fix(server): make native VMM registration ownership explicit

pegaflow-server/src/http_server.rs

@@ -82,8 +82,17 @@ async fn cleanup_handler(
 ) -> impl IntoResponse {
     match query.id {
         None => {
-            let removed_tensors = state.registry.clear().await;
-            let removed_instances = state.engine.unregister_all_instances();
+            let engine = Arc::clone(&state.engine);
+            let registry = state.registry.clone();
+            let (removed_instances, removed_tensors) = tokio::spawn(async move {
+                let cleanup = registry.clear().await;
+                let removed_instances = engine.unregister_all_instances();
+                let removed_tensors = cleanup.tensor_count();
+                registry.finish_cleanup(cleanup).await;
+                (removed_instances, removed_tensors)
+            })
+            .await
+            .expect("cleanup-all task failed");
 
             if !removed_instances.is_empty() || removed_tensors > 0 {
                 warn!(
@@ -104,8 +113,19 @@ async fn cleanup_handler(
             )
         }
         Some(instance_id) => {
-            let removed_tensors = state.registry.drop_instance(instance_id.clone()).await;
-            match state.engine.unregister_instance(&instance_id) {
+            let engine = Arc::clone(&state.engine);
+            let registry = state.registry.clone();
+            let cleanup_id = instance_id.clone();
+            let (removed_tensors, unregister) = tokio::spawn(async move {
+                let cleanup = registry.drop_instance(cleanup_id.clone()).await;
+                let removed_tensors = cleanup.tensor_count();
+                let unregister = engine.unregister_instance(&cleanup_id);
+                registry.finish_cleanup(cleanup).await;
+                (removed_tensors, unregister)
+            })
+            .await
+            .expect("instance cleanup task failed");
+            match unregister {
                 Ok(()) => {
                     warn!(
                         "Cleanup instance {}: {} CUDA tensor(s) released",

pegaflow-server/src/lib.rs

@@ -94,7 +94,7 @@ pub struct Cli {
     pub enable_prometheus: bool,
 
     /// UDS path for native clients to send VMM allocation fds (SCM_RIGHTS). Empty disables.
-    #[arg(long, default_value = "/tmp/pegaflow-fd.sock")]
+    #[arg(long, default_value = "")]
     pub fd_socket_path: String,
 
     /// Init torch CUDA registry (vLLM path). False = torch-free, native VMM only.
@@ -306,7 +306,7 @@ fn init_cuda_driver() -> Result<(), std::io::Error> {
         .map_err(|err| std::io::Error::other(format!("failed to initialize CUDA driver: {err}")))
 }
 
-fn detect_cuda_devices() -> Result<Vec<i32>, std::io::Error> {
+fn detect_python_cuda_devices() -> Result<Vec<i32>, std::io::Error> {
     Python::attach(|py| -> pyo3::PyResult<Vec<i32>> {
         let torch = py.import("torch")?;
         let cuda = torch.getattr("cuda")?;
@@ -331,6 +331,15 @@ fn detect_cuda_devices() -> Result<Vec<i32>, std::io::Error> {
     })
 }
 
+fn detect_native_cuda_devices() -> Result<Vec<i32>, std::io::Error> {
+    let device_count = cudarc::driver::CudaContext::device_count().map_err(|err| {
+        std::io::Error::other(format!(
+            "failed to detect CUDA devices with the CUDA driver: {err}"
+        ))
+    })?;
+    Ok((0..device_count).collect())
+}
+
 fn init_python_cuda(device_ids: &[i32]) -> Result<(), std::io::Error> {
     if device_ids.is_empty() {
         return Err(std::io::Error::other("no CUDA devices to initialize"));
@@ -473,7 +482,11 @@ pub fn run() -> Result<(), Box<dyn Error>> {
     // Determine which devices to initialize
     let devices = if cli.devices.is_empty() {
         // Auto-detect all available devices
-        let detected = detect_cuda_devices()?;
+        let detected = if cli.python_registry {
+            detect_python_cuda_devices()?
+        } else {
+            detect_native_cuda_devices()?
+        };
         info!(
             "Auto-detected {} CUDA device(s): {:?}",
             detected.len(),
@@ -779,6 +792,13 @@ mod tests {
         );
     }
 
+    #[test]
+    fn cli_defaults_native_fd_side_channel_off() {
+        let cli = Cli::try_parse_from(["pegaflow-server"]).unwrap();
+
+        assert!(cli.fd_socket_path.is_empty());
+    }
+
     #[test]
     fn cli_nics_accepts_comma_separated_values() {
         let cli =