Hal/SmpBoot.hpp>
+#include <Hal/CpuPower.hpp>
 #include <Timekeeping/ApicTimer.hpp>
 #include <Api/WinServer.hpp>
 #include <Api/Heap.hpp>
@@ -811,6 +812,11 @@ namespace Sched {
         }
 
         ReclaimTerminated();
+
+        // Thermal governor step (rate-limited internally to 500 ms).
+        // Runs here because BSP maintenance is reached from both the idle
+        // loop and the timer tick, so it keeps running under full load.
+        Hal::CpuPower::ThermalTick(Timekeeping::GetMilliseconds());
     }
 
     uint64_t GetNextDeadlineTick() {
@@ -922,6 +928,11 @@ namespace Sched {
     void Tick(uint32_t elapsedMs) {
         auto* cpu = Smp::GetCurrentCpuData();
 
+        // Pick up thermal-governor frequency changes (HWP requests are
+        // per-core MSRs, so every CPU applies them itself). No-op unless
+        // the governor bumped the policy epoch since our last tick.
+        Hal::CpuPower::ApplyPolicyIfChanged();
+
         // BSP: wake sleeping processes and reclaim terminated slots
         if (cpu->cpuIndex == 0) {
             RunBspMaintenance();