perf: build graph for next batch async to keep GPU busy (#11863)

* perf: build graph for next batch in parallel to keep GPU busy

This refactors the main run loop of the ollama runner to perform the main GPU
intensive tasks (Compute+Floats) in a go routine so we can prepare the next
batch in parallel to reduce the amount of time the GPU stalls waiting for the
next batch of work.

* tests: tune integration tests for ollama engine

This tunes the integration tests to focus more on models supported
by the new engine.

integration/README.md

@@ -2,10 +2,13 @@
 
 This directory contains integration tests to exercise Ollama end-to-end to verify behavior
 
-By default, these tests are disabled so `go test ./...` will exercise only unit tests.  To run integration tests you must pass the integration tag.  `go test -tags=integration ./...`
+By default, these tests are disabled so `go test ./...` will exercise only unit tests.  To run integration tests you must pass the integration tag.  `go test -tags=integration ./...` Some tests require additional tags to enable to allow scoped testing to keep the duration reasonable.  For example, testing a broad set of models requires `-tags=integration,models` and a longer timeout (~60m or more depending on the speed of your GPU.). To view the current set of tag combinations use `find integration -type f | xargs grep "go:build"`
 
 
 The integration tests have 2 modes of operating.
 
 1. By default, they will start the server on a random port, run the tests, and then shutdown the server.
-2. If `OLLAMA_TEST_EXISTING` is set to a non-empty string, the tests will run against an existing running server, which can be remote
+2. If `OLLAMA_TEST_EXISTING` is set to a non-empty string, the tests will run against an existing running server, which can be remote based on your `OLLAMA_HOST` environment variable
+
+> [!IMPORTANT]
+> Before running the tests locally without the "test existing" setting, compile ollama from the top of the source tree  `go build .` in addition to GPU support with cmake if applicable on your platform.  The integration tests expect to find an ollama binary at the top of the tree.

integration/api_test.go

@@ -390,7 +390,7 @@ func TestAPIEmbeddings(t *testing.T) {
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
 	req := api.EmbeddingRequest{
-		Model:  "orca-mini",
+		Model:  libraryEmbedModels[0],
 		Prompt: "why is the sky blue?",
 		Options: map[string]interface{}{
 			"temperature": 0,

integration/basic_test.go

@@ -11,7 +11,6 @@ import (
 	"time"
 
 	"github.com/ollama/ollama/api"
-	"github.com/stretchr/testify/require"
 )
 
 func TestBlueSky(t *testing.T) {
@@ -37,8 +36,8 @@ func TestUnicode(t *testing.T) {
 	// Set up the test data
 	req := api.GenerateRequest{
 		// DeepSeek has a Unicode tokenizer regex, making it a unicode torture test
-		Model:  "deepseek-coder-v2:16b-lite-instruct-q2_K",
+		Model:  "deepseek-coder-v2:16b-lite-instruct-q2_K", // TODO is there an ollama-engine model we can switch to and keep the coverage?
-		Prompt: "天空为什么是蓝色的?",
+		Prompt: "天空为什么是蓝色的?",                               // Why is the sky blue?
 		Stream: &stream,
 		Options: map[string]any{
 			"temperature": 0,
@@ -50,8 +49,20 @@ func TestUnicode(t *testing.T) {
 	}
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
-	require.NoError(t, PullIfMissing(ctx, client, req.Model))
+	if err := PullIfMissing(ctx, client, req.Model); err != nil {
-	DoGenerate(ctx, t, client, req, []string{"散射", "频率"}, 120*time.Second, 120*time.Second)
+		t.Fatal(err)
+	}
+	slog.Info("loading", "model", req.Model)
+	err := client.Generate(ctx, &api.GenerateRequest{Model: req.Model}, func(response api.GenerateResponse) error { return nil })
+	if err != nil {
+		t.Fatalf("failed to load model %s: %s", req.Model, err)
+	}
+	skipIfNotGPULoaded(ctx, t, client, req.Model, 100)
+
+	DoGenerate(ctx, t, client, req, []string{
+		"散射", // scattering
+		"频率", // frequency
+	}, 120*time.Second, 120*time.Second)
 }
 
 func TestExtendedUnicodeOutput(t *testing.T) {
@@ -69,7 +80,9 @@ func TestExtendedUnicodeOutput(t *testing.T) {
 	}
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
-	require.NoError(t, PullIfMissing(ctx, client, req.Model))
+	if err := PullIfMissing(ctx, client, req.Model); err != nil {
+		t.Fatal(err)
+	}
 	DoGenerate(ctx, t, client, req, []string{"😀", "😊", "😁", "😂", "😄", "😃"}, 120*time.Second, 120*time.Second)
 }
 
@@ -84,7 +97,9 @@ func TestUnicodeModelDir(t *testing.T) {
 	}
 
 	modelDir, err := os.MkdirTemp("", "ollama_埃")
-	require.NoError(t, err)
+	if err != nil {
+		t.Fatal(err)
+	}
 	defer os.RemoveAll(modelDir)
 	slog.Info("unicode", "OLLAMA_MODELS", modelDir)
 

integration/concurrency_test.go

@@ -14,8 +14,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/envconfig"
 	"github.com/ollama/ollama/format"
@@ -79,21 +77,21 @@ func TestMultiModelStress(t *testing.T) {
 		t.Fatal(err)
 	}
 
+	// All models compatible with ollama-engine
 	smallModels := []string{
 		"llama3.2:1b",
 		"qwen3:0.6b",
-		"gemma:2b",
+		"gemma2:2b",
-		"deepseek-r1:1.5b",
+		"deepseek-r1:1.5b", // qwen2 arch
-		"starcoder2:3b",
+		"gemma3:270m",
 	}
 	mediumModels := []string{
-		"qwen3:8b",
+		"llama3.2:3b",    // ~3.4G
-		"llama2",
+		"qwen3:8b",       // ~6.6G
-		"deepseek-r1:7b",
+		"gpt-oss:20b",    // ~15G
-		"mistral",
+		"deepseek-r1:7b", // ~5.6G
-		"dolphin-mistral",
+		"gemma3:4b",      // ~5.8G
-		"gemma:7b",
+		"gemma2:9b",      // ~8.1G
-		"codellama:7b",
 	}
 
 	var chosenModels []string
@@ -114,7 +112,9 @@ func TestMultiModelStress(t *testing.T) {
 
 	// Make sure all the models are pulled before we get started
 	for _, model := range chosenModels {
-		require.NoError(t, PullIfMissing(ctx, client, model))
+		if err := PullIfMissing(ctx, client, model); err != nil {
+			t.Fatal(err)
+		}
 	}
 
 	// Determine how many models we can load in parallel before we exceed VRAM

integration/context_test.go

@@ -22,7 +22,7 @@ func TestLongInputContext(t *testing.T) {
 	defer cancel()
 	// Set up the test data
 	req := api.GenerateRequest{
-		Model:  "llama2",
+		Model:  smol,
 		Prompt: "Oh, don’t speak to me of Austria. Perhaps I don’t understand things, but Austria never has wished, and does not wish, for war. She is betraying us! Russia alone must save Europe. Our gracious sovereign recognizes his high vocation and will be true to it. That is the one thing I have faith in! Our good and wonderful sovereign has to perform the noblest role on earth, and he is so virtuous and noble that God will not forsake him. He will fulfill his vocation and crush the hydra of revolution, which has become more terrible than ever in the person of this murderer and villain! We alone must avenge the blood of the just one.... Whom, I ask you, can we rely on?... England with her commercial spirit will not and cannot understand the Emperor Alexander’s loftiness of soul. She has refused to evacuate Malta. She wanted to find, and still seeks, some secret motive in our actions. What answer did Novosíltsev get? None. The English have not understood and cannot understand the self-abnegation of our Emperor who wants nothing for himself, but only desires the good of mankind. And what have they promised? Nothing! And what little they have promised they will not perform! Prussia has always declared that Buonaparte is invincible, and that all Europe is powerless before him.... And I don’t believe a word that Hardenburg says, or Haugwitz either. This famous Prussian neutrality is just a trap. I have faith only in God and the lofty destiny of our adored monarch. He will save Europe! What country is this referring to?",
 		Stream: &stream,
 		Options: map[string]any{
@@ -36,7 +36,7 @@ func TestLongInputContext(t *testing.T) {
 	if err := PullIfMissing(ctx, client, req.Model); err != nil {
 		t.Fatalf("PullIfMissing failed: %v", err)
 	}
-	DoGenerate(ctx, t, client, req, []string{"russia", "germany", "france", "england", "austria", "prussia"}, 120*time.Second, 10*time.Second)
+	DoGenerate(ctx, t, client, req, []string{"russia", "germany", "france", "england", "austria", "prussia", "individuals", "coalition", "conflict"}, 120*time.Second, 10*time.Second)
 }
 
 func TestContextExhaustion(t *testing.T) {
@@ -49,7 +49,7 @@ func TestContextExhaustion(t *testing.T) {
 	defer cancel()
 	// Set up the test data
 	req := api.GenerateRequest{
-		Model:  "llama2",
+		Model:  smol,
 		Prompt: "Write me a story with a ton of emojis?",
 		Stream: &stream,
 		Options: map[string]any{
@@ -63,10 +63,10 @@ func TestContextExhaustion(t *testing.T) {
 	if err := PullIfMissing(ctx, client, req.Model); err != nil {
 		t.Fatalf("PullIfMissing failed: %v", err)
 	}
-	DoGenerate(ctx, t, client, req, []string{"once", "upon", "lived"}, 120*time.Second, 10*time.Second)
+	DoGenerate(ctx, t, client, req, []string{"once", "upon", "lived", "sunny", "cloudy", "clear", "water"}, 120*time.Second, 10*time.Second)
 }
 
-// Send multiple requests with prior context and ensure the response is coherant and expected
+// Send multiple generate requests with prior context and ensure the response is coherant and expected
 func TestGenerateWithHistory(t *testing.T) {
 	modelOverride := ollamaEngineChatModels[0] // Most recent ollama engine model
 	req, resp := GenerateRequests()
@@ -111,5 +111,56 @@ func TestGenerateWithHistory(t *testing.T) {
 		}(i)
 	}
 	wg.Wait()
-
+}
+
+// Send multiple chat requests with prior context and ensure the response is coherant and expected
+func TestChatWithHistory(t *testing.T) {
+	modelOverride := ollamaEngineChatModels[0] // Most recent ollama engine model
+	req, resp := ChatRequests()
+	numParallel := 2
+	iterLimit := 2
+
+	softTimeout, hardTimeout := getTimeouts(t)
+	ctx, cancel := context.WithTimeout(context.Background(), hardTimeout)
+	defer cancel()
+	client, _, cleanup := InitServerConnection(ctx, t)
+	defer cleanup()
+
+	// Get the server running (if applicable) warm the model up with a single initial empty request
+	slog.Info("loading", "model", modelOverride)
+	err := client.Generate(ctx,
+		&api.GenerateRequest{Model: modelOverride, KeepAlive: &api.Duration{Duration: 10 * time.Second}},
+		func(response api.GenerateResponse) error { return nil },
+	)
+	if err != nil {
+		t.Fatalf("failed to load model %s: %s", modelOverride, err)
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(numParallel)
+	for i := range numParallel {
+		go func(i int) {
+			defer wg.Done()
+			k := i % len(req)
+			req[k].Model = modelOverride
+			for j := 0; j < iterLimit; j++ {
+				if time.Now().Sub(started) > softTimeout {
+					slog.Info("exceeded soft timeout, winding down test")
+					return
+				}
+				slog.Info("Starting", "thread", i, "iter", j)
+				// On slower GPUs it can take a while to process the concurrent requests
+				// so we allow a much longer initial timeout
+				assistant := DoChat(ctx, t, client, req[k], resp[k], 120*time.Second, 20*time.Second)
+				if assistant == nil {
+					t.Fatalf("didn't get an assistant response for context")
+				}
+				req[k].Messages = append(req[k].Messages,
+					*assistant,
+					api.Message{Role: "user", Content: "tell me more!"},
+				)
+			}
+		}(i)
+	}
+	wg.Wait()
 }

integration/llm_image_test.go

@@ -9,7 +9,6 @@ import (
 	"time"
 
 	"github.com/ollama/ollama/api"
-	"github.com/stretchr/testify/require"
 )
 
 func TestVisionModels(t *testing.T) {
@@ -32,7 +31,9 @@ func TestVisionModels(t *testing.T) {
 	for _, v := range testCases {
 		t.Run(v.model, func(t *testing.T) {
 			image, err := base64.StdEncoding.DecodeString(imageEncoding)
-			require.NoError(t, err)
+			if err != nil {
+				t.Fatal(err)
+			}
 			req := api.GenerateRequest{
 				Model:  v.model,
 				Prompt: "what does the text in this image say?",
@@ -52,7 +53,9 @@ func TestVisionModels(t *testing.T) {
 			// Note: sometimes it returns "the ollamas" sometimes "the ollams"
 			resp := "the ollam"
 			defer cleanup()
-			require.NoError(t, PullIfMissing(ctx, client, req.Model))
+			if err := PullIfMissing(ctx, client, req.Model); err != nil {
+				t.Fatal(err)
+			}
 			// llava models on CPU can be quite slow to start
 			DoGenerate(ctx, t, client, req, []string{resp}, 240*time.Second, 30*time.Second)
 		})
@@ -62,7 +65,9 @@ func TestVisionModels(t *testing.T) {
 func TestIntegrationSplitBatch(t *testing.T) {
 	skipUnderMinVRAM(t, 6)
 	image, err := base64.StdEncoding.DecodeString(imageEncoding)
-	require.NoError(t, err)
+	if err != nil {
+		t.Fatal(err)
+	}
 	req := api.GenerateRequest{
 		Model: "gemma3:4b",
 		// Fill up a chunk of the batch so the image will partially spill over into the next one
@@ -84,7 +89,9 @@ func TestIntegrationSplitBatch(t *testing.T) {
 	defer cancel()
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
-	require.NoError(t, PullIfMissing(ctx, client, req.Model))
+	if err := PullIfMissing(ctx, client, req.Model); err != nil {
+		t.Fatal(err)
+	}
 	// llava models on CPU can be quite slow to start,
 	DoGenerate(ctx, t, client, req, []string{resp}, 120*time.Second, 30*time.Second)
 }

integration/llm_test.go

@@ -1,47 +0,0 @@
-//go:build integration
-
-package integration
-
-import (
-	"context"
-	"testing"
-	"time"
-
-	"github.com/ollama/ollama/api"
-)
-
-// TODO - this would ideally be in the llm package, but that would require some refactoring of interfaces in the server
-//        package to avoid circular dependencies
-
-var (
-	stream = false
-	req    = [2]api.GenerateRequest{
-		{
-			Model:  smol,
-			Prompt: "why is the ocean blue?",
-			Stream: &stream,
-			Options: map[string]any{
-				"seed":        42,
-				"temperature": 0.0,
-			},
-		}, {
-			Model:  smol,
-			Prompt: "what is the origin of the us thanksgiving holiday?",
-			Stream: &stream,
-			Options: map[string]any{
-				"seed":        42,
-				"temperature": 0.0,
-			},
-		},
-	}
-	resp = [2][]string{
-		{"sunlight", "scattering", "interact"},
-		{"england", "english", "massachusetts", "pilgrims"},
-	}
-)
-
-func TestIntegrationSimple(t *testing.T) {
-	ctx, cancel := context.WithTimeout(context.Background(), time.Second*120)
-	defer cancel()
-	GenerateTestHelper(ctx, t, req[0], resp[0])
-}

integration/max_queue_test.go

@@ -13,12 +13,12 @@ import (
 	"testing"
 	"time"
 
-	"github.com/stretchr/testify/require"
-
 	"github.com/ollama/ollama/api"
 )
 
 func TestMaxQueue(t *testing.T) {
+	t.Skip("this test needs to be re-evaluated to use a proper embedding model")
+
 	if os.Getenv("OLLAMA_TEST_EXISTING") != "" {
 		t.Skip("Max Queue test requires spawning a local server so we can adjust the queue size")
 		return
@@ -45,7 +45,9 @@ func TestMaxQueue(t *testing.T) {
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
 
-	require.NoError(t, PullIfMissing(ctx, client, req.Model))
+	if err := PullIfMissing(ctx, client, req.Model); err != nil {
+		t.Fatal(err)
+	}
 
 	// Context for the worker threads so we can shut them down
 	// embedCtx, embedCancel := context.WithCancel(ctx)
@@ -89,7 +91,9 @@ func TestMaxQueue(t *testing.T) {
 			switch {
 			case genErr == nil:
 				successCount++
-				require.Greater(t, len(resp.Embedding), 5) // somewhat arbitrary, but sufficient to be reasonable
+				if len(resp.Embedding) < 5 { // somewhat arbitrary, but sufficient to be reasonable
+					t.Fatalf("embeddings shorter than expected: %d", len(resp.Embedding))
+				}
 			case errors.Is(genErr, context.Canceled):
 				canceledCount++
 			case strings.Contains(genErr.Error(), "busy"):
@@ -97,7 +101,9 @@ func TestMaxQueue(t *testing.T) {
 			case strings.Contains(genErr.Error(), "connection reset by peer"):
 				resetByPeerCount++
 			default:
-				require.NoError(t, genErr, "%d request failed", i)
+				if genErr != nil {
+					t.Fatalf("%d request failed", i)
+				}
 			}
 
 			slog.Info("embed finished", "id", i)
@@ -108,8 +114,13 @@ func TestMaxQueue(t *testing.T) {
 	embedwg.Wait()
 
 	slog.Info("embeds completed", "success", successCount, "busy", busyCount, "reset", resetByPeerCount, "canceled", canceledCount)
-	require.Equal(t, resetByPeerCount, 0, "Connections reset by peer, have you updated your fd and socket limits?")
+	if resetByPeerCount != 0 {
-	require.True(t, busyCount > 0, "no requests hit busy error but some should have")
+		t.Fatalf("Connections reset by peer, have you updated your fd and socket limits? %d", resetByPeerCount)
-	require.True(t, canceledCount == 0, "no requests should have been canceled due to timeout")
+	}
-
+	if busyCount == 0 {
+		t.Fatalf("no requests hit busy error but some should have")
+	}
+	if canceledCount > 0 {
+		t.Fatalf("no requests should have been canceled due to timeout %d", canceledCount)
+	}
 }

integration/utils_test.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"math"
 	"math/rand"
 	"net"
 	"net/http"
@@ -25,11 +26,11 @@ import (
 	"github.com/ollama/ollama/api"
 	"github.com/ollama/ollama/app/lifecycle"
 	"github.com/ollama/ollama/format"
-	"github.com/stretchr/testify/require"
 )
 
 var (
-	smol = "llama3.2:1b"
+	smol   = "llama3.2:1b"
+	stream = false
 )
 
 var (
@@ -435,7 +436,9 @@ func InitServerConnection(ctx context.Context, t *testing.T) (*api.Client, strin
 		}
 		lifecycle.ServerLogFile = fp.Name()
 		fp.Close()
-		require.NoError(t, startServer(t, ctx, testEndpoint))
+		if err := startServer(t, ctx, testEndpoint); err != nil {
+			t.Fatal(err)
+		}
 	}
 
 	return client, testEndpoint, func() {
@@ -468,7 +471,9 @@ func InitServerConnection(ctx context.Context, t *testing.T) (*api.Client, strin
 func GenerateTestHelper(ctx context.Context, t *testing.T, genReq api.GenerateRequest, anyResp []string) {
 	client, _, cleanup := InitServerConnection(ctx, t)
 	defer cleanup()
-	require.NoError(t, PullIfMissing(ctx, client, genReq.Model))
+	if err := PullIfMissing(ctx, client, genReq.Model); err != nil {
+		t.Fatal(err)
+	}
 	DoGenerate(ctx, t, client, genReq, anyResp, 30*time.Second, 10*time.Second)
 }
 
@@ -509,7 +514,9 @@ func DoGenerate(ctx context.Context, t *testing.T, client *api.Client, genReq ap
 			slog.Warn("model is too large for the target test system", "model", genReq.Model, "error", genErr)
 			return context
 		}
-		require.NoError(t, genErr, "failed with %s request prompt %s ", genReq.Model, genReq.Prompt)
+		if genErr != nil {
+			t.Fatalf("%s failed with %s request prompt %s", genErr, genReq.Model, genReq.Prompt)
+		}
 		// Verify the response contains the expected data
 		response := buf.String()
 		atLeastOne := false
@@ -519,7 +526,9 @@ func DoGenerate(ctx context.Context, t *testing.T, client *api.Client, genReq ap
 				break
 			}
 		}
-		require.True(t, atLeastOne, "%s: none of %v found in %s", genReq.Model, anyResp, response)
+		if !atLeastOne {
+			t.Fatalf("%s: none of %v found in %s", genReq.Model, anyResp, response)
+		}
 		slog.Info("test pass", "model", genReq.Model, "prompt", genReq.Prompt, "contains", anyResp, "response", response)
 	case <-ctx.Done():
 		t.Error("outer test context done while waiting for generate")
@@ -561,17 +570,97 @@ func GenerateRequests() ([]api.GenerateRequest, [][]string) {
 		[][]string{
 			{"sunlight", "scattering", "interact", "color", "surface", "depth", "red", "orange", "yellow", "absorbs", "wavelength"},
 			{"soil", "organic", "earth", "black", "tan", "chemical", "processes", "pigments", "particles", "iron oxide", "rust", "air", "water", "mixture", "mixing"},
-			{"england", "english", "massachusetts", "pilgrims", "colonists", "independence", "british", "feast", "family", "gatherings", "traditions", "turkey", "colonial", "period", "harvest", "agricultural", "european settlers", "american revolution", "civil war", "16th century", "17th century", "native american", "united states"},
+			{"england", "english", "massachusetts", "pilgrims", "colonists", "independence", "british", "feast", "family", "gatherings", "traditions", "turkey", "colonial", "period", "harvest", "agricultural", "european settlers", "american revolution", "civil war", "16th century", "17th century", "native american", "united states", "cultural", "hardship", "autumn", "festival"},
 			{"fourth", "july", "declaration", "independence"},
 			{"nitrogen", "oxygen", "carbon", "dioxide"},
 		}
 }
 
+func DoChat(ctx context.Context, t *testing.T, client *api.Client, req api.ChatRequest, anyResp []string, initialTimeout, streamTimeout time.Duration) *api.Message {
+	stallTimer := time.NewTimer(initialTimeout)
+	var buf bytes.Buffer
+	role := "assistant"
+	fn := func(response api.ChatResponse) error {
+		// fmt.Print(".")
+		role = response.Message.Role
+		buf.Write([]byte(response.Message.Content))
+		if !stallTimer.Reset(streamTimeout) {
+			return errors.New("stall was detected while streaming response, aborting")
+		}
+		return nil
+	}
+
+	stream := true
+	req.Stream = &stream
+	done := make(chan int)
+	var genErr error
+	go func() {
+		genErr = client.Chat(ctx, &req, fn)
+		done <- 0
+	}()
+
+	select {
+	case <-stallTimer.C:
+		if buf.Len() == 0 {
+			t.Errorf("generate never started.  Timed out after :%s", initialTimeout.String())
+		} else {
+			t.Errorf("generate stalled.  Response so far:%s", buf.String())
+		}
+	case <-done:
+		if genErr != nil && strings.Contains(genErr.Error(), "model requires more system memory") {
+			slog.Warn("model is too large for the target test system", "model", req.Model, "error", genErr)
+			return nil
+		}
+		if genErr != nil {
+			t.Fatalf("%s failed with %s request prompt %v", genErr, req.Model, req.Messages)
+		}
+
+		// Verify the response contains the expected data
+		response := buf.String()
+		atLeastOne := false
+		for _, resp := range anyResp {
+			if strings.Contains(strings.ToLower(response), resp) {
+				atLeastOne = true
+				break
+			}
+		}
+		if !atLeastOne {
+			t.Fatalf("%s: none of %v found in \"%s\" -- request was:%v", req.Model, anyResp, response, req.Messages)
+		}
+
+		slog.Info("test pass", "model", req.Model, "messages", req.Messages, "contains", anyResp, "response", response)
+	case <-ctx.Done():
+		t.Error("outer test context done while waiting for generate")
+	}
+	return &api.Message{Role: role, Content: buf.String()}
+}
+
+func ChatRequests() ([]api.ChatRequest, [][]string) {
+	genReqs, results := GenerateRequests()
+	reqs := make([]api.ChatRequest, len(genReqs))
+	// think := api.ThinkValue{Value: "low"}
+	for i := range reqs {
+		reqs[i].Model = genReqs[i].Model
+		reqs[i].Stream = genReqs[i].Stream
+		reqs[i].KeepAlive = genReqs[i].KeepAlive
+		// reqs[i].Think = &think
+		reqs[i].Messages = []api.Message{
+			{
+				Role:    "user",
+				Content: genReqs[i].Prompt,
+			},
+		}
+	}
+	return reqs, results
+}
+
 func skipUnderMinVRAM(t *testing.T, gb uint64) {
 	// TODO use info API in the future
 	if s := os.Getenv("OLLAMA_MAX_VRAM"); s != "" {
 		maxVram, err := strconv.ParseUint(s, 10, 64)
-		require.NoError(t, err)
+		if err != nil {
+			t.Fatal(err)
+		}
 		// Don't hammer on small VRAM cards...
 		if maxVram < gb*format.GibiByte {
 			t.Skip("skipping with small VRAM to avoid timeouts")
@@ -579,6 +668,39 @@ func skipUnderMinVRAM(t *testing.T, gb uint64) {
 	}
 }
 
+// Skip if the target model isn't X% GPU loaded to avoid excessive runtime
+func skipIfNotGPULoaded(ctx context.Context, t *testing.T, client *api.Client, model string, minPercent int) {
+	models, err := client.ListRunning(ctx)
+	if err != nil {
+		t.Fatalf("failed to list running models: %s", err)
+	}
+	loaded := []string{}
+	for _, m := range models.Models {
+		loaded = append(loaded, m.Name)
+		if m.Name != model {
+			continue
+		}
+		gpuPercent := 0
+		switch {
+		case m.SizeVRAM == 0:
+			gpuPercent = 0
+		case m.SizeVRAM == m.Size:
+			gpuPercent = 100
+		case m.SizeVRAM > m.Size || m.Size == 0:
+			t.Logf("unexpected size detected: %d", m.SizeVRAM)
+		default:
+			sizeCPU := m.Size - m.SizeVRAM
+			cpuPercent := math.Round(float64(sizeCPU) / float64(m.Size) * 110)
+			gpuPercent = int(100 - cpuPercent)
+		}
+		if gpuPercent < minPercent {
+			t.Skip(fmt.Sprintf("test requires minimum %d%% GPU load, but model %s only has %d%%", minPercent, model, gpuPercent))
+		}
+		return
+	}
+	t.Skip(fmt.Sprintf("model %s not loaded - actually loaded: %v", model, loaded))
+}
+
 func getTimeouts(t *testing.T) (soft time.Duration, hard time.Duration) {
 	deadline, hasDeadline := t.Deadline()
 	if !hasDeadline {

ml/backend.go

@@ -372,6 +372,7 @@ type Context interface {
 
 	Forward(...Tensor) Context
 	Compute(...Tensor)
+	ComputeWithNotify(func(), ...Tensor) // notify callback once compute has begun
 
 	// Reserve is analogous to Compute but rather than executing a
 	// graph, simply preallocates memory. Typically called with a
@@ -401,6 +402,8 @@ type Tensor interface {
 	Bytes() []byte
 	Floats() []float32
 
+	SetValueFromIntSlice(s []int32)
+
 	Neg(ctx Context) Tensor
 	Add(ctx Context, t2 Tensor) Tensor
 	Sub(ctx Context, t2 Tensor) Tensor

ml/backend/ggml/ggml.go

@@ -82,6 +82,7 @@ type Backend struct {
 	// to the name that is used by the model definition
 	tensorLoadTargets map[string][]string
 
+	schedMu       sync.Mutex // Only one Compute can run at a time
 	sched         C.ggml_backend_sched_t
 	schedBackends []C.ggml_backend_t
 	schedBufts    []C.ggml_backend_buffer_type_t
@@ -758,6 +759,15 @@ func (c *Context) Forward(tensors ...ml.Tensor) ml.Context {
 }
 
 func (c *Context) Compute(tensors ...ml.Tensor) {
+	c.ComputeWithNotify(nil, tensors...)
+}
+
+func (c *Context) ComputeWithNotify(cb func(), tensors ...ml.Tensor) {
+	c.b.schedMu.Lock()
+	defer c.b.schedMu.Unlock()
+	if cb != nil {
+		go cb()
+	}
 	if status := C.ggml_backend_sched_graph_compute_async(c.b.sched, c.graph); status != C.GGML_STATUS_SUCCESS {
 		panic(fmt.Errorf("error computing ggml graph: %v", status))
 	}
@@ -1010,6 +1020,12 @@ func (t *Tensor) Floats() (data []float32) {
 	return
 }
 
+func (t *Tensor) SetValueFromIntSlice(s []int32) {
+	if len(s) > 0 {
+		C.ggml_backend_tensor_set(t.t, unsafe.Pointer(&s[0]), 0, C.ggml_nbytes(t.t))
+	}
+}
+
 func (t *Tensor) DType() ml.DType {
 	switch t.t._type {
 	case C.GGML_TYPE_F32:

model/model.go

@@ -64,7 +64,7 @@ type MultimodalProcessor interface {
 	// This function is also responsible for updating MultimodalHash for any Multimodal
 	// that is modified to ensure that there is a unique hash value that accurately
 	// represents the contents.
-	PostTokenize([]input.Input) ([]input.Input, error)
+	PostTokenize([]*input.Input) ([]*input.Input, error)
 }
 
 // Base implements the common fields and methods for all models
@@ -278,7 +278,7 @@ func canNil(t reflect.Type) bool {
 		t.Kind() == reflect.Slice
 }
 
-func Forward(ctx ml.Context, m Model, inputs []int32, batch input.Batch) (ml.Tensor, error) {
+func Forward(ctx ml.Context, m Model, batch input.Batch) (ml.Tensor, error) {
 	if len(batch.Positions) != len(batch.Sequences) {
 		return nil, fmt.Errorf("length of positions (%v) must match length of seqs (%v)", len(batch.Positions), len(batch.Sequences))
 	}
@@ -287,8 +287,6 @@ func Forward(ctx ml.Context, m Model, inputs []int32, batch input.Batch) (ml.Ten
 		return nil, errors.New("batch size cannot be less than 1")
 	}
 
-	batch.Inputs = ctx.Input().FromIntSlice(inputs, len(inputs))
-
 	cache := m.Config().Cache
 	if cache != nil {
 		err := cache.StartForward(ctx, batch, false)
@@ -302,7 +300,7 @@ func Forward(ctx ml.Context, m Model, inputs []int32, batch input.Batch) (ml.Ten
 		return nil, err
 	}
 
-	ctx.Forward(t).Compute(t)
+	ctx.Forward(t)
 
 	return t, nil
 }

model/models/gemma3/model.go

@@ -112,8 +112,8 @@ func (m *Model) EncodeMultimodal(ctx ml.Context, multimodalData []byte) ([]input
 	return []input.Multimodal{{Tensor: visionOutputs}}, nil
 }
 
-func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
+func (m *Model) PostTokenize(inputs []*input.Input) ([]*input.Input, error) {
-	var result []input.Input
+	var result []*input.Input
 
 	for _, inp := range inputs {
 		if len(inp.Multimodal) == 0 {
@@ -122,17 +122,17 @@ func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
 			inputMultimodal := inp.Multimodal[0].Tensor
 
 			result = append(result,
-				input.Input{Token: 108, SameBatch: inputMultimodal.Dim(1) + 3}, // "\n\n"
+				&input.Input{Token: 108, SameBatch: inputMultimodal.Dim(1) + 3}, // "\n\n"
-				input.Input{Token: 255999},                                     // "<start_of_image>""
+				&input.Input{Token: 255999},                                     // "<start_of_image>""
-				input.Input{Multimodal: []input.Multimodal{{Tensor: inputMultimodal}}, MultimodalHash: inp.MultimodalHash}, // image data is on the first placeholder
+				&input.Input{Multimodal: []input.Multimodal{{Tensor: inputMultimodal}}, MultimodalHash: inp.MultimodalHash}, // image data is on the first placeholder
 			)
 
 			// add image token placeholders
-			result = append(result, slices.Repeat([]input.Input{{Token: 0}}, inputMultimodal.Dim(1)-1)...)
+			result = append(result, slices.Repeat([]*input.Input{{Token: 0}}, inputMultimodal.Dim(1)-1)...)
 
 			result = append(result,
-				input.Input{Token: 256000}, // <end_of_image>
+				&input.Input{Token: 256000}, // <end_of_image>
-				input.Input{Token: 108},    // "\n\n"
+				&input.Input{Token: 108},    // "\n\n"
 			)
 		}
 	}

model/models/llama4/model.go

@@ -134,16 +134,16 @@ type separator struct {
 	y bool
 }
 
-func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
+func (m *Model) PostTokenize(inputs []*input.Input) ([]*input.Input, error) {
-	var result []input.Input
+	var result []*input.Input
 	for _, inp := range inputs {
 		if len(inp.Multimodal) == 0 {
 			result = append(result, inp)
 			continue
 		}
 
-		var imageInputs []input.Input
+		var imageInputs []*input.Input
-		imageInputs = append(imageInputs, input.Input{Token: 200080}) // <|image_start|>
+		imageInputs = append(imageInputs, &input.Input{Token: 200080}) // <|image_start|>
 
 		for i, mm := range inp.Multimodal {
 			patchesPerChunk := mm.Tensor.Dim(1)
@@ -151,20 +151,20 @@ func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
 			if i < len(inp.Multimodal)-1 {
 				separator := mm.Data.(*separator)
 
-				imageInputs = append(imageInputs, input.Input{Token: 200092, Multimodal: []input.Multimodal{{Tensor: mm.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: patchesPerChunk}) // <|patch|>
+				imageInputs = append(imageInputs, &input.Input{Token: 200092, Multimodal: []input.Multimodal{{Tensor: mm.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: patchesPerChunk}) // <|patch|>
-				imageInputs = append(imageInputs, slices.Repeat([]input.Input{{Token: 200092}}, patchesPerChunk-1)...)
+				imageInputs = append(imageInputs, slices.Repeat([]*input.Input{{Token: 200092}}, patchesPerChunk-1)...)
 
 				if separator.x {
-					imageInputs = append(imageInputs, input.Input{Token: 200084}) // <|tile_x_separator|>
+					imageInputs = append(imageInputs, &input.Input{Token: 200084}) // <|tile_x_separator|>
 				}
 				if separator.y {
-					imageInputs = append(imageInputs, input.Input{Token: 200085}) // <|tile_y_separator|>
+					imageInputs = append(imageInputs, &input.Input{Token: 200085}) // <|tile_y_separator|>
 				}
 			} else {
-				imageInputs = append(imageInputs, input.Input{Token: 200090})                                                                                                                      // <|image|>
+				imageInputs = append(imageInputs, &input.Input{Token: 200090})                                                                                                                      // <|image|>
-				imageInputs = append(imageInputs, input.Input{Token: 200092, Multimodal: []input.Multimodal{{Tensor: mm.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: patchesPerChunk}) // <|patch|>
+				imageInputs = append(imageInputs, &input.Input{Token: 200092, Multimodal: []input.Multimodal{{Tensor: mm.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: patchesPerChunk}) // <|patch|>
-				imageInputs = append(imageInputs, slices.Repeat([]input.Input{{Token: 200092}}, patchesPerChunk-1)...)
+				imageInputs = append(imageInputs, slices.Repeat([]*input.Input{{Token: 200092}}, patchesPerChunk-1)...)
-				imageInputs = append(imageInputs, input.Input{Token: 200080}) // <|image_end|>
+				imageInputs = append(imageInputs, &input.Input{Token: 200080}) // <|image_end|>
 			}
 		}
 

model/models/mistral3/model.go

@@ -133,22 +133,22 @@ func (m *Model) EncodeMultimodal(ctx ml.Context, multimodalData []byte) ([]input
 // [IMG]...[IMG][IMG_BREAK][IMG]...[IMG][IMG_BREAK][IMG]...[IMG][IMG_END]
 // Each sequence of [IMG]...[IMG] is a set of patches of vision embeddings
 // that can be processed together.
-func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
+func (m *Model) PostTokenize(inputs []*input.Input) ([]*input.Input, error) {
-	var result []input.Input
+	var result []*input.Input
 	for _, inp := range inputs {
 		if len(inp.Multimodal) == 0 {
 			result = append(result, inp)
 		} else {
 			for i, row := range inp.Multimodal {
 				// [IMG]
-				result = append(result, input.Input{Token: 10, Multimodal: []input.Multimodal{{Tensor: row.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: row.Tensor.Dim(1)})
+				result = append(result, &input.Input{Token: 10, Multimodal: []input.Multimodal{{Tensor: row.Tensor}}, MultimodalHash: inp.MultimodalHash, SameBatch: row.Tensor.Dim(1)})
-				result = append(result, slices.Repeat([]input.Input{{Token: 10}}, row.Tensor.Dim(1)-1)...)
+				result = append(result, slices.Repeat([]*input.Input{{Token: 10}}, row.Tensor.Dim(1)-1)...)
 				if i == len(inp.Multimodal)-1 {
 					// [IMG_END]
-					result = append(result, input.Input{Token: 13})
+					result = append(result, &input.Input{Token: 13})
 				} else {
 					// [IMG_BREAK]
-					result = append(result, input.Input{Token: 12})
+					result = append(result, &input.Input{Token: 12})
 				}
 			}
 		}

model/models/mllama/model.go

@@ -90,7 +90,7 @@ func (m *Model) EncodeMultimodal(ctx ml.Context, multimodalData []byte) ([]input
 	return []input.Multimodal{{Tensor: projectedOutputs}}, nil
 }
 
-func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
+func (m *Model) PostTokenize(inputs []*input.Input) ([]*input.Input, error) {
 	for i := range inputs {
 		if inputs[i].Multimodal != nil {
 			inputs[i].Token = 128256 // <|image|>

model/models/qwen25vl/model.go

@@ -89,8 +89,8 @@ func (m *Model) EncodeMultimodal(ctx ml.Context, multimodalData []byte) ([]input
 }
 
 // PostTokenize arranges Qwen-2.5-VL's inputs for the forward pass
-func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
+func (m *Model) PostTokenize(inputs []*input.Input) ([]*input.Input, error) {
-	var result []input.Input
+	var result []*input.Input
 
 	var (
 		imageToken       int32 = 151655
@@ -112,16 +112,16 @@ func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
 				return nil, fmt.Errorf("failed to encode image prompt: %w", err)
 			}
 			for i := range pre {
-				result = append(result, input.Input{Token: pre[i]})
+				result = append(result, &input.Input{Token: pre[i]})
 			}
 
 			patchesPerChunk := inp.Multimodal[0].Tensor.Dim(1)
 
 			// First add the vision start token
-			result = append(result, input.Input{Token: visionStartToken})
+			result = append(result, &input.Input{Token: visionStartToken})
 
 			// Add the image token with the multimodal tensor data at the first position
-			result = append(result, input.Input{
+			result = append(result, &input.Input{
 				Token:          imageToken,
 				Multimodal:     inp.Multimodal,
 				MultimodalHash: inp.MultimodalHash,
@@ -129,9 +129,9 @@ func (m *Model) PostTokenize(inputs []input.Input) ([]input.Input, error) {
 			})
 
 			// Add the placeholder tokens for the remaining positions (tokensPerGrid-1)
-			result = append(result, slices.Repeat([]input.Input{{Token: imageToken}}, patchesPerChunk-1)...)
+			result = append(result, slices.Repeat([]*input.Input{{Token: imageToken}}, patchesPerChunk-1)...)
 
-			result = append(result, input.Input{Token: visionEndToken})
+			result = append(result, &input.Input{Token: visionEndToken})
 		}
 	}
 

runner/ollamarunner/cache.go

@@ -86,7 +86,7 @@ type InputCacheSlot struct {
 	Id int
 
 	// Inputs that are stored in the KV cache
-	Inputs []input.Input
+	Inputs []*input.Input
 
 	// is this cache actively being processed as part of a sequence?
 	InUse bool
@@ -95,7 +95,7 @@ type InputCacheSlot struct {
 	lastUsed time.Time
 }
 
-func (c *InputCache) LoadCacheSlot(prompt []input.Input) (*InputCacheSlot, []input.Input, error) {
+func (c *InputCache) LoadCacheSlot(prompt []*input.Input) (*InputCacheSlot, []*input.Input, error) {
 	var slot *InputCacheSlot
 	var numPast int32
 	var err error
@@ -146,7 +146,7 @@ func (c *InputCache) LoadCacheSlot(prompt []input.Input) (*InputCacheSlot, []inp
 	return slot, prompt, nil
 }
 
-func (c *InputCache) findLongestCacheSlot(prompt []input.Input) (*InputCacheSlot, int32, error) {
+func (c *InputCache) findLongestCacheSlot(prompt []*input.Input) (*InputCacheSlot, int32, error) {
 	longest := int32(-1)
 	var longestSlot *InputCacheSlot
 
@@ -169,7 +169,7 @@ func (c *InputCache) findLongestCacheSlot(prompt []input.Input) (*InputCacheSlot
 	return longestSlot, longest, nil
 }
 
-func (c *InputCache) findBestCacheSlot(prompt []input.Input) (*InputCacheSlot, int32, error) {
+func (c *InputCache) findBestCacheSlot(prompt []*input.Input) (*InputCacheSlot, int32, error) {
 	oldest := time.Now()
 	var oldestSlot *InputCacheSlot
 
@@ -205,7 +205,7 @@ func (c *InputCache) findBestCacheSlot(prompt []input.Input) (*InputCacheSlot, i
 	if longest > 0 && longestSlot != oldestSlot {
 		slog.Debug("forking cache slot", "src", longestSlot.Id, "dst", oldestSlot.Id, "inputs", longest, "total",
 			len(longestSlot.Inputs))
-		oldestSlot.Inputs = make([]input.Input, longest)
+		oldestSlot.Inputs = make([]*input.Input, longest)
 		copy(oldestSlot.Inputs, longestSlot.Inputs[:longest])
 		if c.cache != nil {
 			c.cache.CopyPrefix(longestSlot.Id, oldestSlot.Id, longest)
@@ -215,7 +215,7 @@ func (c *InputCache) findBestCacheSlot(prompt []input.Input) (*InputCacheSlot, i
 	return oldestSlot, longest, nil
 }
 
-func countCommonPrefix(a []input.Input, b []input.Input) int32 {
+func countCommonPrefix(a []*input.Input, b []*input.Input) int32 {
 	var count int32
 
 	for i := range a {
@@ -250,7 +250,7 @@ func (c *InputCache) ShiftDiscard(inputLen int32, numKeep int32) int32 {
 }
 
 type ErrReprocessInputs struct {
-	Inputs []input.Input
+	Inputs []*input.Input
 }
 
 func (e *ErrReprocessInputs) Error() string {
@@ -283,13 +283,13 @@ func (c *InputCache) ShiftCacheSlot(slot *InputCacheSlot, numKeep int32) error {
 				"id", slot.Id, "error", err)
 
 			// Create new input slice with preserved tokens (numKeep + remaining tokens after discard)
-			newInputs := make([]input.Input, numKeep+inputLen-(numKeep+discard))
+			newInputs := make([]*input.Input, numKeep+inputLen-(numKeep+discard))
 			copy(newInputs[:numKeep], slot.Inputs[:numKeep])
 			copy(newInputs[numKeep:], slot.Inputs[numKeep+discard:])
 
 			// Reset the cache
 			_ = c.cache.Remove(slot.Id, 0, math.MaxInt32)
-			slot.Inputs = []input.Input{}
+			slot.Inputs = []*input.Input{}
 
 			// Return error with inputs that need to be reprocessed
 			return &ErrReprocessInputs{Inputs: newInputs}

runner/ollamarunner/cache_test.go

@@ -13,50 +13,50 @@ import (
 func TestCountCommon(t *testing.T) {
 	tests := []struct {
 		name     string
-		t1       []input.Input
+		t1       []*input.Input
-		t2       []input.Input
+		t2       []*input.Input
 		expected int32
 	}{
 		{
 			name:     "Equal",
-			t1:       []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			t1:       []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
-			t2:       []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			t2:       []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			expected: 3,
 		},
 		{
 			name:     "Prefix",
-			t1:       []input.Input{{Token: 1}},
+			t1:       []*input.Input{{Token: 1}},
-			t2:       []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			t2:       []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			expected: 1,
 		},
 		{
 			name:     "Image Prefix",
-			t1:       []input.Input{{MultimodalHash: 1}},
+			t1:       []*input.Input{{MultimodalHash: 1}},
-			t2:       []input.Input{{MultimodalHash: 1}, {MultimodalHash: 2}, {MultimodalHash: 3}},
+			t2:       []*input.Input{{MultimodalHash: 1}, {MultimodalHash: 2}, {MultimodalHash: 3}},
 			expected: 1,
 		},
 		{
 			name:     "Mixed",
-			t1:       []input.Input{{Token: 1}, {MultimodalHash: 1}},
+			t1:       []*input.Input{{Token: 1}, {MultimodalHash: 1}},
-			t2:       []input.Input{{Token: 1}, {MultimodalHash: 1}, {Token: 5}},
+			t2:       []*input.Input{{Token: 1}, {MultimodalHash: 1}, {Token: 5}},
 			expected: 2,
 		},
 		{
 			name:     "Mixed, Same Length",
-			t1:       []input.Input{{Token: 1}, {MultimodalHash: 1}},
+			t1:       []*input.Input{{Token: 1}, {MultimodalHash: 1}},
-			t2:       []input.Input{{Token: 1}, {MultimodalHash: 2}},
+			t2:       []*input.Input{{Token: 1}, {MultimodalHash: 2}},
 			expected: 1,
 		},
 		{
 			name:     "Empty",
-			t1:       []input.Input{},
+			t1:       []*input.Input{},
-			t2:       []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			t2:       []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			expected: 0,
 		},
 		{
 			name:     "Both Empty",
-			t1:       []input.Input{},
+			t1:       []*input.Input{},
-			t2:       []input.Input{},
+			t2:       []*input.Input{},
 			expected: 0,
 		},
 	}
@@ -80,7 +80,7 @@ func TestFindCacheSlot(t *testing.T) {
 	tests := []struct {
 		name    string
 		cache   InputCache
-		prompt  []input.Input
+		prompt  []*input.Input
 		longest expected
 		best    expected
 	}{
@@ -89,18 +89,18 @@ func TestFindCacheSlot(t *testing.T) {
 			cache: InputCache{slots: []InputCacheSlot{
 				{
 					Id:       0,
-					Inputs:   []input.Input{},
+					Inputs:   []*input.Input{},
 					InUse:    false,
 					lastUsed: time.Time{},
 				},
 				{
 					Id:       1,
-					Inputs:   []input.Input{},
+					Inputs:   []*input.Input{},
 					InUse:    false,
 					lastUsed: time.Time{},
 				},
 			}},
-			prompt:  []input.Input{{Token: 1}},
+			prompt:  []*input.Input{{Token: 1}},
 			longest: expected{result: 0, len: 0},
 			best:    expected{result: 0, len: 0},
 		},
@@ -109,18 +109,18 @@ func TestFindCacheSlot(t *testing.T) {
 			cache: InputCache{slots: []InputCacheSlot{
 				{
 					Id:       0,
-					Inputs:   []input.Input{{Token: 1}},
+					Inputs:   []*input.Input{{Token: 1}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-time.Second),
 				},
 				{
 					Id:       1,
-					Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+					Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-2 * time.Second),
 				},
 			}},
-			prompt:  []input.Input{{Token: 1}, {Token: 2}},
+			prompt:  []*input.Input{{Token: 1}, {Token: 2}},
 			longest: expected{result: 1, len: 2},
 			best:    expected{result: 1, len: 2},
 		},
@@ -129,18 +129,18 @@ func TestFindCacheSlot(t *testing.T) {
 			cache: InputCache{slots: []InputCacheSlot{
 				{
 					Id:       0,
-					Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+					Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-time.Second),
 				},
 				{
 					Id:       1,
-					Inputs:   []input.Input{},
+					Inputs:   []*input.Input{},
 					InUse:    false,
 					lastUsed: time.Time{},
 				},
 			}},
-			prompt:  []input.Input{{Token: 2}},
+			prompt:  []*input.Input{{Token: 2}},
 			longest: expected{result: 0, len: 0},
 			best:    expected{result: 1, len: 0},
 		},
@@ -150,19 +150,19 @@ func TestFindCacheSlot(t *testing.T) {
 				slots: []InputCacheSlot{
 					{
 						Id:       0,
-						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 						InUse:    false,
 						lastUsed: time.Now().Add(-time.Second),
 					},
 					{
 						Id:       1,
-						Inputs:   []input.Input{},
+						Inputs:   []*input.Input{},
 						InUse:    false,
 						lastUsed: time.Time{},
 					},
 				},
 			},
-			prompt:  []input.Input{{Token: 1}},
+			prompt:  []*input.Input{{Token: 1}},
 			longest: expected{result: 0, len: 1},
 			best:    expected{result: 1, len: 1},
 		},
@@ -171,18 +171,18 @@ func TestFindCacheSlot(t *testing.T) {
 			cache: InputCache{slots: []InputCacheSlot{
 				{
 					Id:       0,
-					Inputs:   []input.Input{{Token: 1}},
+					Inputs:   []*input.Input{{Token: 1}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-time.Second),
 				},
 				{
 					Id:       1,
-					Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+					Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-2 * time.Second),
 				},
 			}},
-			prompt:  []input.Input{{Token: 2}, {Token: 3}},
+			prompt:  []*input.Input{{Token: 2}, {Token: 3}},
 			longest: expected{result: 0, len: 0},
 			best:    expected{result: 1, len: 0},
 		},
@@ -191,18 +191,18 @@ func TestFindCacheSlot(t *testing.T) {
 			cache: InputCache{slots: []InputCacheSlot{
 				{
 					Id:       0,
-					Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+					Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 					InUse:    true,
 					lastUsed: time.Now().Add(-time.Second),
 				},
 				{
 					Id:       1,
-					Inputs:   []input.Input{{Token: 1}},
+					Inputs:   []*input.Input{{Token: 1}},
 					InUse:    false,
 					lastUsed: time.Now().Add(-2 * time.Second),
 				},
 			}},
-			prompt:  []input.Input{{Token: 1}, {Token: 2}},
+			prompt:  []*input.Input{{Token: 1}, {Token: 2}},
 			longest: expected{result: 1, len: 1},
 			best:    expected{result: 1, len: 2},
 		},
@@ -300,7 +300,7 @@ func TestLoadCacheSlot(t *testing.T) {
 	tests := []struct {
 		name           string
 		cache          InputCache
-		prompt         []input.Input
+		prompt         []*input.Input
 		wantErr        bool
 		expectedSlotId int
 		expectedPrompt int // expected length of remaining prompt
@@ -312,19 +312,19 @@ func TestLoadCacheSlot(t *testing.T) {
 				slots: []InputCacheSlot{
 					{
 						Id:       0,
-						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 						InUse:    false,
 						lastUsed: time.Now().Add(-time.Second),
 					},
 					{
 						Id:       1,
-						Inputs:   []input.Input{},
+						Inputs:   []*input.Input{},
 						InUse:    false,
 						lastUsed: time.Now().Add(-2 * time.Second),
 					},
 				},
 			},
-			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			prompt:         []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			wantErr:        false,
 			expectedSlotId: 0,
 			expectedPrompt: 1, // Only token 3 remains
@@ -336,19 +336,19 @@ func TestLoadCacheSlot(t *testing.T) {
 				slots: []InputCacheSlot{
 					{
 						Id:       0,
-						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 						InUse:    false,
 						lastUsed: time.Now().Add(-time.Second),
 					},
 					{
 						Id:       1,
-						Inputs:   []input.Input{},
+						Inputs:   []*input.Input{},
 						InUse:    false,
 						lastUsed: time.Now().Add(-2 * time.Second),
 					},
 				},
 			},
-			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			prompt:         []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			wantErr:        false,
 			expectedSlotId: 0,
 			expectedPrompt: 1, // Only token 3 remains
@@ -360,13 +360,13 @@ func TestLoadCacheSlot(t *testing.T) {
 				slots: []InputCacheSlot{
 					{
 						Id:       0,
-						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 						InUse:    false,
 						lastUsed: time.Now().Add(-time.Second),
 					},
 				},
 			},
-			prompt:         []input.Input{{Token: 1}, {Token: 2}},
+			prompt:         []*input.Input{{Token: 1}, {Token: 2}},
 			wantErr:        false,
 			expectedSlotId: 0,
 			expectedPrompt: 1, // Should leave 1 token for sampling
@@ -378,13 +378,13 @@ func TestLoadCacheSlot(t *testing.T) {
 				slots: []InputCacheSlot{
 					{
 						Id:       0,
-						Inputs:   []input.Input{{Token: 1}, {Token: 2}},
+						Inputs:   []*input.Input{{Token: 1}, {Token: 2}},
 						InUse:    true,
 						lastUsed: time.Now().Add(-time.Second),
 					},
 				},
 			},
-			prompt:         []input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
+			prompt:         []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}},
 			wantErr:        true,
 			expectedSlotId: -1,
 			expectedPrompt: -1,
@@ -452,7 +452,7 @@ func TestShiftCacheSlot(t *testing.T) {
 	tests := []struct {
 		name          string
 		numCtx        int32
-		inputs        []input.Input
+		inputs        []*input.Input
 		numKeep       int32
 		cacheErr      bool
 		wantErr       any
@@ -461,7 +461,7 @@ func TestShiftCacheSlot(t *testing.T) {
 		{
 			name:          "Normal shift",
 			numCtx:        10,
-			inputs:        []input.Input{{Token: 1}, {Token: 2}, {Token: 3}, {Token: 4}, {Token: 5}, {Token: 6}, {Token: 7}, {Token: 8}, {Token: 9}, {Token: 10}},
+			inputs:        []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}, {Token: 4}, {Token: 5}, {Token: 6}, {Token: 7}, {Token: 8}, {Token: 9}, {Token: 10}},
 			numKeep:       2,
 			cacheErr:      false, // No error
 			wantErr:       nil,
@@ -470,7 +470,7 @@ func TestShiftCacheSlot(t *testing.T) {
 		{
 			name:          "Cache removal fails",
 			numCtx:        10,
-			inputs:        []input.Input{{Token: 1}, {Token: 2}, {Token: 3}, {Token: 4}, {Token: 5}, {Token: 6}, {Token: 7}, {Token: 8}, {Token: 9}, {Token: 10}},
+			inputs:        []*input.Input{{Token: 1}, {Token: 2}, {Token: 3}, {Token: 4}, {Token: 5}, {Token: 6}, {Token: 7}, {Token: 8}, {Token: 9}, {Token: 10}},
 			numKeep:       2,
 			cacheErr:      true,
 			wantErr:       &ErrReprocessInputs{},
@@ -487,7 +487,7 @@ func TestShiftCacheSlot(t *testing.T) {
 			}
 			slot := &InputCacheSlot{
 				Id:     123,
-				Inputs: make([]input.Input, len(tt.inputs)),
+				Inputs: make([]*input.Input, len(tt.inputs)),
 			}
 			copy(slot.Inputs, tt.inputs)
 

runner/ollamarunner/runner.go

@@ -17,6 +17,7 @@ import (
 	"reflect"
 	"regexp"
 	"runtime"
+	"runtime/debug"
 	"strconv"
 	"strings"
 	"sync"
@@ -51,10 +52,10 @@ type Sequence struct {
 	iBatch int
 
 	// prompt inputs left to evaluate
-	inputs []input.Input
+	inputs []*input.Input
 
 	// inputs that have been added to a batch but not yet submitted to Forward
-	pendingInputs []input.Input
+	pendingInputs []*input.Input
 
 	// tokens that have been generated but not returned yet (e.g. for stop sequences)
 	pendingResponses []string
@@ -182,8 +183,8 @@ func (s *Server) NewSequence(prompt string, images []llm.ImageData, params NewSe
 // inputs processes the prompt and images into a list of inputs
 // by splitting the prompt on [img-<n>] tags, tokenizing text and
 // decoding images
-func (s *Server) inputs(prompt string, images []llm.ImageData) ([]input.Input, []ml.Context, multimodalStore, error) {
+func (s *Server) inputs(prompt string, images []llm.ImageData) ([]*input.Input, []ml.Context, multimodalStore, error) {
-	var inputs []input.Input
+	var inputs []*input.Input
 	var ctxs []ml.Context
 	var mmStore multimodalStore
 
@@ -210,7 +211,7 @@ func (s *Server) inputs(prompt string, images []llm.ImageData) ([]input.Input, [
 		}
 
 		for _, t := range tokens {
-			inputs = append(inputs, input.Input{Token: t})
+			inputs = append(inputs, &input.Input{Token: t})
 		}
 
 		// image - decode and store
@@ -243,7 +244,7 @@ func (s *Server) inputs(prompt string, images []llm.ImageData) ([]input.Input, [
 
 			mmStore.addMultimodal(imageEmbeddings)
 
-			inputs = append(inputs, input.Input{Multimodal: imageEmbeddings, MultimodalHash: imageHash})
+			inputs = append(inputs, &input.Input{Multimodal: imageEmbeddings, MultimodalHash: imageHash})
 			postTokenize = true
 		}
 	}
@@ -259,6 +260,37 @@ func (s *Server) inputs(prompt string, images []llm.ImageData) ([]input.Input, [
 	return inputs, ctxs, mmStore, nil
 }
 
+type batchState struct {
+	// id provides a counter for trace logging batches
+	id int
+
+	// ctx holds the backend context used for this batch
+	ctx ml.Context
+
+	// modelOutput holds the outputs from this batch
+	modelOutput ml.Tensor
+
+	// batchInputs holds the input token pointers which may start as
+	// placeholders later filled in before calling ctx.Compute
+	batchInputs []*input.Input
+
+	// batch contains the inputs for a model forward pass
+	batch input.Batch
+
+	// full set of seqs at the time this batch was initiated
+	seqs []*Sequence
+
+	// Signaled when this batches inputs are ready and compute can proceed
+	inputsReadyCh chan struct{}
+
+	// Signaling when Compute is about to begin on this batch, and
+	// seqs have been updated to prepare for the next batch
+	computeStartedCh chan struct{}
+
+	// Signaled when this batches outputs are complete and the next batch can proceed
+	outputsReadyCh chan struct{}
+}
+
 type Server struct {
 	// modelPath is the location of the model to be loaded
 	modelPath string
@@ -290,6 +322,12 @@ type Server struct {
 	// TODO (jmorganca): make this n_batch
 	batchSize int
 
+	// Used to signal a hard failure during async processing which will panic the runner
+	hardErrCh chan error
+
+	// Simple counter used only for trace logging batches
+	batchID int
+
 	// protects access to everything below this line
 	// this is context state needed for decoding
 	mu sync.Mutex
@@ -362,33 +400,66 @@ func (s *Server) removeSequence(seqIndex int, reason llm.DoneReason) {
 	s.seqsSem.Release(1)
 }
 
+// track batch state between forwardBatch, computeBatch and predictForwardBatch
+
 func (s *Server) run(ctx context.Context) {
 	s.ready.Wait()
 
+	var activeBatch batchState
 	for {
 		select {
 		case <-ctx.Done():
 			return
+		case err := <-s.hardErrCh:
+			panic(err)
 		default:
-			err := s.processBatch()
+			var err error
+			activeBatch, err = s.forwardBatch(activeBatch)
 			if err != nil {
 				panic(err)
 			}
+			go s.computeBatch(activeBatch)
 		}
 	}
 }
 
-func (s *Server) processBatch() error {
+// forwardBatch will calculate a batch.
+func (s *Server) forwardBatch(pendingBatch batchState) (nextBatch batchState, err error) {
+	// If we have a pending batch still processing, wait until Compute has started
+	// before setting up the next batch so the seqs inputs are ready to receive their
+	// token values and we get the correct input pointers for the batchInputs
+	if pendingBatch.ctx != nil {
+		slog.Log(context.TODO(), logutil.LevelTrace, "forwardBatch waiting for compute to start", "pendingBatch.id", pendingBatch.id)
+		<-pendingBatch.computeStartedCh
+		slog.Log(context.TODO(), logutil.LevelTrace, "forwardBatch compute started, setting up next batch", "pendingBatch.id", pendingBatch.id, "id", s.batchID)
+		nextBatch.inputsReadyCh = pendingBatch.outputsReadyCh // Chain the ouputs from the pending batch to the next inputs batch
+	} else {
+		slog.Log(context.TODO(), logutil.LevelTrace, "forwardBatch no pending batch detected", "batchID", s.batchID)
+		// No pendingBatch, so the inputs will be ready in the seqs immediately
+		nextBatch.inputsReadyCh = make(chan struct{}, 1)
+		nextBatch.inputsReadyCh <- struct{}{}
+	}
+
 	s.mu.Lock()
 	for s.allNil() {
 		s.cond.Wait() // Wait until an item is added
 	}
 	defer s.mu.Unlock()
 
-	ctx := s.model.Backend().NewContext()
+	nextBatch.ctx = s.model.Backend().NewContext()
-	defer ctx.Close()
+	defer func() {
+		if err != nil {
+			nextBatch.ctx.Close()
+			nextBatch.ctx = nil
+		}
+	}()
+	nextBatch.id = s.batchID
+	nextBatch.seqs = append([]*Sequence{}, s.seqs...)
+	nextBatch.computeStartedCh = make(chan struct{}, 1)
+	nextBatch.outputsReadyCh = make(chan struct{}, 1)
 
-	var batchInputs []int32
+	// Prepare the seqs and batch, but defer the input token values as we may not be ready yet
+	var batchInputs []*input.Input
 	var batch input.Batch
 
 	resumeSeq := -1
@@ -396,7 +467,6 @@ func (s *Server) processBatch() error {
 	for range s.seqs {
 		seqIdx = (seqIdx + 1) % len(s.seqs)
 		seq := s.seqs[seqIdx]
-
 		if seq == nil {
 			continue
 		}
@@ -404,12 +474,13 @@ func (s *Server) processBatch() error {
 		// if past the num predict limit
 		if seq.numPredict > 0 && seq.numPredicted >= seq.numPredict {
 			s.removeSequence(seqIdx, llm.DoneReasonLength)
+			nextBatch.seqs[seqIdx] = nil
 			continue
 		}
 
 		if !s.cache.enabled {
 			seq.inputs = append(seq.cache.Inputs, seq.inputs...)
-			seq.cache.Inputs = []input.Input{}
+			seq.cache.Inputs = []*input.Input{}
 		}
 
 		batchSize := s.batchSize
@@ -442,25 +513,28 @@ func (s *Server) processBatch() error {
 					break
 				}
 
-				err := s.cache.ShiftCacheSlot(seq.cache, seq.numKeep)
+				err = s.cache.ShiftCacheSlot(seq.cache, seq.numKeep)
 				if err != nil {
 					var reprocess *ErrReprocessInputs
 					if errors.As(err, &reprocess) {
 						// Prepend these inputs to the sequence's inputs queue for reprocessing
 						seq.inputs = append(reprocess.Inputs, seq.inputs...)
 						// Skip this sequence but continue processing the rest
+						nextBatch.seqs[seqIdx] = nil // clear this sequence for this batch
+						err = nil
 						continue
 					} else {
-						return err
+						return
 					}
 				}
 			}
 
-			batchInputs = append(batchInputs, inp.Token)
+			batchInputs = append(batchInputs, seq.inputs[i])
 			if inp.Multimodal != nil {
-				mm, err := seq.mmStore.getMultimodal(s.model.Backend(), ctx, inp.Multimodal, false)
+				var mm []input.Multimodal
+				mm, err = seq.mmStore.getMultimodal(s.model.Backend(), nextBatch.ctx, inp.Multimodal, false)
 				if err != nil {
-					return err
+					return
 				}
 				batch.Multimodal = append(batch.Multimodal, input.MultimodalIndex{Index: len(batchInputs) - 1, Multimodal: mm})
 			}
@@ -472,6 +546,7 @@ func (s *Server) processBatch() error {
 			if i+1 == len(seq.inputs) {
 				batch.Outputs = append(batch.Outputs, int32(len(batchInputs)-1))
 			}
+			slog.Log(context.TODO(), logutil.LevelTrace, "forwardBatch iBatch", "batchID", s.batchID, "seqIdx", seqIdx, "seq.iBatch", seq.iBatch, "i+1", i+1, "len(seq.inputs)", len(seq.inputs))
 			seq.pendingInputs = append(seq.pendingInputs, inp)
 		}
 
@@ -485,36 +560,129 @@ func (s *Server) processBatch() error {
 	}
 
 	if len(batchInputs) == 0 {
-		return nil
+		slog.Log(context.TODO(), logutil.LevelTrace, "forwardBatch no batchInputs, going idle", "batchID", s.batchID)
+		nextBatch.ctx.Close()
+		nextBatch.ctx = nil
+		return
 	}
+	s.batchID++
 
-	modelOutput, err := model.Forward(ctx, s.model, batchInputs, batch)
+	// Actual batchInputs values will be injected into the batch.Inputs tensor before calling Compute
+	batch.Inputs = nextBatch.ctx.Input().Empty(ml.DTypeI32, len(batchInputs))
+	nextBatch.modelOutput, err = model.Forward(nextBatch.ctx, s.model, batch)
 	if err != nil {
-		return fmt.Errorf("failed to decode batch: %w", err)
+		err = fmt.Errorf("failed to build graph: %w", err)
+		return
+	}
+	nextBatch.batchInputs = batchInputs
+	nextBatch.batch = batch
+
+	return
+}
+
+// Async processing of the next batch
+func (s *Server) computeBatch(activeBatch batchState) {
+	if activeBatch.ctx == nil {
+		// Nothing to compute
+		return
+	}
+	defer activeBatch.ctx.Close()
+
+	// Wait until inputs are ready
+	slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: waiting for inputs to be ready", "batchID", activeBatch.id)
+	<-activeBatch.inputsReadyCh
+	slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: inputs are ready", "batchID", activeBatch.id)
+
+	// Once we complete, signal the next batch of inputs are ready
+	// This will unblock the next computeBatch, or forwardBatch if new seqs come in
+	defer func() {
+		slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: outputs are ready", "batchID", activeBatch.id)
+		activeBatch.outputsReadyCh <- struct{}{}
+	}()
+
+	s.mu.Lock()
+
+	// Gather the actual input token values now that they're ready
+	batchInputs := make([]int32, len(activeBatch.batchInputs))
+	for i := range batchInputs {
+		batchInputs[i] = activeBatch.batchInputs[i].Token
 	}
 
-	logits := modelOutput.Floats()
+	// Now we run part of the decoding algorithm to adjust the seq.inputs with placeholder tokens
-
+	// so that forwardBatch can build a batchInputs set which will eventually contain the actual
+	// decoded tokens.
+	nextBatchTokens := make([]*input.Input, len(s.seqs))
+	iBatches := make([]int, len(s.seqs)) // Record the iBatch values before releasing the lock
 	for i, seq := range s.seqs {
+		iBatches[i] = -1
 		if seq == nil {
 			continue
 		}
+		// Skip over any newly added or skipped sequences
+		if activeBatch.seqs[i] == nil {
+			continue
+		}
 
-		// After calling Forward, pending inputs are now in the cache
+		// Detect if the sequence we're processing has already been completed and replaced
+		// with a new sequence
+		if seq != activeBatch.seqs[i] {
+			slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: sequence replaced, discarding its results", "batchID", activeBatch.id, "seqIdx", i)
+			continue
+		}
+
+		// Pending inputs will actually be in the cache after we call Compute.
+		// However, we have already resolved any placeholder tokens.
+		//
+		// It's possible for incoming sequences to look at the values that we've
+		// added to the cache here and start relying on them before we've done
+		// the computation. This is OK as long as we ensure that this batch's
+		// computation happens before any future batch's and we never fail
+		// (unless we take down the whole runner).
 		if len(seq.pendingInputs) > 0 {
 			seq.cache.Inputs = append(seq.cache.Inputs, seq.pendingInputs...)
-			seq.pendingInputs = []input.Input{}
+			seq.pendingInputs = []*input.Input{}
 		}
 
 		// don't sample prompt processing
 		if len(seq.inputs) != 0 {
 			if !s.cache.enabled {
-				return errors.New("caching disabled but unable to fit entire input in a batch")
+				s.hardErrCh <- fmt.Errorf("caching disabled but unable to fit entire input in a batch")
+				s.mu.Unlock()
+				return
 			}
 			continue
 		}
 
 		seq.numPredicted++
+		nextToken := &input.Input{Token: 0} // placeholder we'll fill in after Compute/Floats
+		seq.inputs = []*input.Input{nextToken}
+		nextBatchTokens[i] = nextToken
+		iBatches[i] = seq.iBatch
+	}
+
+	// At this point the seqs are ready for forwardBatch to move forward so unblock
+	s.mu.Unlock()
+
+	activeBatch.batch.Inputs.SetValueFromIntSlice(batchInputs)
+	activeBatch.ctx.ComputeWithNotify(
+		func() {
+			slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: signaling computeStartedCh", "batchID", activeBatch.id)
+			activeBatch.computeStartedCh <- struct{}{}
+		},
+		activeBatch.modelOutput)
+	logits := activeBatch.modelOutput.Floats()
+
+	slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: logits ready", "batchID", activeBatch.id)
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: decoding", "batchID", activeBatch.id)
+	for i, seq := range s.seqs {
+		if seq == nil || nextBatchTokens[i] == nil {
+			continue
+		}
+
 		if seq.numPredicted == 1 {
 			seq.startGenerationTime = time.Now()
 		}
@@ -522,36 +690,38 @@ func (s *Server) processBatch() error {
 		// if done processing the prompt, generate an embedding and return
 		if seq.embeddingOnly {
 			// TODO(jessegross): Embedding support
-			slog.Warn("generation of embedding outputs not yet supported")
+			slog.Warn("generation of embedding outputs not yet supported", "id", activeBatch.id, "seqIdx", i)
 			s.removeSequence(i, llm.DoneReasonStop)
 			continue
 		}
 
 		// sample a token
-		vocabSize := len(logits) / len(batch.Outputs)
+		vocabSize := len(logits) / len(activeBatch.batch.Outputs)
-
+		slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: vocab details", "batchID", activeBatch.id, "seqIdx", i, "len(logits)", len(logits), "len(activeBatch.batch.Outputs)", len(activeBatch.batch.Outputs), "vocabSize", vocabSize, "iBatches", iBatches)
-		token, err := seq.sampler.Sample(logits[seq.iBatch*vocabSize : (seq.iBatch+1)*vocabSize])
+		token, err := seq.sampler.Sample(logits[iBatches[i]*vocabSize : (iBatches[i]+1)*vocabSize])
 		if err != nil {
-			return fmt.Errorf("failed to sample token: %w", err)
+			s.hardErrCh <- fmt.Errorf("failed to sample token: %w", err)
+			return
 		}
 
+		nextBatchTokens[i].Token = token
+
 		// if it's an end of sequence token, break
 		if s.model.(model.TextProcessor).Is(token, model.SpecialEOS) {
 			// TODO (jmorganca): we should send this back
 			// as it's important for the /api/generate context
 			// seq.responses <- piece
-
+			slog.Log(context.TODO(), logutil.LevelTrace, "computeBatch: EOS", "batchID", activeBatch.id, "seqIdx", i)
 			s.removeSequence(i, llm.DoneReasonStop)
 			continue
 		}
 
 		piece, err := s.model.(model.TextProcessor).Decode([]int32{token})
 		if err != nil {
-			return err
+			s.hardErrCh <- fmt.Errorf("failed to decode token: %w", err)
+			return
 		}
 
-		seq.inputs = []input.Input{{Token: token}}
-
 		seq.pendingResponses = append(seq.pendingResponses, piece)
 		sequence := strings.Join(seq.pendingResponses, "")
 
@@ -575,6 +745,7 @@ func (s *Server) processBatch() error {
 			if tokenTruncated || origLen == newLen {
 				tokenLen--
 			}
+
 			seq.cache.Inputs = seq.cache.Inputs[:tokenLen]
 
 			s.removeSequence(i, llm.DoneReasonStop)
@@ -593,8 +764,6 @@ func (s *Server) processBatch() error {
 			s.removeSequence(i, llm.DoneReasonConnectionClosed)
 		}
 	}
-
-	return nil
 }
 
 func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
@@ -736,7 +905,10 @@ func (s *Server) reserveWorstCaseGraph() error {
 	defer ctx.Close()
 
 	var err error
-	inputs := make([]input.Input, s.batchSize)
+	inputs := make([]*input.Input, s.batchSize)
+	for i := range inputs {
+		inputs[i] = &input.Input{}
+	}
 	mmStore := newMultimodalStore()
 
 	// Multimodal strategy:
@@ -778,8 +950,11 @@ func (s *Server) reserveWorstCaseGraph() error {
 			}
 
 			if len(inputs) < s.batchSize {
-				newInputs := make([]input.Input, s.batchSize)
+				newInputs := make([]*input.Input, s.batchSize)
 				copy(newInputs, inputs)
+				for i := len(inputs); i < s.batchSize; i++ {
+					newInputs[i] = &input.Input{}
+				}
 				inputs = newInputs
 			}
 		}
@@ -842,6 +1017,7 @@ func (s *Server) allocModel(
 	// Convert memory allocation panics to errors
 	defer func() {
 		if r := recover(); r != nil {
+			debug.PrintStack()
 			if err, ok := r.(error); ok {
 				panicErr = err
 			} else {
@@ -1011,6 +1187,7 @@ func Execute(args []string) error {
 	server := &Server{
 		modelPath: *mpath,
 		status:    llm.ServerStatusLaunched,
+		hardErrCh: make(chan error, 1),
 	}
 
 	server.cond = sync.NewCond(&server.mu)