haraldwolff/llama.cpp
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llama : minimize size used for state save/load (#4820)

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* examples : save-load-state: save only required state

* llama : only reserve n_vocab * n_batch at most for logits

llama_decode asserts that only n_batch tokens are passed each call, and
n_ctx is expected to be bigger than n_batch.

* llama : always reserve n_vocab * n_batch for logits

llama_context de-serialization breaks if the contexts have differing
capacity for logits and llama_decode will at maximum resize to
n_vocab * n_batch.

* llama : only save and restore used logits

for batch sizes of 512 this reduces save state in the best case by
around 62 MB, which can be a lot if planning to save on each message
to allow regenerating messages.

* llama : use ostringstream and istringstream for save and load

* llama : serialize rng into minimum amount of space required

* llama : break session version due to serialization changes
This commit is contained in:
David Friehs 2024-01-13 17:29:43 +01:00 committed by GitHub
parent 6b48ed0893
commit df845cc982
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3 changed files with 29 additions and 47 deletions
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21
examples/save-load-state/save-load-state.cpp
View file

@ -45,13 +45,13 @@ int main(int argc, char ** argv) {
// save state (rng, logits, embedding and kv_cache) to file
{
std::vector<uint8_t> state_mem(llama_get_state_size(ctx));
const size_t written = llama_copy_state_data(ctx, state_mem.data());
{
FILE *fp_write = fopen("dump_state.bin", "wb");
llama_copy_state_data(ctx, state_mem.data()); // could also copy directly to memory mapped file
fwrite(state_mem.data(), 1, state_mem.size(), fp_write);
fclose(fp_write);
}
FILE *fp_write = fopen("dump_state.bin", "wb");
fwrite(state_mem.data(), 1, written, fp_write);
fclose(fp_write);
fprintf(stderr, "%s : serialized state into %zd out of a maximum of %zd bytes\n", __func__, written, state_mem.size());
}
// save state (last tokens)
@ -100,18 +100,17 @@ int main(int argc, char ** argv) {
std::vector<uint8_t> state_mem(llama_get_state_size(ctx2));
FILE * fp_read = fopen("dump_state.bin", "rb");
const size_t read = fread(state_mem.data(), 1, state_mem.size(), fp_read);
fclose(fp_read);
const size_t ret = fread(state_mem.data(), 1, state_mem.size(), fp_read);
if (ret != state_mem.size()) {
if (read != llama_set_state_data(ctx2, state_mem.data())) {
fprintf(stderr, "\n%s : failed to read state\n", __func__);
llama_free(ctx2);
llama_free_model(model);
return 1;
}
llama_set_state_data(ctx2, state_mem.data());
fclose(fp_read);
fprintf(stderr, "%s : deserialized state from %zd out of a maximum of %zd bytes\n", __func__, read, state_mem.size());
}
// restore state (last tokens)

53
llama.cpp
View file

@ -9379,12 +9379,8 @@ struct llama_context * llama_new_context_with_model(
ggml_type_name(type_v), (float)memory_size_v / (1024.0f * 1024.0f));
}
// resized during inference
if (params.logits_all) {
ctx->logits.reserve(cparams.n_ctx*hparams.n_vocab);
} else {
ctx->logits.reserve(hparams.n_vocab);
}
// resized during inference, reserve maximum
ctx->logits.reserve(hparams.n_vocab*cparams.n_batch);
if (params.embedding){
ctx->embedding.resize(hparams.n_embd);
@ -9731,8 +9727,8 @@ size_t llama_get_state_size(const struct llama_context * ctx) {
// for reference, std::mt19937(1337) serializes to 6701 bytes.
const size_t s_rng_size = sizeof(size_t);
const size_t s_rng = LLAMA_MAX_RNG_STATE;
const size_t s_logits_capacity = sizeof(size_t);
const size_t s_logits_size = sizeof(size_t);
// assume worst case for logits although only currently set ones are serialized
const size_t s_logits = ctx->logits.capacity() * sizeof(float);
const size_t s_embedding_size = sizeof(size_t);
const size_t s_embedding = ctx->embedding.size() * sizeof(float);
@ -9743,7 +9739,6 @@ size_t llama_get_state_size(const struct llama_context * ctx) {
const size_t s_total = (
+ s_rng_size
+ s_rng
+ s_logits_capacity
+ s_logits_size
+ s_logits
+ s_embedding_size
@ -9812,37 +9807,27 @@ struct llama_data_file_context : llama_data_context {
static void llama_copy_state_data_internal(struct llama_context * ctx, llama_data_context * data_ctx) {
// copy rng
{
std::stringstream rng_ss;
std::ostringstream rng_ss;
rng_ss << ctx->rng;
const size_t rng_size = rng_ss.str().size();
char rng_buf[LLAMA_MAX_RNG_STATE];
const std::string & rng_str = rng_ss.str();
const size_t rng_size = rng_str.size();
memset(&rng_buf[0], 0, LLAMA_MAX_RNG_STATE);
memcpy(&rng_buf[0], rng_ss.str().data(), rng_ss.str().size());
GGML_ASSERT(rng_size <= LLAMA_MAX_RNG_STATE);
data_ctx->write(&rng_size, sizeof(rng_size));
data_ctx->write(&rng_buf[0], LLAMA_MAX_RNG_STATE);
data_ctx->write(&rng_size, sizeof(rng_size));
data_ctx->write(rng_str.data(), rng_size);
}
// copy logits
{
const size_t logits_cap = ctx->logits.capacity();
const size_t logits_size = ctx->logits.size();
data_ctx->write(&logits_cap, sizeof(logits_cap));
data_ctx->write(&logits_size, sizeof(logits_size));
if (logits_size) {
data_ctx->write(ctx->logits.data(), logits_size * sizeof(float));
}
// If there is a gap between the size and the capacity, write padding
size_t padding_size = (logits_cap - logits_size) * sizeof(float);
if (padding_size > 0) {
std::vector<uint8_t> padding(padding_size, 0); // Create a buffer filled with zeros
data_ctx->write(padding.data(), padding_size);
}
}
// copy embeddings
@ -9925,13 +9910,13 @@ size_t llama_set_state_data(struct llama_context * ctx, uint8_t * src) {
// set rng
{
size_t rng_size;
char rng_buf[LLAMA_MAX_RNG_STATE];
memcpy(&rng_size, inp, sizeof(rng_size)); inp += sizeof(rng_size);
memcpy(&rng_size, inp, sizeof(rng_size)); inp += sizeof(rng_size);
memcpy(&rng_buf[0], inp, LLAMA_MAX_RNG_STATE); inp += LLAMA_MAX_RNG_STATE;
GGML_ASSERT(rng_size <= LLAMA_MAX_RNG_STATE);
std::stringstream rng_ss;
rng_ss.str(std::string(&rng_buf[0], rng_size));
std::string rng_str((char *)inp, rng_size); inp += rng_size;
std::istringstream rng_ss(rng_str);
rng_ss >> ctx->rng;
GGML_ASSERT(!rng_ss.fail());
@ -9939,20 +9924,18 @@ size_t llama_set_state_data(struct llama_context * ctx, uint8_t * src) {
// set logits
{
size_t logits_cap;
size_t logits_size;
memcpy(&logits_cap, inp, sizeof(logits_cap)); inp += sizeof(logits_cap);
memcpy(&logits_size, inp, sizeof(logits_size)); inp += sizeof(logits_size);
GGML_ASSERT(ctx->logits.capacity() == logits_cap);
GGML_ASSERT(ctx->logits.capacity() >= logits_size);
if (logits_size) {
ctx->logits.resize(logits_size);
memcpy(ctx->logits.data(), inp, logits_size * sizeof(float));
}
inp += logits_cap * sizeof(float);
memcpy(ctx->logits.data(), inp, logits_size * sizeof(float));
inp += logits_size * sizeof(float);
}
}
// set embeddings

2
llama.h
View file

@ -43,7 +43,7 @@
#define LLAMA_FILE_MAGIC_GGSN 0x6767736eu // 'ggsn'
#define LLAMA_SESSION_MAGIC LLAMA_FILE_MAGIC_GGSN
#define LLAMA_SESSION_VERSION 3
#define LLAMA_SESSION_VERSION 4
#if defined(GGML_USE_CUBLAS) || defined(GGML_USE_CLBLAST) || defined(GGML_USE_METAL)
// Defined when llama.cpp is compiled with support for offloading model layers to GPU.