ollama/llama/runner/runner.go
Jesse Gross 65973ceb64 runner.go: Make KV entry accounting more robust
The structure of the accounting for KV cache shifting was carried
over from the old runner but it now doesn't feel natural with the new
runner. There are a number of invariants that should hold true but
are difficult to reason about. There is at least one bug report
that would imply that the invariants are not holding.

This reduces the number of implicit assumptions and is more forgiving
of unexpected situations. It also improves behavior around which input
tokens are kept when truncation occurs.

Bug #7545
2024-11-11 20:23:03 -08:00

907 lines
23 KiB
Go

package main
import (
"context"
"encoding/json"
"errors"
"flag"
"fmt"
"log"
"log/slog"
"net"
"net/http"
"os"
"path/filepath"
"regexp"
"runtime"
"strconv"
"strings"
"sync"
"time"
"unicode/utf8"
"github.com/ollama/ollama/api"
"github.com/ollama/ollama/llama"
)
// input is an element of the prompt to process, either
// a token or an image embedding (generated from a vision projector)
type input struct {
token int
// embed is an image embedding
embed []float32
}
type Sequence struct {
// batch index
iBatch int
// number of tokens predicted so far
numPredicted int
// prompt inputs left to evaluate
inputs []input
// tokens that have been generated but not returned yet (e.g. for stop sequences)
pendingResponses []string
// input cache being used by this sequence
cache *InputCacheSlot
// does this sequence require cross-attention layers to be processed? - if we have seen
// an image for certain multi-modal models
crossAttention bool
// channel to send responses over
responses chan string
// channel to stop decoding (such as if the remote connection is closed)
quit chan bool
// number of tokens to predict
numPredict int
samplingCtx *llama.SamplingContext
// channel to send back the embedding if embedding only
embedding chan []float32
// stop sequences
stop []string
// number of inputs to keep at the beginning when shifting context window
numKeep int
// true if an embedding are to be returned instead of text generation
embeddingOnly bool
doneReason string
// Metrics
startProcessingTime time.Time
startGenerationTime time.Time
numDecoded int
numPromptInputs int
}
type NewSequenceParams struct {
numPredict int
stop []string
numKeep int
samplingParams *llama.SamplingParams
embedding bool
}
func (s *Server) NewSequence(prompt string, images []ImageData, params NewSequenceParams) (*Sequence, error) {
s.ready.Wait()
startTime := time.Now()
inputs, err := s.inputs(prompt, images)
if err != nil {
return nil, fmt.Errorf("failed to process inputs: %w", err)
} else if len(inputs) == 0 {
return nil, errors.New("no input provided")
}
if params.numKeep < 0 {
params.numKeep = len(inputs)
}
if s.model.AddBOSToken() {
params.numKeep += 1
}
// Ensure that at least 1 input can be discarded during shift
params.numKeep = min(params.numKeep, s.cache.numCtx-1)
if len(inputs) > s.cache.numCtx {
slog.Warn("input exceeds context length", "prompt", len(inputs), "limit", s.cache.numCtx)
}
var sc *llama.SamplingContext
if params.samplingParams != nil {
sc, err = llama.NewSamplingContext(s.model, *params.samplingParams)
if err != nil {
return nil, err
}
for _, input := range inputs {
if input.embed == nil {
sc.Accept(input.token, false)
}
}
}
return &Sequence{
inputs: inputs,
numPromptInputs: len(inputs),
startProcessingTime: startTime,
numPredict: params.numPredict,
pendingResponses: make([]string, 0),
responses: make(chan string, 100),
quit: make(chan bool, 1),
embedding: make(chan []float32, 1),
samplingCtx: sc,
embeddingOnly: params.embedding,
stop: params.stop,
numKeep: params.numKeep,
}, nil
}
// inputs processes the prompt and images into a list of inputs
// by splitting the prompt on [img-<n>] tags, tokenizing text and
// generating image embeddings for each image
func (s *Server) inputs(prompt string, images []ImageData) ([]input, error) {
var inputs []input
re := regexp.MustCompile(`\[img-(\d+)\]`)
parts := re.Split(prompt, -1)
matches := re.FindAllStringSubmatch(prompt, -1)
for i, part := range parts {
// text - tokenize
if strings.TrimSpace(part) != "" {
tokens, err := s.lc.Model().Tokenize(part, i == 0, true)
if err != nil {
return nil, err
}
for _, t := range tokens {
inputs = append(inputs, input{token: t})
}
}
// image - generate image embedding
if i < len(matches) {
n, _ := strconv.Atoi(matches[i][1])
imageIndex := -1
for j := range images {
if images[j].ID == n {
imageIndex = j
break
}
}
if imageIndex < 0 {
return nil, fmt.Errorf("invalid image index: %d", n)
}
embed, err := s.image.NewEmbed(s.lc, images[imageIndex].Data, images[imageIndex].AspectRatioID)
if err != nil {
return nil, err
}
for _, e := range embed {
inputs = append(inputs, input{embed: e})
}
}
}
return inputs, nil
}
type Server struct {
model *llama.Model
lc *llama.Context
// required for image embeddings
image *ImageContext
// TODO (jmorganca): make this n_batch
batchSize int
// parallel is the number of parallel requests to handle
parallel int
// seqs is the list of parallel sequences being evaluated
// TODO (jmorganca): this can probably be moved into run()
seqs []*Sequence
// KV cache
cache *InputCache
// next sequence for prompt processing to avoid starvation
nextSeq int
// is the server ready to process requests?
ready sync.WaitGroup
mu sync.Mutex
cond *sync.Cond
progress float32
status ServerStatus
}
func (s *Server) allNil() bool {
for _, item := range s.seqs {
if item != nil {
return false
}
}
return true
}
func flushPending(seq *Sequence) bool {
joined := strings.Join(seq.pendingResponses, "")
seq.pendingResponses = []string{}
// Check if there are any partial UTF-8 characters remaining.
// We already check and queue as we are generating but some may
// still make it here:
// - Sequence is ending, e.g. generation limit has been hit
// - Invalid characters in the middle of a string
// This is a stricter check to ensure we never output invalid Unicode.
for !utf8.ValidString(joined) {
joined = joined[:len(joined)-1]
}
if len(joined) == 0 {
return true
}
select {
case seq.responses <- joined:
return true
case <-seq.quit:
return false
}
}
func (s *Server) removeSequence(seqIndex int, reason string) {
seq := s.seqs[seqIndex]
flushPending(seq)
seq.doneReason = reason
close(seq.responses)
close(seq.embedding)
seq.cache.InUse = false
s.seqs[seqIndex] = nil
}
func (s *Server) run(ctx context.Context) {
s.ready.Wait()
// Logically these batches are used only within the context of processBatch
// but it is better for performance to allocate them once here
tokenBatch, err := llama.NewBatch(s.batchSize, len(s.seqs), 0)
if err != nil {
panic(err)
}
defer tokenBatch.Free()
var embedBatch *llama.Batch
embedBatchSize := s.image.BatchSize(s.batchSize)
if embedBatchSize != 0 {
embedBatch, err = llama.NewBatch(embedBatchSize, len(s.seqs), s.image.EmbedSize(s.lc))
if err != nil {
panic(err)
}
defer embedBatch.Free()
} else {
embedBatch = &llama.Batch{}
}
for {
select {
case <-ctx.Done():
return
default:
s.processBatch(tokenBatch, embedBatch)
tokenBatch.Clear()
embedBatch.Clear()
}
}
}
// TODO (jmorganca): processBatch should be simplified, removing:
// * sampling
// * stop token checking
// * metrics
// these should instead be handled by the handlers
// it should only be responsible for accepting tokens or embeddings and
// processing batches as fast as possible
func (s *Server) processBatch(tokenBatch *llama.Batch, embedBatch *llama.Batch) {
s.mu.Lock()
for s.allNil() {
s.cond.Wait() // Wait until an item is added
}
defer s.mu.Unlock()
var batch *llama.Batch
crossAttention := false
seqIdx := s.nextSeq - 1
for range s.seqs {
seqIdx = (seqIdx + 1) % len(s.seqs)
seq := s.seqs[seqIdx]
if seq == nil {
continue
}
// if past the num predict limit
if seq.numPredict > 0 && seq.numPredicted > seq.numPredict {
s.removeSequence(seqIdx, "limit")
continue
}
var numInputsProcessed int
shifted := false
for i, input := range seq.inputs {
if len(seq.cache.Inputs)+1 > s.cache.numCtx {
if !shifted {
s.cache.ShiftCacheSlot(seq.cache, seq.numKeep)
shifted = true
} else {
break
}
}
embedding := input.embed != nil
// If we don't currently have a batch, use one of the correct type and
// fill it up as much as possible across all sequences. If we encounter an
// input of the opppsite type, stop for that sequence but then pick up from
// there for the next batch, ensuring that we alternate types
if batch == nil {
if !embedding {
batch = tokenBatch
} else {
batch = embedBatch
seq.crossAttention = s.image.NeedCrossAttention(input)
}
} else if embedding != batch.IsEmbedding() || crossAttention != seq.crossAttention {
s.nextSeq = seqIdx
break
}
if i >= batch.Size() {
break
}
crossAttention = seq.crossAttention
batch.Add(input.token, input.embed, len(seq.cache.Inputs), i+1 == len(seq.inputs), seq.cache.Id)
seq.cache.Inputs = append(seq.cache.Inputs, input)
numInputsProcessed++
}
if numInputsProcessed > 0 {
seq.inputs = seq.inputs[numInputsProcessed:]
seq.iBatch = batch.NumTokens() - 1
}
}
if batch == nil || batch.NumTokens() == 0 {
return
}
s.lc.SetCrossAttention(crossAttention)
err := s.lc.Decode(batch)
if err != nil {
slog.Error("failed to decode batch", "error", err)
return
}
for i, seq := range s.seqs {
if seq == nil {
continue
}
// don't sample prompt processing
if len(seq.inputs) != 0 {
continue
}
seq.numDecoded += 1
if seq.numDecoded == 1 {
seq.startGenerationTime = time.Now()
}
// if done processing the prompt, generate an embedding and return
if seq.embeddingOnly {
embed := s.lc.GetEmbeddingsSeq(i)
if embed == nil {
embed = s.lc.GetEmbeddingsIth(seq.iBatch)
}
seq.embedding <- embed
s.removeSequence(i, "")
continue
}
// sample a token
token := seq.samplingCtx.Sample(s.lc, seq.iBatch)
seq.samplingCtx.Accept(token, true)
piece := s.model.TokenToPiece(token)
seq.numPredicted++
// if it's an end of sequence token, break
if s.model.TokenIsEog(token) {
// TODO (jmorganca): we should send this back
// as it's important for the /api/generate context
// seq.responses <- piece
s.removeSequence(i, "stop")
continue
}
seq.inputs = []input{{token: token}}
seq.pendingResponses = append(seq.pendingResponses, piece)
sequence := strings.Join(seq.pendingResponses, "")
if ok, stop := findStop(sequence, seq.stop); ok {
slog.Debug("hit stop token", "pending", seq.pendingResponses, "stop", stop)
var tokenTruncated bool
origLen := len(seq.pendingResponses)
seq.pendingResponses, tokenTruncated = truncateStop(seq.pendingResponses, stop)
newLen := len(seq.pendingResponses)
// Update the cache based on the tokens that will be returned:
// - We have 1 token more than is currently in the cache because
// the last one generated wasn't submitted to Decode
// - Remove any stop sequences that we stripped out
// - If truncateStop removed a portion of a token, drop that
// - As defense-in-depth, if truncatedToken didn't find a stop token
// remove the extra one that we added to the cache len
tokenLen := len(seq.cache.Inputs) + 1
tokenLen -= origLen - newLen
if tokenTruncated || origLen == newLen {
tokenLen--
}
seq.cache.Inputs = seq.cache.Inputs[:tokenLen]
s.removeSequence(i, "stop")
continue
}
if containsStopSuffix(sequence, seq.stop) {
continue
}
if incompleteUnicode(sequence) {
continue
}
if !flushPending(seq) {
s.removeSequence(i, "connection")
}
}
}
// TODO (jmorganca): use structs from the api package to avoid duplication
// this way the api acts as a proxy instead of using a different api for the
// runner
type Options struct {
api.Runner
NumKeep int `json:"n_keep"`
Seed int `json:"seed"`
NumPredict int `json:"n_predict"`
TopK int `json:"top_k"`
TopP float32 `json:"top_p"`
MinP float32 `json:"min_p"`
TFSZ float32 `json:"tfs_z"`
TypicalP float32 `json:"typical_p"`
RepeatLastN int `json:"repeat_last_n"`
Temperature float32 `json:"temperature"`
RepeatPenalty float32 `json:"repeat_penalty"`
PresencePenalty float32 `json:"presence_penalty"`
FrequencyPenalty float32 `json:"frequency_penalty"`
Mirostat int `json:"mirostat"`
MirostatTau float32 `json:"mirostat_tau"`
MirostatEta float32 `json:"mirostat_eta"`
PenalizeNewline bool `json:"penalize_nl"`
Stop []string `json:"stop"`
}
type ImageData struct {
Data []byte `json:"data"`
ID int `json:"id"`
AspectRatioID int `json:"aspect_ratio_id"`
}
type CompletionRequest struct {
Prompt string `json:"prompt"`
Images []ImageData `json:"image_data"`
Grammar string `json:"grammar"`
CachePrompt bool `json:"cache_prompt"`
Options
}
type Timings struct {
PredictedN int `json:"predicted_n"`
PredictedMS float64 `json:"predicted_ms"`
PromptN int `json:"prompt_n"`
PromptMS float64 `json:"prompt_ms"`
}
type CompletionResponse struct {
Content string `json:"content"`
Stop bool `json:"stop"`
Model string `json:"model,omitempty"`
Prompt string `json:"prompt,omitempty"`
StoppedLimit bool `json:"stopped_limit,omitempty"`
PredictedN int `json:"predicted_n,omitempty"`
PredictedMS float64 `json:"predicted_ms,omitempty"`
PromptN int `json:"prompt_n,omitempty"`
PromptMS float64 `json:"prompt_ms,omitempty"`
Timings Timings `json:"timings"`
}
func (s *Server) completion(w http.ResponseWriter, r *http.Request) {
var req CompletionRequest
req.Options = Options(api.DefaultOptions())
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
http.Error(w, "Bad request", http.StatusBadRequest)
return
}
// Set the headers to indicate streaming
w.Header().Set("Content-Type", "application/json")
w.Header().Set("Transfer-Encoding", "chunked")
flusher, ok := w.(http.Flusher)
if !ok {
http.Error(w, "Streaming not supported", http.StatusInternalServerError)
return
}
var samplingParams llama.SamplingParams
samplingParams.TopK = req.TopK
samplingParams.TopP = req.TopP
samplingParams.MinP = req.MinP
samplingParams.TfsZ = req.TFSZ
samplingParams.TypicalP = req.TypicalP
samplingParams.Temp = req.Temperature
samplingParams.RepeatLastN = req.RepeatLastN
samplingParams.PenaltyRepeat = req.RepeatPenalty
samplingParams.PenaltyFreq = req.FrequencyPenalty
samplingParams.PenaltyPresent = req.PresencePenalty
samplingParams.Mirostat = req.Mirostat
samplingParams.MirostatTau = req.MirostatTau
samplingParams.MirostatEta = req.MirostatEta
samplingParams.PenalizeNl = req.PenalizeNewline
samplingParams.Seed = uint32(req.Seed)
samplingParams.Grammar = req.Grammar
seq, err := s.NewSequence(req.Prompt, req.Images, NewSequenceParams{
numPredict: req.NumPredict,
stop: req.Stop,
numKeep: req.NumKeep,
samplingParams: &samplingParams,
embedding: false,
})
if err != nil {
http.Error(w, fmt.Sprintf("Failed to create new sequence: %v", err), http.StatusInternalServerError)
return
}
// TODO (jmorganca): add to sequence queue instead of
// failing if a slot isn't available
s.mu.Lock()
for i, sq := range s.seqs {
if sq == nil {
seq.cache, seq.inputs, err = s.cache.LoadCacheSlot(seq.inputs, req.CachePrompt)
if err != nil {
s.mu.Unlock()
http.Error(w, fmt.Sprintf("Failed to load cache: %v", err), http.StatusInternalServerError)
return
}
seq.crossAttention = s.image.NeedCrossAttention(seq.cache.Inputs...)
s.seqs[i] = seq
s.cond.Signal()
break
}
}
s.mu.Unlock()
for {
select {
case <-r.Context().Done():
close(seq.quit)
return
case content, ok := <-seq.responses:
if ok {
if err := json.NewEncoder(w).Encode(&CompletionResponse{
Content: content,
}); err != nil {
http.Error(w, fmt.Sprintf("failed to encode response: %v", err), http.StatusInternalServerError)
close(seq.quit)
return
}
flusher.Flush()
} else {
// Send the final response
if err := json.NewEncoder(w).Encode(&CompletionResponse{
Stop: true,
StoppedLimit: seq.doneReason == "limit",
Timings: Timings{
PromptN: seq.numPromptInputs,
PromptMS: float64(seq.startGenerationTime.Sub(seq.startProcessingTime).Milliseconds()),
PredictedN: seq.numDecoded,
PredictedMS: float64(time.Since(seq.startGenerationTime).Milliseconds()),
},
}); err != nil {
http.Error(w, fmt.Sprintf("failed to encode final response: %v", err), http.StatusInternalServerError)
}
return
}
}
}
}
type EmbeddingRequest struct {
Content string `json:"content"`
CachePrompt bool `json:"cache_prompt"`
}
type EmbeddingResponse struct {
Embedding []float32 `json:"embedding"`
}
func (s *Server) embeddings(w http.ResponseWriter, r *http.Request) {
var req EmbeddingRequest
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
http.Error(w, fmt.Sprintf("bad request: %s", err), http.StatusBadRequest)
return
}
w.Header().Set("Content-Type", "application/json")
slog.Debug("embedding request", "content", req.Content)
seq, err := s.NewSequence(req.Content, nil, NewSequenceParams{embedding: true})
if err != nil {
http.Error(w, fmt.Sprintf("Failed to create new sequence: %v", err), http.StatusInternalServerError)
return
}
// TODO (jessegross): Wait for a free slot instead of failing and blocking forever
s.mu.Lock()
for i, sq := range s.seqs {
if sq == nil {
seq.cache, seq.inputs, err = s.cache.LoadCacheSlot(seq.inputs, req.CachePrompt)
if err != nil {
s.mu.Unlock()
http.Error(w, fmt.Sprintf("Failed to load cache: %v", err), http.StatusInternalServerError)
return
}
s.seqs[i] = seq
s.cond.Signal()
break
}
}
s.mu.Unlock()
embedding := <-seq.embedding
if err := json.NewEncoder(w).Encode(&EmbeddingResponse{
Embedding: embedding,
}); err != nil {
http.Error(w, fmt.Sprintf("failed to encode response: %v", err), http.StatusInternalServerError)
}
}
type HealthResponse struct {
Status string `json:"status"`
Progress float32 `json:"progress"`
}
type ServerStatus int
const (
ServerStatusReady ServerStatus = iota
ServerStatusLoadingModel
ServerStatusError
)
func (s ServerStatus) ToString() string {
switch s {
case ServerStatusReady:
return "ok"
case ServerStatusLoadingModel:
return "loading model"
default:
return "server error"
}
}
func (s *Server) health(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(&HealthResponse{
Status: s.status.ToString(),
Progress: s.progress,
}); err != nil {
http.Error(w, fmt.Sprintf("failed to encode response: %v", err), http.StatusInternalServerError)
}
}
func (s *Server) loadModel(
params llama.ModelParams,
mpath string,
lpath string,
ppath string,
kvSize int,
flashAttention bool,
threads int,
multiUserCache bool,
) {
llama.BackendInit()
var err error
s.model, err = llama.LoadModelFromFile(mpath, params)
if err != nil {
panic(err)
}
ctxParams := llama.NewContextParams(kvSize, s.batchSize*s.parallel, s.parallel, threads, flashAttention)
s.lc, err = llama.NewContextWithModel(s.model, ctxParams)
if err != nil {
panic(err)
}
if lpath != "" {
err := s.model.ApplyLoraFromFile(s.lc, lpath, 1.0, threads)
if err != nil {
panic(err)
}
}
if ppath != "" {
var err error
s.image, err = NewImageContext(s.lc, ppath)
if err != nil {
panic(err)
}
}
s.cache, err = NewInputCache(s.lc, kvSize, s.parallel, multiUserCache)
if err != nil {
panic(err)
}
s.status = ServerStatusReady
s.ready.Done()
}
func main() {
mpath := flag.String("model", "", "Path to model binary file")
ppath := flag.String("mmproj", "", "Path to projector binary file")
parallel := flag.Int("parallel", 1, "Number of sequences to handle simultaneously")
batchSize := flag.Int("batch-size", 512, "Batch size")
nGpuLayers := flag.Int("n-gpu-layers", 0, "Number of layers to offload to GPU")
mainGpu := flag.Int("main-gpu", 0, "Main GPU")
flashAttention := flag.Bool("flash-attn", false, "Enable flash attention")
kvSize := flag.Int("ctx-size", 2048, "Context (or KV cache) size")
lpath := flag.String("lora", "", "Path to lora layer file")
port := flag.Int("port", 8080, "Port to expose the server on")
threads := flag.Int("threads", runtime.NumCPU(), "Number of threads to use during generation")
verbose := flag.Bool("verbose", false, "verbose output (default: disabled)")
noMmap := flag.Bool("no-mmap", false, "do not memory-map model (slower load but may reduce pageouts if not using mlock)")
mlock := flag.Bool("mlock", false, "force system to keep model in RAM rather than swapping or compressing")
tensorSplit := flag.String("tensor-split", "", "fraction of the model to offload to each GPU, comma-separated list of proportions")
multiUserCache := flag.Bool("multiuser-cache", false, "optimize input cache algorithm for multiple users")
requirements := flag.Bool("requirements", false, "print json requirement information")
flag.Parse()
if *requirements {
printRequirements(os.Stdout)
return
}
level := slog.LevelInfo
if *verbose {
level = slog.LevelDebug
}
handler := slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{
Level: level,
AddSource: true,
ReplaceAttr: func(_ []string, attr slog.Attr) slog.Attr {
if attr.Key == slog.SourceKey {
source := attr.Value.Any().(*slog.Source)
source.File = filepath.Base(source.File)
}
return attr
},
})
slog.SetDefault(slog.New(handler))
slog.Info("starting go runner")
slog.Info("system", "info", llama.PrintSystemInfo(), "threads", *threads)
server := &Server{
batchSize: *batchSize,
parallel: *parallel,
seqs: make([]*Sequence, *parallel),
status: ServerStatusLoadingModel,
}
var tensorSplitFloats []float32
if *tensorSplit != "" {
stringFloats := regexp.MustCompile(",").Split(*tensorSplit, -1)
tensorSplitFloats = make([]float32, 0, len(stringFloats))
for _, s := range stringFloats {
f, _ := strconv.ParseFloat(s, 32)
tensorSplitFloats = append(tensorSplitFloats, float32(f))
}
}
params := llama.ModelParams{
NumGpuLayers: *nGpuLayers,
MainGpu: *mainGpu,
UseMmap: !*noMmap && *lpath == "",
UseMlock: *mlock,
TensorSplit: tensorSplitFloats,
Progress: func(progress float32) {
server.progress = progress
},
}
server.ready.Add(1)
go server.loadModel(params, *mpath, *lpath, *ppath, *kvSize, *flashAttention, *threads, *multiUserCache)
server.cond = sync.NewCond(&server.mu)
ctx, cancel := context.WithCancel(context.Background())
go server.run(ctx)
addr := "127.0.0.1:" + strconv.Itoa(*port)
listener, err := net.Listen("tcp", addr)
if err != nil {
fmt.Println("Listen error:", err)
return
}
defer listener.Close()
mux := http.NewServeMux()
mux.HandleFunc("/embedding", server.embeddings)
mux.HandleFunc("/completion", server.completion)
mux.HandleFunc("/health", server.health)
httpServer := http.Server{
Handler: mux,
}
log.Println("Server listening on", addr)
if err := httpServer.Serve(listener); err != nil {
log.Fatal("server error:", err)
}
cancel()
}