speculative : simplify

ggml-ci
This commit is contained in:
Georgi Gerganov 2024-11-22 11:05:49 +02:00
parent 0f878a657c
commit e4c122b93c
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GPG Key ID: 449E073F9DC10735
3 changed files with 126 additions and 110 deletions

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@ -4,21 +4,31 @@
#include "common.h" #include "common.h"
#include "sampling.h" #include "sampling.h"
#include <cstring>
#define SPEC_VOCAB_MAX_SIZE_DIFFERENCE 128
#define SPEC_VOCAB_CHECK_START_TOKEN_ID 5
struct common_speculative { struct common_speculative {
struct common_speculative_params params; struct common_speculative_params params;
llama_batch batch_dft; llama_batch batch;
struct llama_context * ctx;
struct common_sampler * smpl; struct common_sampler * smpl;
llama_tokens prompt_last; llama_tokens prompt;
}; };
struct common_speculative * common_speculative_init(struct common_speculative_params params) { struct common_speculative * common_speculative_init(
struct common_speculative_params params,
struct llama_context * ctx_dft) {
auto * result = new common_speculative { auto * result = new common_speculative {
/* .params = */ params, /* .params = */ params,
/* .batch_dft = */ llama_batch_init(llama_n_batch(params.ctx_dft), 0, 1), /* .batch = */ llama_batch_init(llama_n_batch(ctx_dft), 0, 1),
/* .smpl = */ nullptr, /* .ctx = */ ctx_dft,
/* .smpl = */ nullptr,
/* .prompt = */ {},
}; };
// TODO: optimize or pass from outside? // TODO: optimize or pass from outside?
@ -36,7 +46,7 @@ struct common_speculative * common_speculative_init(struct common_speculative_pa
COMMON_SAMPLER_TYPE_INFILL, COMMON_SAMPLER_TYPE_INFILL,
}; };
result->smpl = common_sampler_init(params.model_dft, sparams); result->smpl = common_sampler_init(llama_get_model(ctx_dft), sparams);
} }
#else #else
{ {
@ -49,46 +59,104 @@ struct common_speculative * common_speculative_init(struct common_speculative_pa
COMMON_SAMPLER_TYPE_TOP_K, COMMON_SAMPLER_TYPE_TOP_K,
}; };
result->smpl = common_sampler_init(params.model_dft, sparams); result->smpl = common_sampler_init(llama_get_model(ctx_dft), sparams);
} }
#endif #endif
result->batch_dft = llama_batch_init(llama_n_batch(params.ctx_dft), 0, 1);
return result; return result;
} }
void common_speculative_free(struct common_speculative * spec) { void common_speculative_free(struct common_speculative * spec) {
common_sampler_free(spec->smpl); common_sampler_free(spec->smpl);
llama_batch_free(spec->batch_dft); llama_batch_free(spec->batch);
delete spec; delete spec;
} }
bool common_speculative_are_compatible(
const struct llama_context * ctx_tgt,
const struct llama_context * ctx_dft) {
const struct llama_model * model_tgt = llama_get_model(ctx_tgt);
const struct llama_model * model_dft = llama_get_model(ctx_dft);
const bool vocab_type_tgt = llama_vocab_type(model_tgt);
LOG_DBG("%s: vocab_type tgt: %d\n", __func__, vocab_type_tgt);
const bool vocab_type_dft = llama_vocab_type(model_dft);
LOG_DBG("%s: vocab_type dft: %d\n", __func__, vocab_type_dft);
if (vocab_type_tgt != vocab_type_dft) {
LOG_ERR("%s: draft model vocab type must match target model to use speculation but "
"vocab_type_dft = %d while vocab_type_tgt = %d\n", __func__, vocab_type_dft, vocab_type_tgt);
return false;
}
if (llama_add_bos_token(model_tgt) != llama_add_bos_token(model_dft) ||
llama_add_eos_token(model_tgt) != llama_add_eos_token(model_dft) ||
llama_token_bos(model_tgt) != llama_token_bos(model_dft) ||
llama_token_eos(model_tgt) != llama_token_eos(model_dft)
) {
LOG_ERR("%s: draft model special tokens must match target model to use speculation\n", __func__);
return false;
}
{
const int n_vocab_tgt = llama_n_vocab(model_tgt);
const int n_vocab_dft = llama_n_vocab(model_dft);
const int vocab_diff = std::abs(n_vocab_tgt - n_vocab_dft);
if (vocab_diff > SPEC_VOCAB_MAX_SIZE_DIFFERENCE) {
LOG_ERR("%s: draft model vocab must closely match target model to use speculation but "
"target vocab size %d does not match draft vocab size %d - difference %d, max allowed %d\n",
__func__, n_vocab_tgt, llama_n_vocab(model_dft), vocab_diff, SPEC_VOCAB_MAX_SIZE_DIFFERENCE);
return false;
}
for (int i = SPEC_VOCAB_CHECK_START_TOKEN_ID; i < std::min(n_vocab_tgt, n_vocab_dft); ++i) {
const char * token_text_tgt = llama_token_get_text(model_tgt, i);
const char * token_text_dft = llama_token_get_text(model_dft, i);
if (std::strcmp(token_text_tgt, token_text_dft) != 0) {
LOG_ERR("%s: draft model vocab must match target model to use speculation but "
"token %d content differs - target '%s', draft '%s'\n", __func__, i,
common_token_to_piece(ctx_tgt, i).c_str(),
common_token_to_piece(ctx_dft, i).c_str());
return false;
}
}
}
return true;
}
void common_speculative_add_draft( void common_speculative_add_draft(
struct common_speculative * spec, struct common_speculative * spec,
struct llama_batch & batch_tgt, struct llama_batch & batch_tgt,
const llama_tokens & prompt, const llama_tokens & prompt_tgt,
llama_token id_last, llama_token id_last,
llama_token n_past_tgt) { llama_token n_past_tgt) {
auto & batch = spec->batch;
auto & ctx = spec->ctx;
auto & smpl = spec->smpl;
auto & prompt = spec->prompt;
int reuse_i = 0; int reuse_i = 0;
int reuse_n = 0; int reuse_n = 0;
const int n_ctx = llama_n_ctx(spec->params.ctx_dft) - spec->params.n_draft; const int n_ctx = llama_n_ctx(ctx) - spec->params.n_draft;
const int i_start = std::max<int>(0, (int) prompt.size() - n_ctx); const int i_start = std::max<int>(0, (int) prompt_tgt.size() - n_ctx);
for (int i = 0; i < (int) spec->prompt_last.size(); ++i) { for (int i = 0; i < (int) prompt.size(); ++i) {
int cur = 0; int cur = 0;
while (i_start + cur < (int) prompt.size() && while (i_start + cur < (int) prompt_tgt.size() &&
i + cur < (int) spec->prompt_last.size() && i + cur < (int) prompt.size() &&
prompt[i_start + cur] == spec->prompt_last[i + cur]) { prompt_tgt[i_start + cur] == prompt[i + cur]) {
cur++; cur++;
} }
if ((cur >= spec->params.n_reuse || prompt.size() <= n_ctx) && cur > reuse_n) { if ((cur >= spec->params.n_reuse || prompt_tgt.size() <= n_ctx) && cur > reuse_n) {
reuse_i = i; reuse_i = i;
reuse_n = cur; reuse_n = cur;
} }
@ -97,59 +165,59 @@ void common_speculative_add_draft(
LOG_DBG("%s: reuse_i = %d, reuse_n = %d\n", __func__, reuse_i, reuse_n); LOG_DBG("%s: reuse_i = %d, reuse_n = %d\n", __func__, reuse_i, reuse_n);
if (reuse_n == 0) { if (reuse_n == 0) {
llama_kv_cache_clear(spec->params.ctx_dft); llama_kv_cache_clear(ctx);
spec->prompt_last.clear(); prompt.clear();
} else { } else {
llama_kv_cache_seq_rm (spec->params.ctx_dft, 0, 0, reuse_i); llama_kv_cache_seq_rm (ctx, 0, 0, reuse_i);
llama_kv_cache_seq_rm (spec->params.ctx_dft, 0, reuse_i + reuse_n, -1); llama_kv_cache_seq_rm (ctx, 0, reuse_i + reuse_n, -1);
llama_kv_cache_seq_add(spec->params.ctx_dft, 0, reuse_i, -1, -reuse_i); llama_kv_cache_seq_add(ctx, 0, reuse_i, -1, -reuse_i);
spec->prompt_last.erase(spec->prompt_last.begin(), spec->prompt_last.begin() + reuse_i); prompt.erase(prompt.begin(), prompt.begin() + reuse_i);
spec->prompt_last.erase(spec->prompt_last.begin() + reuse_n, spec->prompt_last.end()); prompt.erase(prompt.begin() + reuse_n, prompt.end());
} }
common_batch_clear(spec->batch_dft); common_batch_clear(batch);
for (int i = i_start + reuse_n; i < (int) prompt.size(); ++i) { for (int i = i_start + reuse_n; i < (int) prompt_tgt.size(); ++i) {
//LOG_DBG("i = %d, i_start = %d, reuse_n = %d, i - i_start = %d, id = %6d\n", i, i_start, reuse_n, i - i_start, prompt[i]); //LOG_DBG("i = %d, i_start = %d, reuse_n = %d, i - i_start = %d, id = %6d\n", i, i_start, reuse_n, i - i_start, prompt_tgt[i]);
common_batch_add(spec->batch_dft, prompt[i], i - i_start, { 0 }, false); common_batch_add(batch, prompt_tgt[i], i - i_start, { 0 }, false);
spec->prompt_last.push_back(prompt[i]); prompt.push_back(prompt_tgt[i]);
} }
const llama_pos n_past = prompt.size() - i_start; const llama_pos n_past = prompt_tgt.size() - i_start;
LOG_DBG("%s: n_past = %d\n", __func__, n_past); LOG_DBG("%s: n_past = %d\n", __func__, n_past);
if (spec->batch_dft.n_tokens > 0) { if (batch.n_tokens > 0) {
LOG_DBG("%s: draft batch: %s\n", __func__, string_from(spec->params.ctx_dft, spec->batch_dft).c_str()); LOG_DBG("%s: draft batch: %s\n", __func__, string_from(ctx, batch).c_str());
llama_decode(spec->params.ctx_dft, spec->batch_dft); llama_decode(ctx, batch);
} }
common_batch_clear(spec->batch_dft); common_batch_clear(batch);
common_batch_add (spec->batch_dft, id_last, n_past, { 0 }, true); common_batch_add (batch, id_last, n_past, { 0 }, true);
spec->prompt_last.push_back(id_last); prompt.push_back(id_last);
LOG_DBG("%s: prompt_last: %s\n", __func__, string_from(spec->params.ctx_dft, spec->prompt_last).c_str()); LOG_DBG("%s: prompt_last: %s\n", __func__, string_from(ctx, prompt).c_str());
llama_decode(spec->params.ctx_dft, spec->batch_dft); llama_decode(ctx, batch);
common_sampler_reset(spec->smpl); common_sampler_reset(smpl);
// sample n_draft tokens from the draft model // sample n_draft tokens from the draft model
for (int i = 0; i < spec->params.n_draft; ++i) { for (int i = 0; i < spec->params.n_draft; ++i) {
common_batch_clear(spec->batch_dft); common_batch_clear(batch);
common_sampler_sample(spec->smpl, spec->params.ctx_dft, 0, true); common_sampler_sample(smpl, ctx, 0, true);
const auto * cur_p = common_sampler_get_candidates(spec->smpl); const auto * cur_p = common_sampler_get_candidates(smpl);
for (int k = 0; k < std::min(3, (int) cur_p->size); ++k) { for (int k = 0; k < std::min(3, (int) cur_p->size); ++k) {
LOG_DBG(" - draft candidate %3d, pos %3d: %6d (%8.3f) '%s'\n", LOG_DBG(" - draft candidate %3d, pos %3d: %6d (%8.3f) '%s'\n",
k, i, cur_p->data[k].id, cur_p->data[k].p, common_token_to_piece(spec->params.ctx_dft, cur_p->data[k].id).c_str()); k, i, cur_p->data[k].id, cur_p->data[k].p, common_token_to_piece(ctx, cur_p->data[k].id).c_str());
} }
// add drafted token for each sequence // add drafted token for each sequence
@ -160,7 +228,7 @@ void common_speculative_add_draft(
break; break;
} }
common_sampler_accept(spec->smpl, id, true); common_sampler_accept(smpl, id, true);
common_batch_add(batch_tgt, id, n_past_tgt + i, { 0 }, true); common_batch_add(batch_tgt, id, n_past_tgt + i, { 0 }, true);
@ -168,12 +236,12 @@ void common_speculative_add_draft(
break; break;
} }
common_batch_add(spec->batch_dft, id, n_past + i + 1, { 0 }, true); common_batch_add(batch, id, n_past + i + 1, { 0 }, true);
// evaluate the drafted tokens on the draft model // evaluate the drafted tokens on the draft model
llama_decode(spec->params.ctx_dft, spec->batch_dft); llama_decode(ctx, batch);
spec->prompt_last.push_back(id); prompt.push_back(id);
} }
// don't waste time on small batches // don't waste time on small batches

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@ -11,16 +11,18 @@ struct common_speculative_params {
int n_reuse = 256; int n_reuse = 256;
float p_min = 0.9f; float p_min = 0.9f;
struct llama_model * model_dft = nullptr;
struct llama_context * ctx_dft = nullptr;
}; };
struct common_speculative * common_speculative_init(struct common_speculative_params params); struct common_speculative * common_speculative_init(
struct common_speculative_params params,
struct llama_context * ctx_dft);
void common_speculative_free(struct common_speculative * spec); void common_speculative_free(struct common_speculative * spec);
bool common_speculative_are_compatible(
const struct llama_context * ctx_tgt,
const struct llama_context * ctx_dft);
// sample up to n_draft tokens and add them to the batch using the draft model // sample up to n_draft tokens and add them to the batch using the draft model
// //
void common_speculative_add_draft( void common_speculative_add_draft(

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@ -5,21 +5,14 @@
#include "log.h" #include "log.h"
#include "llama.h" #include "llama.h"
#include <algorithm>
#include <cstdio> #include <cstdio>
#include <cstring> #include <cstring>
#include <string> #include <string>
#include <vector> #include <vector>
#define SPEC_VOCAB_MAX_SIZE_DIFFERENCE 128
#define SPEC_VOCAB_CHECK_START_TOKEN_ID 5
int main(int argc, char ** argv) { int main(int argc, char ** argv) {
common_params params; common_params params;
// needed to get candidate probs even for temp <= 0.0
params.sparams.n_probs = 128;
if (!common_params_parse(argc, argv, params, LLAMA_EXAMPLE_SPECULATIVE)) { if (!common_params_parse(argc, argv, params, LLAMA_EXAMPLE_SPECULATIVE)) {
return 1; return 1;
} }
@ -63,55 +56,10 @@ int main(int argc, char ** argv) {
model_dft = llama_init_dft.model; model_dft = llama_init_dft.model;
ctx_dft = llama_init_dft.context; ctx_dft = llama_init_dft.context;
const bool vocab_type_tgt = llama_vocab_type(model_tgt); if (!common_speculative_are_compatible(ctx_tgt, ctx_dft)) {
LOG_DBG("vocab_type tgt: %d\n", vocab_type_tgt);
const bool vocab_type_dft = llama_vocab_type(model_dft);
LOG_DBG("vocab_type dft: %d\n", vocab_type_dft);
if (vocab_type_tgt != vocab_type_dft) {
LOG_ERR("%s: draft model vocab type must match target model to use speculation but ", __func__);
LOG_ERR("vocab_type_dft = %d while vocab_type_tgt = %d\n", vocab_type_dft, vocab_type_tgt);
return 1; return 1;
} }
if (
llama_add_bos_token(model_tgt) != llama_add_bos_token(model_dft) ||
llama_add_eos_token(model_tgt) != llama_add_eos_token(model_dft) ||
llama_token_bos(model_tgt) != llama_token_bos(model_dft) ||
llama_token_eos(model_tgt) != llama_token_eos(model_dft)
) {
LOG_ERR("%s: draft model special tokens must match target model to use speculation\n", __func__);
return 1;
}
{
const int n_vocab_tgt = llama_n_vocab(model_tgt);
const int n_vocab_dft = llama_n_vocab(model_dft);
const int vocab_diff = n_vocab_tgt > n_vocab_dft
? n_vocab_tgt - n_vocab_dft
: n_vocab_dft - n_vocab_tgt;
if (vocab_diff > SPEC_VOCAB_MAX_SIZE_DIFFERENCE) {
LOG_ERR("%s: draft model vocab must closely match target model to use speculation but ", __func__);
LOG_ERR("target vocab size %d does not match draft vocab size %d - difference %d, max allowed %d\n",
n_vocab_tgt, llama_n_vocab(model_dft), vocab_diff, SPEC_VOCAB_MAX_SIZE_DIFFERENCE);
return 1;
}
for (int i = SPEC_VOCAB_CHECK_START_TOKEN_ID; i < std::min(n_vocab_tgt, n_vocab_dft); ++i) {
const char * token_text_tgt = llama_token_get_text(model_tgt, i);
const char * token_text_dft = llama_token_get_text(model_dft, i);
if (std::strcmp(token_text_tgt, token_text_dft) != 0) {
LOG_ERR("%s: draft model vocab must match target model to use speculation but ", __func__);
LOG_ERR("token %d content differs - target '%s', draft '%s'\n", i,
common_token_to_piece(ctx_tgt, i).c_str(),
common_token_to_piece(ctx_dft, i).c_str());
return 1;
}
}
}
// Tokenize the prompt // Tokenize the prompt
std::vector<llama_token> inp; std::vector<llama_token> inp;
inp = common_tokenize(ctx_tgt, params.prompt, true, true); inp = common_tokenize(ctx_tgt, params.prompt, true, true);
@ -167,10 +115,8 @@ int main(int argc, char ** argv) {
params_spec.n_min = 5; params_spec.n_min = 5;
params_spec.n_reuse = 256; params_spec.n_reuse = 256;
params_spec.p_min = 0.9f; params_spec.p_min = 0.9f;
params_spec.model_dft = model_dft;
params_spec.ctx_dft = ctx_dft;
struct common_speculative * spec = common_speculative_init(params_spec); struct common_speculative * spec = common_speculative_init(params_spec, ctx_dft);
llama_batch batch_tgt = llama_batch_init(llama_n_batch(ctx_tgt), 0, 1); llama_batch batch_tgt = llama_batch_init(llama_n_batch(ctx_tgt), 0, 1);