sleepy/llama.cpp
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server : speculative checkpointing (#19493)

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* server : speculative decoding using checkpoints

* server : fix draft check with checkpoints

* server : rename spec vars

* server : log levels

* server : refactored spec logic to speculative.cpp

* server : renamed spec checkpoints option

* server : fix spec checkpoints, logging

* speculative : checkpoints with draft model, logging

* server : n_tokens_cur and create_checkpoint in draft

* server : fix server_speculative_callback (slot.id)

* spec : fix ngram-map/begin idx_last_check

* spec : init ckpt (begin() wasn't called)

* chore: update webui build output

* server : restore sampler in spec checkpoint and clear mem

* cont : avoid --spec-use-checkpoints argument

* cont : remove server_prompt_checkpoint_with_size

* spec : rename (leave_draft_state)

* cont : clean-up

* cont : do not ignore partial drafts even if the are short

* cont : spec callback owned by session

* cont : simplify

* cont : avoid empty speculative session

* cont : simplify

* cont : simplify

* cont : enable mtmd speculative decoding

* cont : keep the spec sampler alive

* cont : simplify

* cont : fix nullptr deref + draft checkpoints

* cont : remove common_speculative_accept_response

* cont : remove callback

* cont : simplify

* cont : minor

* cont : simplify

* cont : fix accepted number

---------

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
This commit is contained in:
Sascha Rogmann
2026-04-19 09:24:06 +02:00
committed by GitHub
parent 91fef95362
commit 455d8e4be8
10 changed files with 421 additions and 180 deletions
Download Patch File Download Diff File Expand all files Collapse all files
common/chat.cpp
+1 -1
View File
@@ -2334,7 +2334,7 @@ common_chat_msg common_chat_peg_parse(const common_peg_arena & src_pars
? input
: params.generation_prompt + input;
LOG_DBG("Parsing PEG input with format %s: %s\n", common_chat_format_name(params.format), effective_input.c_str());
//LOG_DBG("Parsing PEG input with format %s: %s\n", common_chat_format_name(params.format), effective_input.c_str());
common_peg_parse_flags flags = COMMON_PEG_PARSE_FLAG_LENIENT;
if (params.debug) {
common/common.h
+2 -2
View File
@@ -11,7 +11,6 @@
#include <sstream>
#include <string>
#include <string_view>
#include <variant>
#include <vector>
#include <map>
@@ -303,7 +302,7 @@ struct common_params_speculative {
// general-purpose speculative decoding parameters
int32_t n_max = 16; // maximum number of tokens to draft during speculative decoding
int32_t n_min = 0; // minimum number of draft tokens to use for speculative decoding
int32_t n_min = 0; // minimum number of draft tokens to use for speculative decoding
float p_split = 0.1f; // speculative decoding split probability
float p_min = 0.75f; // minimum speculative decoding probability (greedy)
@@ -312,6 +311,7 @@ struct common_params_speculative {
uint16_t ngram_size_n = 12; // ngram size for lookup
uint16_t ngram_size_m = 48; // mgram size for speculative tokens
uint16_t ngram_min_hits = 1; // minimum hits at ngram/mgram lookup for mgram to be proposed
bool use_checkpoints = false; // use checkpoints to rewind in token history of recurrent models
std::shared_ptr<common_ngram_mod> ngram_mod;
common/ngram-map.cpp
+4 -4
View File
@@ -208,7 +208,7 @@ void common_ngram_map_begin(
count_keys, count_keys_del, count_values_del, count_map_entries_upd);
}
map.idx_last_check = (map.size_last_begin > 0) ? map.size_last_begin - 1 : 0;
map.idx_last_check = size_begin;
map.size_last_begin = size_begin;
}
@@ -231,7 +231,7 @@ void common_ngram_map_draft(common_ngram_map & map,
GGML_ABORT("%s: cur_len exceeds UINT32_MAX: %zu", __func__, cur_len);
}
if (map.idx_last_check > cur_len) {
if (map.idx_last_check > cur_len) {
// Should not happen because of common_ngram_map_begin().
GGML_ABORT("%s: map.idx_last_check > cur_len: %zu > %zu", __func__, map.idx_last_check, cur_len);
}
@@ -386,7 +386,7 @@ void common_ngram_map_draft(common_ngram_map & map,
LOG_DBG("%s: key_idx = %zu, key_offset = %zu, key_num = %d, draft.size = %zu\n", __func__,
curr_key.key_idx, key_offset, curr_key.key_num, draft.size());
map.last_draft_created = false;
map.last_draft_created = true;
map.last_draft_key_idx = key_offset;
map.last_draft_value_idx = 0; // value 0 is used for simple mode
return;
@@ -524,7 +524,7 @@ void common_ngram_map_accept(common_ngram_map & map, uint16_t n_accepted) {
struct common_ngram_map_value & curr_value = curr_key.values[val_idx]; // value used for draft generation.
// update the value statistics
LOG_INF("common_ngram_map_send_accepted: n_accepted = %d, prev value_num = %d\n",
LOG_DBG("common_ngram_map_send_accepted: n_accepted = %d, prev value_num = %d\n",
n_accepted, curr_value.n_accepted);
curr_value.n_accepted = n_accepted;
}
common/speculative.cpp
+139 -23
View File
@@ -13,6 +13,7 @@
#include <cstring>
#include <iomanip>
#include <map>
#include <cinttypes>
#define SPEC_VOCAB_MAX_SIZE_DIFFERENCE 128
#define SPEC_VOCAB_CHECK_START_TOKEN_ID 5
@@ -144,10 +145,28 @@ struct common_speculative_state {
virtual void accept(uint16_t n_accepted) = 0;
};
struct common_speculative_checkpoint {
llama_pos pos_min = 0;
llama_pos pos_max = 0;
int64_t n_tokens = 0;
std::vector<uint8_t> data;
size_t size() const {
return data.size();
}
size_t ckpt_size = 0;
};
struct common_speculative_state_draft : public common_speculative_state {
llama_context * ctx_tgt; // only used for retokenizing from ctx_dft
llama_context * ctx_dft;
struct common_speculative_checkpoint ckpt;
bool use_checkpoint;
common_sampler * smpl;
llama_batch batch;
@@ -160,10 +179,12 @@ struct common_speculative_state_draft : public common_speculative_state {
enum common_speculative_type type,
llama_context * ctx_tgt,
llama_context * ctx_dft,
const std::vector<std::pair<std::string, std::string>> & replacements)
const std::vector<std::pair<std::string, std::string>> & replacements,
bool use_checkpoint)
: common_speculative_state(type)
, ctx_tgt(ctx_tgt)
, ctx_dft(ctx_dft)
, use_checkpoint(use_checkpoint)
{
batch = llama_batch_init(llama_n_batch(ctx_dft), 0, 1);
smpl = nullptr;
@@ -218,7 +239,48 @@ struct common_speculative_state_draft : public common_speculative_state {
}
void begin(const llama_tokens & prompt) override {
GGML_UNUSED(prompt);
if (use_checkpoint && ckpt.size() > 0) {
// delete checkpoint
LOG_DBG("%s: delete checkpoint, prompt.size=%zu, pos_min=%d, pos_max=%d, n_tokens=%" PRId64 ", size=%.3f MiB\n",
__func__, prompt.size(), ckpt.pos_min, ckpt.pos_max, ckpt.n_tokens, (float) ckpt.data.size() / 1024 / 1024);
ckpt.pos_min = 0;
ckpt.pos_max = 0;
ckpt.n_tokens = 0;
ckpt.ckpt_size = 0;
ckpt.data.clear();
}
}
size_t draft_create_checkpoint(int n_tokens_prompt, int n_tokens_batch) {
int slot_id = 0;
const size_t checkpoint_size = llama_state_seq_get_size_ext(ctx_dft, slot_id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
ckpt.pos_min = llama_memory_seq_pos_min(llama_get_memory(ctx_dft), slot_id);
ckpt.pos_max = llama_memory_seq_pos_max(llama_get_memory(ctx_dft), slot_id);
ckpt.n_tokens = n_tokens_prompt - n_tokens_batch;
ckpt.data.resize(checkpoint_size);
const size_t n = llama_state_seq_get_data_ext(ctx_dft, ckpt.data.data(), checkpoint_size, slot_id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
if (n != checkpoint_size) {
GGML_ABORT("checkpoint size mismatch: expected %zu, got %zu\n", checkpoint_size, n);
}
LOG_DBG("%s: pos_min = %d, pos_max = %d, size = %.3f MiB\n", __func__,
ckpt.pos_min, ckpt.pos_max, (float) ckpt.data.size() / 1024 / 1024);
return n;
}
size_t draft_restore_checkpoint(size_t ckpt_size_part_expected) {
int slot_id = 0;
LOG_DBG("%s: pos_min = %d, pos_max = %d\n", __func__, ckpt.pos_min, ckpt.pos_max);
const size_t n = llama_state_seq_set_data_ext(ctx_dft, ckpt.data.data(), ckpt.size(), slot_id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
if (n != ckpt_size_part_expected) {
GGML_ABORT("%s: failed to restore context checkpoint (pos_min=%d, pos_max=%d, size=%zu, get_data_ext->%zu, set_data_ext->%zu",
__func__, ckpt.pos_min, ckpt.pos_max, ckpt.size(), ckpt_size_part_expected, n);
}
llama_memory_seq_rm(llama_get_memory(ctx_dft), slot_id, ckpt.pos_max + 1, -1);
return n;
}
void draft(
@@ -236,8 +298,8 @@ struct common_speculative_state_draft : public common_speculative_state {
auto * mem_dft = llama_get_memory(ctx_dft);
int reuse_i = 0;
int reuse_n = 0;
int reuse_i = 0; // index of part to be reused in prompt_dft
int reuse_n = 0; // length of part to be reused in prompt_dft
const int n_ctx = llama_n_ctx(ctx_dft) - params.n_max;
@@ -287,18 +349,26 @@ struct common_speculative_state_draft : public common_speculative_state {
}
}
LOG_DBG("%s: reuse_i = %d, reuse_n = %d, prompt = %d\n", __func__, reuse_i, reuse_n, (int) prompt_dft.size());
LOG_DBG("%s: reuse_i = %d, reuse_n = %d, #prompt_dft = %zu, #prompt_cur = %zu\n",
__func__, reuse_i, reuse_n, prompt_dft.size(), prompt_cur.size());
if (use_checkpoint && ckpt.ckpt_size == 0 && reuse_n > 0) {
LOG_DBG("%s: no checkpoint available, no reuse, (reuse_i=%d, reuse_n=%d) -> (0, 0)\n",
__func__, reuse_i, reuse_n);
reuse_i = 0;
reuse_n = 0;
}
result.clear();
result.reserve(params.n_max);
if (reuse_n == 0) {
bool needs_ckpt = use_checkpoint && prompt_dft.size() > 0;
if (reuse_n == 0 || (use_checkpoint && reuse_i > 0)) {
llama_memory_clear(mem_dft, false);
prompt_dft.clear();
} else {
// this happens when a previous draft has been discarded (for example, due to being too small), but the
// target model agreed with it. in this case, we simply pass back the previous results to save compute
if (reuse_i + reuse_n < (int) prompt_dft.size() && prompt_dft[reuse_i + reuse_n] == id_last) {
if (reuse_i + reuse_n < (int64_t) prompt_dft.size() && prompt_dft[reuse_i + reuse_n] == id_last) {
for (int i = reuse_i + reuse_n + 1; i < (int) prompt_dft.size(); ++i) {
result.push_back(prompt_dft[i]);
@@ -310,19 +380,50 @@ struct common_speculative_state_draft : public common_speculative_state {
return;
}
bool do_restore = false;
if (prompt_dft.size() > prompt_cur.size() && reuse_i + reuse_n < (int64_t) prompt_dft.size()) {
// This can happen after a partial acceptance (speculative decoding with checkpoints)
LOG_DBG("%s: #prompt_dft=%zu, #prompt_cur=%zu, shorten draft\n",
__func__, prompt_dft.size(), prompt_cur.size());
prompt_dft.resize(prompt_cur.size());
do_restore = true;
}
if (reuse_i > 0) {
llama_memory_seq_rm (mem_dft, 0, 0, reuse_i);
bool is_removed = llama_memory_seq_rm (mem_dft, 0, 0, reuse_i);
if (!is_removed) {
LOG_ERR("%s: llama_memory_seq_rm failed, reuse_i=%d\n", __func__, reuse_i);
}
llama_memory_seq_add(mem_dft, 0, reuse_i, -1, -reuse_i);
prompt_dft.erase(prompt_dft.begin(), prompt_dft.begin() + reuse_i);
}
if (reuse_n < (int) prompt_dft.size()) {
llama_memory_seq_rm (mem_dft, 0, reuse_n, -1);
prompt_dft.erase(prompt_dft.begin() + reuse_n, prompt_dft.end());
if (reuse_n < (int) prompt_dft.size() || do_restore) {
if (use_checkpoint) {
if (ckpt.n_tokens > (int64_t) prompt_dft.size()) {
LOG_INF("%s: checkpoint is too large, prompt_tgt.size=%zu, ckpt.n_tokens=%" PRId64 ", reuse_n=%d, prompt_dft.size=%zu\n",
__func__, prompt_tgt.size(), ckpt.n_tokens, reuse_n, prompt_dft.size());
}
draft_restore_checkpoint(ckpt.ckpt_size);
reuse_n = ckpt.n_tokens;
prompt_dft.resize(reuse_n);
needs_ckpt = false;
} else {
bool is_removed = llama_memory_seq_rm (mem_dft, 0, reuse_n, -1);
if (!is_removed) {
LOG_ERR("%s: llama_memory_seq_rm failed, reuse_n=%d, prompt_dft.size=%zu\n",
__func__, reuse_n, prompt_dft.size());
}
prompt_dft.erase(prompt_dft.begin() + reuse_n, prompt_dft.end());
}
}
}
if (needs_ckpt) {
ckpt.ckpt_size = draft_create_checkpoint(prompt_dft.size(), batch.n_tokens);
}
// prepare a batch to evaluate any new tokens in the prompt
common_batch_clear(batch);
@@ -337,7 +438,11 @@ struct common_speculative_state_draft : public common_speculative_state {
if (batch.n_tokens > 0) {
//LOG_DBG("%s: draft prompt batch: %s\n", __func__, string_from(ctx, batch).c_str());
llama_decode(ctx_dft, batch);
int ret = llama_decode(ctx_dft, batch);
if (ret != 0 && ret != 1) {
LOG_WRN("%s: llama_decode returned %d, prompt_cur.size=%zu\n",
__func__, ret, prompt_cur.size());
}
}
const llama_pos n_past = prompt_dft.size();
@@ -351,7 +456,11 @@ struct common_speculative_state_draft : public common_speculative_state {
LOG_DBG("%s: draft prompt: %s\n", __func__, string_from(ctx_dft, prompt_dft).c_str());
llama_decode(ctx_dft, batch);
int ret = llama_decode(ctx_dft, batch);
if (ret != 0 && ret != 1) {
LOG_WRN("%s: llama_decode returned %d, prompt_cur.size=%zu, prompt_dft.size=%zu\n",
__func__, ret, prompt_cur.size(), prompt_dft.size());
}
common_sampler_reset(smpl);
@@ -387,7 +496,11 @@ struct common_speculative_state_draft : public common_speculative_state {
common_batch_add(batch, id, n_past + i + 1, { 0 }, true);
// evaluate the drafted tokens on the draft model
llama_decode(ctx_dft, batch);
ret = llama_decode(ctx_dft, batch);
if (ret != 0) {
LOG_WRN("%s: llama_decode[%d] returned %d, prompt_cur.size=%zu, prompt_dft.size=%zu\n",
__func__, i, ret, prompt_cur.size(), prompt_dft.size());
}
prompt_dft.push_back(id);
}
@@ -739,6 +852,7 @@ struct common_speculative_state_ngram_cache : public common_speculative_state {
struct common_speculative {
std::vector<std::unique_ptr<common_speculative_state>> impls; // list of implementations to use and their states
common_speculative_state * curr_impl = nullptr; // current implementation in use (for stats)
};
@@ -798,13 +912,13 @@ enum common_speculative_type common_speculative_type_from_name(const std::string
return it->second;
}
bool common_speculative_is_compat(llama_context * ctx_tgt) {
common_speculative_compat_type common_speculative_is_compat(llama_context * ctx_tgt) {
auto * mem = llama_get_memory(ctx_tgt);
if (mem == nullptr) {
return false;
return COMMON_SPECULATIVE_COMPAT_TYPE_NO;
}
bool res = true;
common_speculative_compat_type res = COMMON_SPECULATIVE_COMPAT_TYPE_FULL;
llama_memory_clear(mem, true);
@@ -816,14 +930,14 @@ bool common_speculative_is_compat(llama_context * ctx_tgt) {
int ret = llama_decode(ctx_tgt, llama_batch_get_one(tmp.data(), tmp.size()));
if (ret != 0) {
LOG_ERR("%s: llama_decode() failed: %d\n", __func__, ret);
res = false;
res = COMMON_SPECULATIVE_COMPAT_TYPE_NO;
goto done;
}
// try to remove the last tokens
if (!llama_memory_seq_rm(mem, 0, 1, -1)) {
LOG_WRN("%s: the target context does not support partial sequence removal\n", __func__);
res = false;
res = COMMON_SPECULATIVE_COMPAT_TYPE_CKPT;
goto done;
}
@@ -909,9 +1023,10 @@ common_speculative * common_speculative_init(
break;
case COMMON_SPECULATIVE_TYPE_DRAFT: {
impls.push_back(std::make_unique<common_speculative_state_draft>(config.type,
/* .ctx_tgt = */ ctx_tgt,
/* .ctx_dft = */ ctx_dft,
/* .replacements = */ params.replacements
/* .ctx_tgt = */ ctx_tgt,
/* .ctx_dft = */ ctx_dft,
/* .replacements = */ params.replacements,
/* .use_checkpoint= */ params.use_checkpoints // TODO: this should be based on the draft model!
));
break;
}
@@ -966,7 +1081,8 @@ common_speculative * common_speculative_init(
}
auto * result = new common_speculative {
/* .impls = */ std::move(impls)
/* .impls = */ std::move(impls),
/* .curr_impl = */ nullptr,
};
return result;
common/speculative.h
+13 -1
View File
@@ -14,9 +14,15 @@ enum common_speculative_type common_speculative_type_from_name(const std::string
// convert type to string
std::string common_speculative_type_to_str(enum common_speculative_type type);
enum common_speculative_compat_type {
COMMON_SPECULATIVE_COMPAT_TYPE_NO = 0,
COMMON_SPECULATIVE_COMPAT_TYPE_FULL = 1,
COMMON_SPECULATIVE_COMPAT_TYPE_CKPT = 2,
};
// check if the llama_context is compatible for speculative decoding
// note: clears the memory of the context
bool common_speculative_is_compat(llama_context * ctx_tgt);
common_speculative_compat_type common_speculative_is_compat(llama_context * ctx_tgt);
common_speculative * common_speculative_init(
common_params_speculative & params,
@@ -39,3 +45,9 @@ void common_speculative_accept(common_speculative * spec, uint16_t n_accepted);
// print statistics about the speculative decoding
void common_speculative_print_stats(const common_speculative * spec);
struct common_speculative_deleter {
void operator()(common_speculative * s) { common_speculative_free(s); }
};
typedef std::unique_ptr<common_speculative, common_speculative_deleter> common_speculative_ptr;
tools/server/server-common.cpp
+13 -3
View File
@@ -391,15 +391,25 @@ void server_tokens::push_back(server_tokens & tokens) {
}
void server_tokens::insert(const llama_tokens & inp_tokens) {
GGML_ASSERT(!has_mtmd); // only allow this if mtmd is disabled
tokens.insert(tokens.end(), inp_tokens.begin(), inp_tokens.end());
}
const llama_tokens & server_tokens::get_text_tokens() const {
GGML_ASSERT(!has_mtmd); // only allow this if mtmd is disabled
const llama_tokens & server_tokens::get_tokens() const {
GGML_ASSERT(!has_mtmd);
return tokens;
}
llama_tokens server_tokens::get_text_tokens() const {
llama_tokens res;
res.reserve(tokens.size());
for (llama_token t : tokens) {
if (t != LLAMA_TOKEN_NULL) {
res.push_back(t);
}
}
return res;
}
void server_tokens::set_token(llama_pos pos, llama_token id) {
GGML_ASSERT(!has_mtmd); // only allow this if mtmd is disabled
tokens[pos] = id;
tools/server/server-common.h
+3 -1
View File
@@ -190,7 +190,9 @@ public:
void insert(const llama_tokens & inp_tokens);
// for compatibility with speculative decoding, ctx shift, slot save/load
const llama_tokens & get_text_tokens() const;
const llama_tokens & get_tokens() const;
llama_tokens get_text_tokens() const;
// for compatibility with speculative decoding
void set_token(llama_pos pos, llama_token id);
tools/server/server-context.cpp
+232 -144
View File
@@ -1,3 +1,4 @@
#include "server-context.h"
#include "server-common.h"
#include "server-http.h"
@@ -19,6 +20,7 @@
#include <exception>
#include <memory>
#include <filesystem>
#include <utility>
// fix problem with std::min and std::max
#if defined(_WIN32)
@@ -33,6 +35,31 @@ using json = nlohmann::ordered_json;
constexpr int HTTP_POLLING_SECONDS = 1;
static server_prompt_checkpoint server_get_checkpoint(llama_context * ctx, int id, int64_t n_tokens, llama_pos pos_min = -1, llama_pos pos_max = -1) {
if (pos_min == -1) {
pos_min = llama_memory_seq_pos_min(llama_get_memory(ctx), id);
}
if (pos_max == -1) {
pos_max = llama_memory_seq_pos_max(llama_get_memory(ctx), id);
}
const size_t checkpoint_size = llama_state_seq_get_size_ext(ctx, id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
auto cur = server_prompt_checkpoint {
/*.pos_min = */ pos_min,
/*.pos_max = */ pos_max,
/*.n_tokens = */ n_tokens,
/*.data = */ std::vector<uint8_t>(checkpoint_size),
};
const size_t n = llama_state_seq_get_data_ext(ctx, cur.data.data(), checkpoint_size, id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
if (n != checkpoint_size) {
GGML_ABORT("checkpoint size mismatch: expected %zu, got %zu\n", checkpoint_size, n);
}
return cur;
}
// state diagram: https://github.com/ggml-org/llama.cpp/pull/9283
enum slot_state {
SLOT_STATE_IDLE,
@@ -57,7 +84,12 @@ struct server_slot {
// multimodal
mtmd_context * mctx = nullptr;
common_speculative * spec = nullptr;
// speculative decoding
llama_tokens spec_draft;
std::vector<int32_t> spec_i_batch;
server_prompt_checkpoint spec_ckpt;
common_speculative_ptr spec;
// TODO: move members that belong to the task (such as `generated_text`, `has_new_line`) to task_results_state
// see https://github.com/ggml-org/llama.cpp/pull/18283#issuecomment-3710175837
@@ -83,11 +115,6 @@ struct server_slot {
std::string debug_generated_text;
llama_tokens generated_tokens;
// idx of draft tokens in the main batch
// non-empty if we went to evaluate draft tokens
// ref: https://github.com/ggml-org/llama.cpp/pull/17808
std::vector<int32_t> i_batch_dft;
std::vector<completion_token_output> generated_token_probs;
bool has_next_token = true;
@@ -147,8 +174,7 @@ struct server_slot {
common_sampler_ptr smpl;
llama_token sampled; // in speculative mode, this is the last accepted token
llama_tokens drafted;
llama_token sampled; // in speculative mode, this is the last accepted token
// stats
size_t n_sent_text = 0; // number of sent text character
@@ -178,8 +204,11 @@ struct server_slot {
stopping_word = "";
n_sent_text = 0;
drafted.clear();
i_batch_dft.clear();
if (can_speculate()) {
spec_draft.clear();
spec_i_batch.clear();
spec_ckpt.clear();
}
generated_tokens.clear();
generated_token_probs.clear();
json_schema = json();
@@ -300,6 +329,85 @@ struct server_slot {
return n_draft_max;
}
void update_batch(llama_batch & batch) {
const int n_draft_max = get_n_draft_max();
if (n_draft_max > 0) {
GGML_ASSERT(can_speculate());
// generate draft tokens in speculative decoding mode
// TODO: rework to have a single draft llama_context shared across all slots [TAG_SERVER_SPEC_REWORK]
// perform the speculative drafting for all sequences at the same time in a single batch
const llama_tokens & tokens = prompt.tokens.get_text_tokens();
const auto & params_spec = task->params.speculative;
if (!spec_draft.empty()) {
// we have a previous (partial) draft to reuse
if (task->params.speculative.use_checkpoints) {
GGML_ASSERT(!spec_ckpt.empty());
}
} else {
GGML_ASSERT(spec_i_batch.empty());
// generate a new draft
spec_draft = common_speculative_draft(spec.get(), params_spec, tokens, sampled);
if (spec_draft.size() > (size_t) n_draft_max) {
SLT_WRN(*this, "draft size %d exceeds max %d, truncating\n", (int) spec_draft.size(), n_draft_max);
spec_draft.resize(n_draft_max);
}
if (spec_draft.size() < (size_t) params_spec.n_min) {
SLT_DBG(*this, "ignoring small draft: %d < %d\n", (int) spec_draft.size(), params_spec.n_min);
spec_draft.clear();
}
if (!spec_draft.empty() && params_spec.use_checkpoints) {
const auto n_tokens = prompt.tokens.size();
auto & ckpt = spec_ckpt;
ckpt = server_get_checkpoint(ctx, this->id, n_tokens);
SLT_DBG(*this, "created speculative checkpoint (pos_min = %d, pos_max = %d, n_tokens = %zu, size = %.3f MiB)\n",
ckpt.pos_min, ckpt.pos_max, n_tokens, (float) ckpt.data.size() / 1024 / 1024);
}
}
GGML_ASSERT(spec_draft.size() <= (size_t) n_draft_max);
}
if (spec_draft.empty()) {
// no speculative decoding
i_batch = batch.n_tokens;
common_batch_add(batch, sampled, prompt.tokens.pos_next(), { this->id }, true);
SLT_DBG(*this, "slot decode token, id=%d, n_ctx = %d, n_tokens = %d, truncated = %d\n",
sampled, n_ctx, prompt.n_tokens(), truncated);
} else {
SLT_DBG(*this, "generate_draft: id=%d, #tokens=%zu, #draft=%zu, pos_next=%d\n",
sampled, prompt.tokens.size(), spec_draft.size(), prompt.tokens.pos_next());
GGML_ASSERT(spec_i_batch.empty());
spec_i_batch.push_back(batch.n_tokens);
for (size_t i = 0; i < spec_draft.size(); i++) {
spec_i_batch.push_back(batch.n_tokens + i + 1);
}
auto pos0 = prompt.tokens.pos_next();
common_batch_add(batch, sampled, pos0++, { this->id }, true);
for (auto token : spec_draft) {
common_batch_add(batch, token, pos0++, { this->id }, true);
}
}
prompt.tokens.push_back(sampled);
prompt.tokens.insert(spec_draft);
}
void release() {
if (is_processing()) {
GGML_ASSERT(task);
@@ -400,7 +508,7 @@ struct server_slot {
);
}
common_speculative_print_stats(spec);
common_speculative_print_stats(spec.get());
}
json to_json(bool only_metrics = false) const {
@@ -591,16 +699,17 @@ private:
void destroy() {
llama_init.reset();
ctx = nullptr;
model = nullptr;
mtmd_free(mctx);
mctx = nullptr;
// Clear any sampling context
for (server_slot & slot : slots) {
common_speculative_free(slot.spec);
slot.spec = nullptr;
if (slot.can_speculate()) {
slot.spec.reset();
}
}
llama_batch_free(batch);
@@ -642,9 +751,6 @@ private:
llama_init = common_init_from_params(params_base);
// propagate model-metadata sampling defaults back to caller
params.sampling = params_base.sampling;
model = llama_init->model();
ctx = llama_init->context();
@@ -660,6 +766,7 @@ private:
add_bos_token = llama_vocab_get_add_bos(vocab);
if (params_base.speculative.has_dft()) {
// TODO speculative: move to common/speculative.cpp?
SRV_INF("loading draft model '%s'\n", params_base.speculative.mparams_dft.path.c_str());
const auto & params_spec = params_base.speculative;
@@ -727,11 +834,6 @@ private:
params_base.n_cache_reuse = 0;
SRV_WRN("%s\n", "cache_reuse is not supported by multimodal, it will be disabled");
}
if (params_base.speculative.type != COMMON_SPECULATIVE_TYPE_NONE) {
params_base.speculative.type = COMMON_SPECULATIVE_TYPE_NONE;
SRV_WRN("%s\n", "speculative decoding is not supported by multimodal, it will be disabled");
}
}
if (!llama_memory_can_shift(llama_get_memory(ctx))) {
@@ -769,14 +871,23 @@ private:
slots.clear();
const bool can_spec = common_speculative_is_compat(ctx);
if (!can_spec) {
const auto spec_type = common_speculative_is_compat(ctx);
if (spec_type == COMMON_SPECULATIVE_COMPAT_TYPE_NO) {
SRV_WRN("%s", "speculative decoding not supported by this context\n");
}
if (spec_type == COMMON_SPECULATIVE_COMPAT_TYPE_CKPT) {
SRV_WRN("%s", "speculative decoding will use checkpoints\n");
params_base.speculative.use_checkpoints = true;
}
// initialize slots
for (int i = 0; i < params_base.n_parallel; i++) {
server_slot slot;
slots.emplace_back();
}
for (int i = 0; i < params_base.n_parallel; i++) {
server_slot & slot = slots[i];
slot.id = i;
slot.ctx = ctx;
@@ -786,16 +897,11 @@ private:
slot.prompt.tokens.has_mtmd = mctx != nullptr;
// try speculative decoding
if (can_spec) {
slot.spec = common_speculative_init(params_base.speculative, slot.ctx);
if (spec_type != COMMON_SPECULATIVE_COMPAT_TYPE_NO) {
slot.spec.reset(common_speculative_init(params_base.speculative, slot.ctx));
if (slot.spec) {
if (mctx) {
SRV_ERR("%s\n", "speculative decoding is not supported with multimodal");
return false;
}
SLT_INF(slot, "%s", "speculative decoding context initialized\n");
} else {
SLT_INF(slot, "%s", "speculative decoding context not initialized\n");
}
}
@@ -806,8 +912,6 @@ private:
};
slot.reset();
slots.push_back(std::move(slot));
}
{
@@ -854,6 +958,9 @@ private:
model_aliases = params_base.model_alias;
model_tags = params_base.model_tags;
// propagate new defaults back to caller
params = params_base;
if (!is_resume) {
return init();
}
@@ -1197,7 +1304,7 @@ private:
backend_sampling &= task.params.sampling.backend_sampling;
// TODO: speculative decoding requires multiple samples per batch - not supported yet
backend_sampling &= !(slot.spec && task.params.speculative.n_max > 0);
backend_sampling &= !(slot.can_speculate() && task.params.speculative.n_max > 0);
// TODO: getting post/pre sampling logits is not yet supported with backend sampling
backend_sampling &= !need_logits;
@@ -1703,6 +1810,26 @@ private:
return true;
}
// n_tokens_cur: the number of tokens added to the batch for the current slot
void create_checkpoint(server_slot & slot, const int64_t n_tokens_cur, llama_pos pos_min, llama_pos pos_max) {
while (slot.prompt.checkpoints.size() >= (size_t) params_base.n_ctx_checkpoints) {
// make room for the new checkpoint, if needed
const auto & cur = slot.prompt.checkpoints.front();
SLT_WRN(slot, "erasing old context checkpoint (pos_min = %d, pos_max = %d, n_tokens = %" PRId64 ", size = %.3f MiB)\n",
cur.pos_min, cur.pos_max, cur.n_tokens, (float) cur.data.size() / 1024 / 1024);
slot.prompt.checkpoints.erase(slot.prompt.checkpoints.begin());
}
const auto & cur = slot.prompt.checkpoints.emplace_back(server_get_checkpoint(ctx, slot.id, slot.prompt.n_tokens() - n_tokens_cur, pos_min, pos_max));
SLT_WRN(slot,
"created context checkpoint %d of %d (pos_min = %d, pos_max = %d, n_tokens = %" PRId64 ", size = %.3f MiB)\n",
(int) slot.prompt.checkpoints.size(), params_base.n_ctx_checkpoints, cur.pos_min,
cur.pos_max, cur.n_tokens, (float) cur.data.size() / 1024 / 1024);
}
void process_single_task(server_task && task) {
switch (task.type) {
case SERVER_TASK_TYPE_COMPLETION:
@@ -1854,7 +1981,7 @@ private:
std::string filename = task.slot_action.filename;
std::string filepath = task.slot_action.filepath;
const llama_tokens & tokens = slot->prompt.tokens.get_text_tokens();
const llama_tokens & tokens = slot->prompt.tokens.get_tokens();
const size_t nwrite = llama_state_seq_save_file(ctx, filepath.c_str(), slot->id, tokens.data(), token_count);
const int64_t t_end = ggml_time_us();
@@ -2061,7 +2188,7 @@ private:
{
GGML_ASSERT(!slot.prompt.tokens.has_mtmd);
llama_tokens new_tokens = slot.prompt.tokens.get_text_tokens(); // copy
llama_tokens new_tokens = slot.prompt.tokens.get_tokens(); // copy
for (size_t i = n_keep + n_discard; i < new_tokens.size(); i++) {
new_tokens[i - n_discard] = new_tokens[i];
}
@@ -2100,61 +2227,7 @@ private:
continue;
}
// generate draft tokens in speculative decoding mode
// TODO: rework to have a single draft llama_context shared across all slots [TAG_SERVER_SPEC_REWORK]
// perform the speculative drafting for all sequences at the same time in a single batch
const int n_draft_max = slot.get_n_draft_max();
if (n_draft_max > 0) {
if (mctx) {
// we should never reach this, as speculative is automatically disabled if mmproj is loaded
GGML_ABORT("not supported by multimodal");
}
const llama_tokens & cached_text_tokens = slot.prompt.tokens.get_text_tokens();
const auto & params_spec = slot.task->params.speculative;
llama_tokens draft = common_speculative_draft(slot.spec, params_spec, cached_text_tokens, slot.sampled);
if (draft.size() > (size_t) n_draft_max) {
SLT_WRN(slot, "draft size %d exceeds max %d, truncating\n", (int) draft.size(), n_draft_max);
draft.resize(n_draft_max);
}
// add the sampled token to the batch
slot.i_batch_dft.push_back(batch.n_tokens);
common_batch_add(batch, slot.sampled, slot.prompt.tokens.pos_next(), { slot.id }, true);
slot.prompt.tokens.push_back(slot.sampled);
if (slot.task->params.speculative.n_min > (int) draft.size()) {
SLT_DBG(slot, "ignoring small draft: %d < %d\n", (int) draft.size(), slot.task->params.speculative.n_min);
// fallback to normal decoding
slot.i_batch = slot.i_batch_dft[0];
slot.drafted.clear();
slot.i_batch_dft.clear();
} else {
// keep track of total number of drafted tokens tested
slot.n_draft_total += draft.size();
// add all drafted tokens to the batch
for (size_t i = 0; i < draft.size(); i++) {
slot.i_batch_dft.push_back(batch.n_tokens);
common_batch_add(batch, draft[i], slot.prompt.tokens.pos_next(), { slot.id }, true);
slot.prompt.tokens.push_back(draft[i]);
}
slot.drafted = std::move(draft);
}
} else {
// no speculative decoding
slot.i_batch = batch.n_tokens;
common_batch_add(batch, slot.sampled, slot.prompt.tokens.pos_next(), { slot.id }, true);
slot.prompt.tokens.push_back(slot.sampled);
SLT_DBG(slot, "slot decode token, n_ctx = %d, n_tokens = %d, truncated = %d\n",
slot.n_ctx, slot.prompt.n_tokens(), slot.truncated);
}
slot.update_batch(batch);
}
// process in chunks of params.n_batch
@@ -2651,40 +2724,12 @@ private:
// no need to create checkpoints that are too close together
do_checkpoint = do_checkpoint && (slot.prompt.checkpoints.empty() || slot.prompt.n_tokens() - n_tokens_cur > slot.prompt.checkpoints.back().n_tokens + 64);
SLT_DBG(slot, "main/do_checkpoint = %s, pos_min = %d, pos_max = %d\n", do_checkpoint ? "yes" : "no", pos_min, pos_max);
// note: we create the checkpoint before calling llama_decode(), so the current batch is not
// yet processed and therefore it is not part of the checkpoint.
if (do_checkpoint) {
while (slot.prompt.checkpoints.size() >= (size_t) params_base.n_ctx_checkpoints) {
// make room for the new checkpoint, if needed
const auto & cur = slot.prompt.checkpoints.front();
SLT_WRN(slot,
"erasing old context checkpoint (pos_min = %d, pos_max = %d, n_tokens = %" PRId64
", size = %.3f MiB)\n",
cur.pos_min, cur.pos_max, cur.n_tokens, (float) cur.data.size() / 1024 / 1024);
slot.prompt.checkpoints.erase(slot.prompt.checkpoints.begin());
}
const size_t checkpoint_size =
llama_state_seq_get_size_ext(ctx, slot.id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
auto & cur = slot.prompt.checkpoints.emplace_back(server_prompt_checkpoint{
/*.pos_min = */ pos_min,
/*.pos_max = */ pos_max,
/*.n_tokens = */ slot.prompt.n_tokens() - n_tokens_cur,
/*.data = */ std::vector<uint8_t>(checkpoint_size),
});
llama_state_seq_get_data_ext(ctx, cur.data.data(), checkpoint_size, slot.id,
LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
SLT_WRN(slot,
"created context checkpoint %d of %d (pos_min = %d, pos_max = %d, n_tokens = %" PRId64
", size = %.3f MiB)\n",
(int) slot.prompt.checkpoints.size(), params_base.n_ctx_checkpoints, cur.pos_min,
cur.pos_max, cur.n_tokens, (float) cur.data.size() / 1024 / 1024);
create_checkpoint(slot, n_tokens_cur, pos_min, pos_max);
}
}
@@ -2856,19 +2901,19 @@ private:
slot.state = SLOT_STATE_GENERATING;
if (slot.can_speculate()) {
common_speculative_begin(slot.spec, slot.prompt.tokens.get_text_tokens());
common_speculative_begin(slot.spec.get(), slot.prompt.tokens.get_text_tokens());
}
} else if (slot.state != SLOT_STATE_GENERATING) {
continue; // continue loop of slots
}
if (slot.i_batch_dft.size() > 0) {
if (slot.can_speculate() && !slot.spec_draft.empty()) {
continue; // sample using speculative decoding
}
const int tok_idx = slot.i_batch - i;
llama_token id = common_sampler_sample(slot.smpl.get(), ctx, tok_idx);
llama_token id = common_sampler_sample(slot.smpl.get(), slot.ctx, tok_idx);
slot.i_batch = -1;
@@ -2889,7 +2934,7 @@ private:
completion_token_output result;
result.tok = id;
result.text_to_send = common_token_to_piece(ctx, result.tok, accept_special_token(slot, result.tok));
result.text_to_send = common_token_to_piece(slot.ctx, result.tok, accept_special_token(slot, result.tok));
result.prob = 1.0f; // TODO: set it here instead of doing inside populate_token_probs
if (slot.task->params.sampling.n_probs > 0) {
@@ -2909,43 +2954,86 @@ private:
// speculative decoding - main model sample and accept
for (auto & slot : slots) {
if (slot.state != SLOT_STATE_GENERATING || slot.i_batch_dft.empty()) {
if (slot.state != SLOT_STATE_GENERATING || !slot.can_speculate() || slot.spec_draft.empty()) {
continue;
}
const size_t n_draft = slot.drafted.size();
// save the original draft size
const size_t n_draft = slot.spec_draft.size();
// the accepted tokens from the speculation
const auto ids = common_sampler_sample_and_accept_n(slot.smpl.get(), ctx, slot.i_batch_dft, slot.drafted);
slot.i_batch_dft.clear();
slot.drafted.clear();
GGML_ASSERT(n_draft > 0);
// verify and try to accept the draft
{
const auto & params_spec = slot.task->params.speculative;
common_sampler_ptr smpl_save(common_sampler_clone(slot.smpl.get()));
GGML_ASSERT(slot.spec_i_batch.size() == n_draft + 1);
auto accepted = common_sampler_sample_and_accept_n(slot.smpl.get(), slot.ctx, slot.spec_i_batch, slot.spec_draft);
slot.spec_i_batch.clear();
SLT_DBG(slot, "%s: n_draft=%zu, accepted=%zu\n", __func__, slot.spec_draft.size(), accepted.size());
GGML_ASSERT(accepted.size() >= 1);
// check for partial draft acceptance
if (accepted.size() < slot.spec_draft.size() + 1) {
if (params_spec.use_checkpoints) {
// partial acceptance is not supported by the context -> truncate the draft and restore the state
slot.spec_draft = std::move(accepted);
auto & ckpt = slot.spec_ckpt;
SLT_DBG(slot, "restoring speculative checkpoint (pos_min = %d, pos_max = %d, size = %zu)\n", ckpt.pos_min, ckpt.pos_max, ckpt.size());
const size_t n = llama_state_seq_set_data_ext(slot.ctx, ckpt.data.data(), ckpt.size(), slot.id, LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY);
if (n != ckpt.size()) {
GGML_ABORT("%s: failed to restore context checkpoint (pos_min=%d, pos_max=%d, size=%zu, get_data_ext->%zu, set_data_ext->%zu",
__func__, ckpt.pos_min, ckpt.pos_max, ckpt.size(), ckpt.size(), n);
}
llama_memory_seq_rm(llama_get_memory(slot.ctx), slot.id, ckpt.pos_max + 1, -1);
slot.prompt.tokens.keep_first(ckpt.n_tokens);
slot.smpl = std::move(smpl_save);
continue;
}
LOG_DBG("%s: partial acceptance: %zu < %zu\n", __func__, accepted.size(), slot.spec_draft.size());
}
common_speculative_accept(slot.spec.get(), accepted.size() - 1);
slot.spec_draft = std::move(accepted);
}
const int64_t t_current = ggml_time_us();
slot.n_decoded += ids.size();
const auto ids = std::move(slot.spec_draft);
slot.n_decoded += ids.size();
slot.t_token_generation = std::max<int64_t>(1, t_current - slot.t_start_generation) / 1e3;
// update how many tokens out of those tested were accepted
slot.n_draft_accepted += ids.size() - 1;
// inform the speculative decoding about the number of accepted tokens
common_speculative_accept(slot.spec, ids.size() - 1);
// rollback to the state before sampling the draft tokens
slot.prompt.tokens.keep_first(slot.prompt.n_tokens() - n_draft);
slot.n_draft_total += n_draft;
// add accepted tokens to the prompt
slot.prompt.tokens.keep_first(slot.prompt.n_tokens() - n_draft);
slot.prompt.tokens.insert({ids.begin(), ids.end() - 1});
slot.sampled = ids.back(); // last accepted token
llama_memory_seq_rm(llama_get_memory(ctx), slot.id, slot.prompt.n_tokens(), -1);
slot.sampled = ids.back(); // last accepted token
SLT_DBG(slot, "add accepted tokens: sampled=%d, ids.size=%zu, n_draft=%zu\n", slot.sampled, ids.size(), n_draft);
llama_memory_seq_rm(llama_get_memory(slot.ctx), slot.id, slot.prompt.n_tokens(), -1);
for (size_t i = 0; i < ids.size(); ++i) {
completion_token_output result;
result.tok = ids[i];
result.text_to_send = common_token_to_piece(ctx, result.tok, accept_special_token(slot, result.tok));
result.text_to_send = common_token_to_piece(slot.ctx, result.tok, accept_special_token(slot, result.tok));
result.prob = 1.0f; // set later
// TODO: set result.probs
@@ -3665,7 +3753,7 @@ void server_routes::init_routes() {
params.n_predict,
meta->slot_n_ctx,
params.spm_infill,
tokenized_prompts[0].get_text_tokens() // TODO: this could maybe be multimodal.
tokenized_prompts[0].get_tokens() // TODO: this could maybe be multimodal.
);
std::vector<raw_buffer> files; // dummy
tools/server/server-task.cpp
+3 -1
View File
@@ -162,7 +162,7 @@ common_chat_msg task_result_state::update_chat_msg(
bool filter_tool_calls) {
generated_text += text_added;
auto msg_prv_copy = chat_msg;
SRV_DBG("Parsing chat message: %s\n", generated_text.c_str());
//SRV_DBG("Parsing chat message: %s\n", generated_text.c_str());
auto new_msg = common_chat_parse(
generated_text,
is_partial,
@@ -304,6 +304,8 @@ task_params server_task::params_from_json_cmpl(
params.sampling.backend_sampling = json_value(data, "backend_sampling", defaults.sampling.backend_sampling);
params.post_sampling_probs = json_value(data, "post_sampling_probs", defaults.post_sampling_probs);
params.speculative = defaults.speculative;
params.speculative.n_min = json_value(data, "speculative.n_min", defaults.speculative.n_min);
params.speculative.n_max = json_value(data, "speculative.n_max", defaults.speculative.n_max);
params.speculative.p_min = json_value(data, "speculative.p_min", defaults.speculative.p_min);
tools/server/server-task.h
+11
View File
@@ -576,6 +576,17 @@ struct server_prompt_checkpoint {
size_t size() const {
return data.size();
}
bool empty() const {
return data.empty();
}
void clear() {
pos_min = 0;
pos_max = 0;
n_tokens = 0;
data.clear();
}
};
struct server_prompt {