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llama : adapter
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ggml-ci
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ggerganov committed Dec 22, 2024
1 parent cdeebe5 commit dcbfda1
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Showing 7 changed files with 383 additions and 329 deletions.
10 changes: 10 additions & 0 deletions common/common.h
Original file line number Diff line number Diff line change
Expand Up @@ -481,7 +481,17 @@ std::string fs_get_cache_file(const std::string & filename);
struct common_init_result {
struct llama_model * model = nullptr;
struct llama_context * context = nullptr;

std::vector<common_lora_adapter_container> lora_adapters;

~common_init_result() {
llama_free(context);
llama_free_model(model);

for (auto & lora_adapter : lora_adapters) {
llama_lora_adapter_free(lora_adapter.adapter);
}
}
};

struct common_init_result common_init_from_params(common_params & params);
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5 changes: 2 additions & 3 deletions include/llama.h
Original file line number Diff line number Diff line change
Expand Up @@ -417,6 +417,7 @@ extern "C" {
const char * path_model,
struct llama_model_params params);

// TODO: rename to llama_model_free
LLAMA_API void llama_free_model(struct llama_model * model);

// TODO: rename to llama_init_from_model
Expand Down Expand Up @@ -507,7 +508,6 @@ extern "C" {
//

// Load a LoRA adapter from file
// The loaded adapter will be associated to the given model, and will be free when the model is deleted
// TODO: rename to llama_adapter_lora_init
LLAMA_API struct llama_lora_adapter * llama_lora_adapter_init(
struct llama_model * model,
Expand All @@ -530,8 +530,7 @@ extern "C" {

// Remove all LoRA adapters from given context
// TODO: rename to llama_clear_adapter_lora
LLAMA_API void llama_lora_adapter_clear(
struct llama_context * ctx);
LLAMA_API void llama_lora_adapter_clear(struct llama_context * ctx);

// Manually free a LoRA adapter
// Note: loaded adapters will be free when the associated model is deleted
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313 changes: 313 additions & 0 deletions src/llama-adapter.cpp
Original file line number Diff line number Diff line change
@@ -1,5 +1,318 @@
#include "llama-adapter.h"

#include "llama-model.h"

#include <algorithm>
#include <map>
#include <cassert>

// vec

struct ggml_tensor * llama_control_vector::tensor_for(int il) const {
if (il < 0 || il < layer_start || il > layer_end || (size_t) il >= tensors.size()) {
return nullptr;
}

return tensors[il];
}

struct ggml_tensor * llama_control_vector::apply_to(struct ggml_context * ctx, struct ggml_tensor * cur, int il) const {
ggml_tensor * layer_dir = tensor_for(il);
if (layer_dir != nullptr) {
cur = ggml_add(ctx, cur, layer_dir);
}

return cur;
}

static bool llama_control_vector_init(struct llama_control_vector & cvec, const llama_model & model) {
const auto & hparams = model.hparams;

GGML_ASSERT(cvec.tensors.empty());
GGML_ASSERT(cvec.ctxs.empty());
GGML_ASSERT(cvec.bufs.empty());

// create a context for each buffer type
std::map<ggml_backend_buffer_type_t, ggml_context *> ctx_map;
auto ctx_for_buft = [&](ggml_backend_buffer_type_t buft) -> ggml_context * {
auto it = ctx_map.find(buft);
if (it == ctx_map.end()) {
struct ggml_init_params params = {
/*.mem_size =*/ hparams.n_layer*ggml_tensor_overhead(),
/*.mem_buffer =*/ NULL,
/*.no_alloc =*/ true,
};

ggml_context * ctx = ggml_init(params);
if (!ctx) {
return nullptr;
}

ctx_map[buft] = ctx;
cvec.ctxs.emplace_back(ctx);

return ctx;
}

return it->second;
};

// make tensors
cvec.tensors.reserve(hparams.n_layer);
cvec.tensors.push_back(nullptr); // there's never a tensor for layer 0
for (size_t il = 1; il < hparams.n_layer; il++) {
ggml_backend_buffer_type_t buft = llama_model_select_buft(model, il);
ggml_context * ctx = ctx_for_buft(buft);
if (!ctx) {
LLAMA_LOG_ERROR("%s: failed to allocate context for control vector\n", __func__);
return false;
}
ggml_tensor * tensor = ggml_new_tensor_1d(ctx, GGML_TYPE_F32, hparams.n_embd);
cvec.tensors.push_back(tensor);
}

// allocate tensors / buffers and zero
cvec.bufs.reserve(ctx_map.size());
for (auto it : ctx_map) {
ggml_backend_buffer_type_t buft = it.first;
ggml_context * ctx = it.second;
ggml_backend_buffer_t buf = ggml_backend_alloc_ctx_tensors_from_buft(ctx, buft);
if (!buf) {
LLAMA_LOG_ERROR("%s: failed to allocate buffer for control vector\n", __func__);
return false;
}
ggml_backend_buffer_clear(buf, 0);
cvec.bufs.emplace_back(buf);
}

return true;
}

int32_t llama_control_vector_apply(
struct llama_control_vector & cvec,
const llama_model & model,
const float * data,
size_t len,
int32_t n_embd,
int32_t il_start,
int32_t il_end) {
const auto & hparams = model.hparams;

if (data == nullptr) {
// disable the current control vector (but leave allocated for later)
cvec.layer_start = -1;
cvec.layer_end = -1;
return 0;
}

if (n_embd != (int) hparams.n_embd) {
LLAMA_LOG_ERROR("%s: control vector n_embd does not match model\n", __func__);
return 1;
}

if (cvec.tensors.empty()) {
if (!llama_control_vector_init(cvec, model)) {
return 1;
}
}

cvec.layer_start = il_start;
cvec.layer_end = il_end;

for (size_t il = 1; il < hparams.n_layer; il++) {
assert(cvec.tensors[il] != nullptr);

const size_t off = n_embd * (il - 1); // buffer doesn't have data for layer 0, since it's never present
if (off + n_embd <= len) {
ggml_backend_tensor_set(cvec.tensors[il], data + off, 0, n_embd * ggml_element_size(cvec.tensors[il]));
}
}

return 0;
}

// lora

llama_lora_weight * llama_lora_adapter::get_weight(struct ggml_tensor * w) {
const std::string name(w->name);

const auto pos = ab_map.find(name);
if (pos != ab_map.end()) {
return &pos->second;
}

return nullptr;
}

void llama_lora_adapter_free(struct llama_lora_adapter * adapter) {
delete adapter;
}

void llama_lora_adapter_init_impl(struct llama_model & model, const char * path_lora, struct llama_lora_adapter & adapter) {
LLAMA_LOG_INFO("%s: loading lora adapter from '%s' ...\n", __func__, path_lora);

ggml_context * ctx_init;
struct gguf_init_params meta_gguf_params = {
/* .no_alloc = */ true,
/* .ctx = */ &ctx_init,
};

gguf_context_ptr ctx_gguf { gguf_init_from_file(path_lora, meta_gguf_params) };
if (!ctx_gguf) {
throw std::runtime_error("failed to load lora adapter file from " + std::string(path_lora));
}

ggml_context_ptr ctx { ctx_init };

// check metadata
{
auto get_kv_str = [&](const std::string & key) -> std::string {
int id = gguf_find_key(ctx_gguf.get(), key.c_str());
return id < 0 ? "" : std::string(gguf_get_val_str(ctx_gguf.get(), id));
};
auto get_kv_f32 = [&](const std::string & key) -> float {
int id = gguf_find_key(ctx_gguf.get(), key.c_str());
return id < 0 ? 0.0f : gguf_get_val_f32(ctx_gguf.get(), id);
};
LLM_KV llm_kv = LLM_KV(LLM_ARCH_UNKNOWN);

auto general_type = get_kv_str(llm_kv(LLM_KV_GENERAL_TYPE));
if (general_type != "adapter") {
throw std::runtime_error("expect general.type to be 'adapter', but got: " + general_type);
}

auto general_arch_str = get_kv_str(llm_kv(LLM_KV_GENERAL_ARCHITECTURE));
auto general_arch = llm_arch_from_string(general_arch_str);
if (general_arch != model.arch) {
throw std::runtime_error("model arch and LoRA arch mismatch");
}

auto adapter_type = get_kv_str(llm_kv(LLM_KV_ADAPTER_TYPE));
if (adapter_type != "lora") {
throw std::runtime_error("expect adapter.type to be 'lora', but got: " + adapter_type);
}

adapter.alpha = get_kv_f32(llm_kv(LLM_KV_ADAPTER_LORA_ALPHA));
}

int n_tensors = gguf_get_n_tensors(ctx_gguf.get());

// contexts for each buffer type
std::map<ggml_backend_buffer_type_t, ggml_context *> ctx_map;
auto ctx_for_buft = [&](ggml_backend_buffer_type_t buft) -> ggml_context * {
auto it = ctx_map.find(buft);
if (it == ctx_map.end()) {
// add a new context
struct ggml_init_params params = {
/*.mem_size =*/ n_tensors*ggml_tensor_overhead(),
/*.mem_buffer =*/ NULL,
/*.no_alloc =*/ true,
};
ggml_context * buft_ctx = ggml_init(params);
if (!buft_ctx) {
return nullptr;
}
ctx_map[buft] = buft_ctx;
adapter.ctxs.emplace_back(buft_ctx);
return buft_ctx;
};
return it->second;
};

// bundle lora_a and lora_b into pairs
std::map<std::string, llama_lora_weight> ab_map;
auto str_endswith = [](const std::string & str, const std::string & suffix) {
return str.size() >= suffix.size() && str.compare(str.size()-suffix.size(), suffix.size(), suffix) == 0;
};

for (ggml_tensor * cur = ggml_get_first_tensor(ctx.get()); cur; cur = ggml_get_next_tensor(ctx.get(), cur)) {
std::string name(cur->name);
if (str_endswith(name, ".lora_a")) {
replace_all(name, ".lora_a", "");
if (ab_map.find(name) == ab_map.end()) {
ab_map[name] = llama_lora_weight(cur, nullptr);
} else {
ab_map[name].a = cur;
}
} else if (str_endswith(name, ".lora_b")) {
replace_all(name, ".lora_b", "");
if (ab_map.find(name) == ab_map.end()) {
ab_map[name] = llama_lora_weight(nullptr, cur);
} else {
ab_map[name].b = cur;
}
} else {
throw std::runtime_error("LoRA tensor '" + name + "' has unexpected suffix");
}
}

// add tensors
for (auto & it : ab_map) {
const std::string & name = it.first;
llama_lora_weight & w = it.second;

if (!w.a || !w.b) {
throw std::runtime_error("LoRA tensor pair for '" + name + "' is missing one component");
}

// device buft and device ctx
auto * model_tensor = llama_model_get_tensor(model, name.c_str());
if (!model_tensor) {
throw std::runtime_error("LoRA tensor '" + name + "' does not exist in base model");
}

struct ggml_context * dev_ctx = ctx_for_buft(ggml_backend_buffer_get_type(model_tensor->buffer));
// validate tensor shape
if (model_tensor->ne[0] != w.a->ne[0] || model_tensor->ne[1] != w.b->ne[1]) {
throw std::runtime_error("tensor '" + name + "' has incorrect shape");
}
if (w.a->ne[1] != w.b->ne[0]) {
throw std::runtime_error("lora_a tensor is not transposed (hint: adapter from \"finetune\" example is no longer supported)");
}

// save tensor to adapter
struct ggml_tensor * tensor_a = ggml_dup_tensor(dev_ctx, w.a);
struct ggml_tensor * tensor_b = ggml_dup_tensor(dev_ctx, w.b);
ggml_set_name(tensor_a, w.a->name);
ggml_set_name(tensor_b, w.b->name);
adapter.ab_map[name] = llama_lora_weight(tensor_a, tensor_b);
}

// allocate tensors / buffers and zero
{
adapter.ctxs.reserve(ctx_map.size());
adapter.bufs.reserve(ctx_map.size());
for (auto & it : ctx_map) {
ggml_backend_buffer_type_t buft = it.first;
ggml_context * ctx_dev = it.second;
ggml_backend_buffer_ptr buf { ggml_backend_alloc_ctx_tensors_from_buft(ctx_dev, buft) };
if (!buf) {
throw std::runtime_error("failed to allocate buffer for lora adapter\n");
}
LLAMA_LOG_INFO("%s: %10s LoRA buffer size = %8.2f MiB\n", __func__, ggml_backend_buffer_name(buf.get()), ggml_backend_buffer_get_size(buf.get())/1024.0/1024.0);
adapter.bufs.emplace_back(std::move(buf));
}
}

// set tensor data
{
llama_file gguf_file(path_lora, "rb");
std::vector<uint8_t> read_buf;
auto set_tensor = [&](struct ggml_tensor * orig, struct ggml_tensor * dev) {
size_t offs = gguf_get_data_offset(ctx_gguf.get()) + gguf_get_tensor_offset(ctx_gguf.get(), gguf_find_tensor(ctx_gguf.get(), orig->name));
size_t size = ggml_nbytes(orig);
read_buf.resize(size);
gguf_file.seek(offs, SEEK_SET);
gguf_file.read_raw(read_buf.data(), size);
ggml_backend_tensor_set(dev, read_buf.data(), 0, size);
};
for (auto & it : adapter.ab_map) {
auto orig = ab_map[it.first];
auto dev = it.second;
set_tensor(orig.a, dev.a);
set_tensor(orig.b, dev.b);
}
}

LLAMA_LOG_INFO("%s: loaded %zu tensors from lora file\n", __func__, adapter.ab_map.size()*2);
}
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