src/engine/mod.rs

@@ -7,6 +7,7 @@
 use serde::{Serialize, Deserialize};
 use std::collections::HashMap;
 use std::path::PathBuf;
+use tracing::warn;
 
 pub mod formatters;
 
@@ -180,6 +181,18 @@ impl OptimizerEngine {
             }
         }
 
+        let best_pl = if max_score > f32::MIN {
+            best_pl
+        } else {
+            profile.points.last().map(|p| p.power_w).unwrap_or(15.0)
+        };
+
+        // Safety Floor: Never recommend a TDP below 5W, as this bricks system performance.
+        if best_pl < 5.0 {
+            warn!("Heuristic suggested dangerously low PL1 ({:.1}W). Falling back to 15W safety floor.", best_pl);
+            return 15.0;
+        }
+
         best_pl
     }
 }

src/main.rs

@@ -161,6 +161,7 @@ fn main() -> Result<()> {
     // 5. Spawn Backend Orchestrator
     let sal_backend = sal.clone();
     let facts_backend = facts.clone();
+    let config_out = args.config_out.clone();
     let backend_handle = thread::spawn(move || {
         let workload = Box::new(StressNg::new());
         let mut orchestrator = BenchmarkOrchestrator::new(
@@ -169,6 +170,7 @@ fn main() -> Result<()> {
             workload,
             telemetry_tx,
             command_rx,
+            config_out,
         );
         orchestrator.run()
     });

src/orchestrator/mod.rs

@@ -12,6 +12,7 @@ use sysinfo::System;
 use std::sync::Arc;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Mutex;
+use std::path::PathBuf;
 
 use crate::sal::traits::{PlatformSal, SafetyStatus};
 use crate::sal::heuristic::discovery::SystemFactSheet;
@@ -40,6 +41,8 @@ pub struct BenchmarkOrchestrator {
     profile: ThermalProfile,
     /// Mathematics engine for data smoothing and optimization.
     engine: OptimizerEngine,
+    /// CLI override for the configuration output path.
+    optional_config_out: Option<PathBuf>,
     
     /// Sliding window of power readings (Watts).
     history_watts: VecDeque<f32>,
@@ -67,6 +70,7 @@ impl BenchmarkOrchestrator {
         workload: Box<dyn Workload>,
         telemetry_tx: mpsc::Sender<TelemetryState>,
         command_rx: mpsc::Receiver<UiCommand>,
+        optional_config_out: Option<PathBuf>,
     ) -> Self {
         let mut sys = System::new_all();
         sys.refresh_all();
@@ -92,6 +96,7 @@ impl BenchmarkOrchestrator {
             total_ram_gb,
             emergency_abort: Arc::new(AtomicBool::new(false)),
             emergency_reason: Arc::new(Mutex::new(None)),
+            optional_config_out,
         }
     }
 
@@ -222,12 +227,18 @@ impl BenchmarkOrchestrator {
             trip_temp: res.max_temp_c.max(95.0), 
         };
 
-        if let Some(throttled_path) = self.facts.paths.configs.get("throttled") {
+        // 1. Throttled (Merged if exists)
-            crate::engine::formatters::throttled::ThrottledTranslator::save(throttled_path, &config)?;
+        // PRIORITY: optional_config_out > facts discovery > fallback
-            self.log(&format!("✓ Saved '{}' (merged).", throttled_path.display()))?;
+        let throttled_path = self.optional_config_out.clone()
-            res.config_paths.insert("throttled".to_string(), throttled_path.clone());
+            .or_else(|| self.facts.paths.configs.get("throttled").cloned());
+
+        if let Some(path) = throttled_path {
+            crate::engine::formatters::throttled::ThrottledTranslator::save(&path, &config)?;
+            self.log(&format!("✓ Saved '{}'.", path.display()))?;
+            res.config_paths.insert("throttled".to_string(), path.clone());
         }
 
+        // 2. i8kmon
         if let Some(i8k_path) = self.facts.paths.configs.get("i8kmon") {
             let i8k_config = crate::engine::formatters::i8kmon::I8kmonConfig {
                 t_ambient: self.profile.ambient_temp,

src/sal/dell_xps_9380.rs

@@ -22,6 +22,11 @@ pub struct DellXps9380Sal {
     suppressed_services: Mutex<Vec<String>>,
     msr_file: Mutex<fs::File>,
     last_energy: Mutex<(u64, Instant)>,
+
+    // --- Original State for Restoration ---
+    original_pl1: Mutex<Option<u64>>,
+    original_pl2: Mutex<Option<u64>>,
+    original_fan_mode: Mutex<Option<String>>,
 }
 
 impl DellXps9380Sal {
@@ -53,6 +58,9 @@ impl DellXps9380Sal {
             last_energy: Mutex::new((initial_energy, Instant::now())),
             fact_sheet: facts,
             ctx,
+            original_pl1: Mutex::new(None),
+            original_pl2: Mutex::new(None),
+            original_fan_mode: Mutex::new(None),
         })
     }
 
@@ -126,12 +134,25 @@ impl PreflightAuditor for DellXps9380Sal {
 
 impl EnvironmentGuard for DellXps9380Sal {
     fn suppress(&self) -> Result<()> {
+        // 1. Snapshot Power Limits
+        if let Ok(pl1) = fs::read_to_string(&self.pl1_path) {
+            *self.original_pl1.lock().unwrap() = pl1.trim().parse().ok();
+        }
+        if let Ok(pl2) = fs::read_to_string(&self.pl2_path) {
+            *self.original_pl2.lock().unwrap() = pl2.trim().parse().ok();
+        }
+
+        // 2. Snapshot Fan Mode (Assumption: Dell BIOS Fan Control is active)
+        // We can't easily read current state of dell-bios-fan-control, so we assume 'auto' (1)
+        *self.original_fan_mode.lock().unwrap() = Some("1".to_string());
+
+        // 3. Stop Services
         let services = ["tlp", "thermald", "i8kmon"];
         let mut suppressed = self.suppressed_services.lock().unwrap();
         for s in services {
             if self.ctx.runner.run("systemctl", &["is-active", "--quiet", s]).is_ok() {
                 debug!("Suppressing service: {}", s);
-                self.ctx.runner.run("systemctl", &["stop", s])?;
+                let _ = self.ctx.runner.run("systemctl", &["stop", s]);
                 suppressed.push(s.to_string());
             }
         }
@@ -139,6 +160,20 @@ impl EnvironmentGuard for DellXps9380Sal {
     }
 
     fn restore(&self) -> Result<()> {
+        // 1. Restore Power Limits
+        if let Some(pl1) = *self.original_pl1.lock().unwrap() {
+            let _ = fs::write(&self.pl1_path, pl1.to_string());
+        }
+        if let Some(pl2) = *self.original_pl2.lock().unwrap() {
+            let _ = fs::write(&self.pl2_path, pl2.to_string());
+        }
+
+        // 2. Restore Fan Mode (BIOS Control)
+        if let Some(tool_path) = self.fact_sheet.paths.tools.get("dell_fan_ctrl") {
+            let _ = self.ctx.runner.run(&tool_path.to_string_lossy(), &["1"]);
+        }
+
+        // 3. Restart Services
         let mut suppressed = self.suppressed_services.lock().unwrap();
         for s in suppressed.drain(..) {
             let _ = self.ctx.runner.run("systemctl", &["start", &s]);
@@ -162,17 +197,23 @@ impl SensorBus for DellXps9380Sal {
     }
 
     fn get_power_w(&self) -> Result<f32> {
-        if self.pwr_path.to_string_lossy().contains("energy_uj") {
+        // FIX: Ensure we always read from energy_uj if available for delta calculation
+        let rapl_base = self.pl1_path.parent().context("RAPL path error")?;
+        let energy_path = rapl_base.join("energy_uj");
+
+        if energy_path.exists() {
             let mut last = self.last_energy.lock().unwrap();
-            let e2 = fs::read_to_string(&self.pwr_path)?.trim().parse::<u64>()?;
+            let e2_str = fs::read_to_string(&energy_path)?;
+            let e2 = e2_str.trim().parse::<u64>()?;
             let t2 = Instant::now();
             let (e1, t1) = *last;
             let delta_e = e2.wrapping_sub(e1);
             let delta_t = t2.duration_since(t1).as_secs_f32();
             *last = (e2, t2);
-            if delta_t < 0.01 { return Ok(0.0); }
+            if delta_t < 0.05 { return Ok(0.0); }
             Ok((delta_e as f32 / 1_000_000.0) / delta_t)
         } else {
+            // Fallback to power1_average if it exists (units are µW)
             let s = fs::read_to_string(&self.pwr_path)?;
             Ok(s.trim().parse::<f32>()? / 1000000.0)
         }

src/sal/generic_linux.rs

@@ -3,6 +3,7 @@ use std::path::{Path};
 use std::fs;
 use std::time::{Duration, Instant};
 use std::sync::Mutex;
+use tracing::{debug};
 
 use crate::sal::traits::{SensorBus, ActuatorBus, EnvironmentGuard, HardwareWatchdog, PreflightAuditor, AuditStep, AuditError, SafetyStatus, EnvironmentCtx};
 use crate::sal::heuristic::discovery::SystemFactSheet;
@@ -16,6 +17,10 @@ pub struct GenericLinuxSal {
     last_valid_temp: Mutex<(f32, Instant)>,
     current_pl1: Mutex<f32>,
     last_energy: Mutex<(u64, Instant)>,
+
+    // --- Original State for Restoration ---
+    original_pl1: Mutex<Option<u64>>,
+    original_pl2: Mutex<Option<u64>>,
 }
 
 impl GenericLinuxSal {
@@ -34,6 +39,8 @@ impl GenericLinuxSal {
             last_energy: Mutex::new((initial_energy, Instant::now())),
             fact_sheet: facts,
             ctx,
+            original_pl1: Mutex::new(None),
+            original_pl2: Mutex::new(None),
         }
     }
 
@@ -95,7 +102,7 @@ impl SensorBus for GenericLinuxSal {
         let delta_e = e2.wrapping_sub(e1);
         let delta_t = t2.duration_since(t1).as_secs_f32();
         *last = (e2, t2);
-        if delta_t < 0.01 { return Ok(0.0); }
+        if delta_t < 0.05 { return Ok(0.0); }
         Ok((delta_e as f32 / 1_000_000.0) / delta_t)
     }
 
@@ -160,12 +167,22 @@ impl ActuatorBus for GenericLinuxSal {
 
 impl EnvironmentGuard for GenericLinuxSal {
     fn suppress(&self) -> Result<()> {
+        // Snapshot Power Limits
+        if let Some(rapl_path) = self.fact_sheet.rapl_paths.first() {
+            if let Ok(pl1) = fs::read_to_string(rapl_path.join("constraint_0_power_limit_uw")) {
+                *self.original_pl1.lock().unwrap() = pl1.trim().parse().ok();
+            }
+            if let Ok(pl2) = fs::read_to_string(rapl_path.join("constraint_1_power_limit_uw")) {
+                *self.original_pl2.lock().unwrap() = pl2.trim().parse().ok();
+            }
+        }
+
         let mut suppressed = self.suppressed_services.lock().unwrap();
         for conflict_id in &self.fact_sheet.active_conflicts {
             if let Some(conflict) = self.db.conflicts.iter().find(|c| &c.id == conflict_id) {
                 for service in &conflict.services {
                     if self.ctx.runner.run("systemctl", &["is-active", "--quiet", service]).is_ok() {
-                        self.ctx.runner.run("systemctl", &["stop", service])?;
+                        let _ = self.ctx.runner.run("systemctl", &["stop", service]);
                         suppressed.push(service.clone());
                     }
                 }
@@ -175,6 +192,16 @@ impl EnvironmentGuard for GenericLinuxSal {
     }
 
     fn restore(&self) -> Result<()> {
+        // Restore Power Limits
+        if let Some(rapl_path) = self.fact_sheet.rapl_paths.first() {
+            if let Some(pl1) = *self.original_pl1.lock().unwrap() {
+                let _ = fs::write(rapl_path.join("constraint_0_power_limit_uw"), pl1.to_string());
+            }
+            if let Some(pl2) = *self.original_pl2.lock().unwrap() {
+                let _ = fs::write(rapl_path.join("constraint_1_power_limit_uw"), pl2.to_string());
+            }
+        }
+
         let mut suppressed = self.suppressed_services.lock().unwrap();
         for service in suppressed.drain(..) {
             let _ = self.ctx.runner.run("systemctl", &["start", &service]);

src/sal/heuristic/discovery.rs

@@ -1,11 +1,11 @@
 use std::fs;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::time::{Duration};
 use std::thread;
 use std::sync::mpsc;
 use std::collections::HashMap;
 use crate::sal::heuristic::schema::{SensorDiscovery, ActuatorDiscovery, Conflict, Discovery, Benchmarking};
+use crate::sys::SyscallRunner;
 use tracing::{debug, warn};
 
 /// Registry of dynamically discovered paths for configs and tools.
@@ -31,6 +31,7 @@ pub struct SystemFactSheet {
 /// Probes the system for hardware sensors, actuators, service conflicts, and paths.
 pub fn discover_facts(
     base_path: &Path,
+    runner: &dyn SyscallRunner,
     discovery: &Discovery,
     conflicts: &[Conflict],
     bench_config: Benchmarking,
@@ -45,7 +46,7 @@ pub fn discover_facts(
     let mut active_conflicts = Vec::new();
     for conflict in conflicts {
         for service in &conflict.services {
-            if is_service_active(service) {
+            if is_service_active(runner, service) {
                 debug!("Detected active conflict: {} (Service: {})", conflict.id, service);
                 active_conflicts.push(conflict.id.clone());
                 break;
@@ -93,7 +94,6 @@ fn discover_paths(base_path: &Path, discovery: &Discovery) -> PathRegistry {
                 break;
             }
         }
-        // If not found, use the first one as default if any exist
         if !registry.configs.contains_key(id) {
             if let Some(first) = candidates.first() {
                 registry.configs.insert(id.clone(), PathBuf::from(first));
@@ -142,7 +142,6 @@ fn discover_hwmon(base_path: &Path, cfg: &SensorDiscovery) -> (Option<PathBuf>,
             for hw_entry in hw_entries.flatten() {
                 let file_name = hw_entry.file_name().into_string().unwrap_or_default();
                 
-                // Temperature Sensors
                 if file_name.starts_with("temp") && file_name.ends_with("_label") {
                     if let Some(label) = read_sysfs_with_timeout(&hw_entry.path(), Duration::from_millis(100)) {
                         if cfg.temp_labels.iter().any(|l| label.contains(l)) {
@@ -154,7 +153,6 @@ fn discover_hwmon(base_path: &Path, cfg: &SensorDiscovery) -> (Option<PathBuf>,
                     }
                 }
 
-                // Fan Sensors
                 if file_name.starts_with("fan") && file_name.ends_with("_label") {
                     if let Some(label) = read_sysfs_with_timeout(&hw_entry.path(), Duration::from_millis(100)) {
                         if cfg.fan_labels.iter().any(|l| label.contains(l)) {
@@ -206,18 +204,9 @@ fn discover_rapl(base_path: &Path, cfg: &ActuatorDiscovery) -> Vec<PathBuf> {
     paths
 }
 
-/// Checks if a systemd service is currently active.
+/// Checks if a systemd service is currently active using the injected runner.
-pub fn is_service_active(service: &str) -> bool {
+pub fn is_service_active(runner: &dyn SyscallRunner, service: &str) -> bool {
-    let status = Command::new("systemctl")
+    runner.run("systemctl", &["is-active", "--quiet", service]).is_ok()
-        .arg("is-active")
-        .arg("--quiet")
-        .arg(service)
-        .status();
-
-    match status {
-        Ok(s) => s.success(),
-        Err(_) => false,
-    }
 }
 
 /// Helper to read a sysfs file with a timeout.

src/sal/heuristic/engine.rs

@@ -24,7 +24,7 @@ impl HeuristicEngine {
             .context("Failed to parse hardware_db.toml")?;
 
         // 2. Discover Facts
-        let facts = discover_facts(&ctx.sysfs_base, &db.discovery, &db.conflicts, db.benchmarking.clone());
+        let facts = discover_facts(&ctx.sysfs_base, ctx.runner.as_ref(), &db.discovery, &db.conflicts, db.benchmarking.clone());
         info!("System Identity: {} {}", facts.vendor, facts.model);
 
         // 3. Routing Logic

tests/heuristic_discovery_test.rs

@@ -1,5 +1,6 @@
 use ember_tune_rs::sal::heuristic::discovery::discover_facts;
 use ember_tune_rs::sal::heuristic::schema::{Discovery, SensorDiscovery, ActuatorDiscovery, Benchmarking};
+use ember_tune_rs::sys::MockSyscallRunner;
 use crate::common::fakesys::FakeSysBuilder;
 
 mod common;
@@ -35,7 +36,9 @@ fn test_heuristic_discovery_with_fakesys() {
         power_steps_watts: vec![10.0, 15.0],
     };
 
-    let facts = discover_facts(&fake.base_path(), &discovery, &[], benchmarking);
+    let runner = MockSyscallRunner::new();
+
+    let facts = discover_facts(&fake.base_path(), &runner, &discovery, &[], benchmarking);
 
     assert_eq!(facts.vendor, "Dell Inc.");
     assert_eq!(facts.model, "XPS 13 9380");

tests/orchestrator_e2e_test.rs

@@ -28,6 +28,7 @@ fn test_orchestrator_e2e_state_machine() {
         workload,
         telemetry_tx,
         command_rx,
+        None,
     );
 
     // For the purpose of this architecture audit, we've demonstrated the