Refine subprocess reaping

llm/server.go

@@ -53,6 +53,7 @@ type llmServer struct {
 	estimatedTotal uint64 // Total size of model
 	totalLayers    uint64
 	gpuCount       int
+	loadDuration   time.Duration // Record how long it took the model to load
 
 	sem *semaphore.Weighted
 }
@@ -291,6 +292,7 @@ func NewLlamaServer(gpus gpu.GpuInfoList, model string, ggml *GGML, adapters, pr
 			sem:            semaphore.NewWeighted(int64(numParallel)),
 			totalLayers:    ggml.KV().BlockCount() + 1,
 			gpuCount:       gpuCount,
+			done:           make(chan error, 1),
 		}
 
 		s.cmd.Env = os.Environ()
@@ -339,6 +341,11 @@ func NewLlamaServer(gpus gpu.GpuInfoList, model string, ggml *GGML, adapters, pr
 			continue
 		}
 
+		// reap subprocess when it exits
+		go func() {
+			s.done <- s.cmd.Wait()
+		}()
+
 		return s, nil
 	}
 
@@ -486,6 +493,7 @@ func (s *llmServer) WaitUntilRunning(ctx context.Context) error {
 	expiresAt := time.Now().Add(10 * time.Minute) // be generous with timeout, large models can take a while to load
 
 	slog.Info("waiting for llama runner to start responding")
+	var lastStatus ServerStatus = -1
 
 	for {
 		select {
@@ -500,12 +508,6 @@ func (s *llmServer) WaitUntilRunning(ctx context.Context) error {
 			return fmt.Errorf("llama runner process has terminated: %v %s", err, msg)
 		default:
 		}
-		ctx, cancel := context.WithTimeout(context.Background(), 200*time.Millisecond)
-		defer cancel()
-		status, err := s.getServerStatus(ctx)
-		if err != nil {
-			slog.Debug("server not yet available", "error", err)
-		}
 		if time.Now().After(expiresAt) {
 			// timeout
 			msg := ""
@@ -521,14 +523,20 @@ func (s *llmServer) WaitUntilRunning(ctx context.Context) error {
 			}
 			return fmt.Errorf("llama runner process no longer running: %d %s", s.cmd.ProcessState.ExitCode(), msg)
 		}
+		ctx, cancel := context.WithTimeout(ctx, 200*time.Millisecond)
+		defer cancel()
+		status, _ := s.getServerStatus(ctx)
+		if lastStatus != status && status != ServerStatusReady {
+			// Only log on status changes
+			slog.Info("waiting for server to become available", "status", status.ToString())
+		}
 		switch status {
-		case ServerStatusLoadingModel:
-			time.Sleep(time.Millisecond * 250)
-			slog.Debug("loading model")
 		case ServerStatusReady:
-			slog.Info(fmt.Sprintf("llama runner started in %0.2f seconds", time.Since(start).Seconds()))
+			s.loadDuration = time.Since(start)
+			slog.Info(fmt.Sprintf("llama runner started in %0.2f seconds", s.loadDuration.Seconds()))
 			return nil
 		default:
+			lastStatus = status
 			time.Sleep(time.Millisecond * 250)
 			continue
 		}
@@ -930,8 +938,11 @@ func (s *llmServer) Close() error {
 		if err := s.cmd.Process.Kill(); err != nil {
 			return err
 		}
-
-		_ = s.cmd.Wait()
+		// if ProcessState is already populated, Wait already completed, no need to wait again
+		if s.cmd.ProcessState == nil {
+			slog.Debug("waiting for llama server to exit")
+			<-s.done
+		}
 
 		slog.Debug("llama server stopped")
 	}