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Add support for memory mapping models #586

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9 changes: 6 additions & 3 deletions ggml.c
Original file line number Diff line number Diff line change
Expand Up @@ -2419,8 +2419,9 @@ struct ggml_context {
void * mem_buffer;
bool mem_buffer_owned;
bool mem_buffer_mlocked;
bool no_alloc;

int n_objects;
int n_objects;

struct ggml_object * objects_begin;
struct ggml_object * objects_end;
Expand Down Expand Up @@ -2702,6 +2703,7 @@ struct ggml_context * ggml_init(struct ggml_init_params params) {
/*.mem_buffer =*/ params.mem_buffer ? params.mem_buffer : malloc(params.mem_size),
/*.mem_buffer_owned =*/ params.mem_buffer ? false : true,
/*.mem_buffer_mlocked =*/ false,
/*.no_alloc =*/ params.no_alloc,
/*.n_objects =*/ 0,
/*.objects_begin =*/ NULL,
/*.objects_end =*/ NULL,
Expand Down Expand Up @@ -2817,7 +2819,7 @@ struct ggml_tensor * ggml_new_tensor_impl(

size_t size_needed = 0;

if (data == NULL) {
if (data == NULL && !ctx->no_alloc) {
size_needed += GGML_TYPE_SIZE[type]*(ne[0]/GGML_BLCK_SIZE[type]);
for (int i = 1; i < n_dims; i++) {
size_needed *= ne[i];
Expand Down Expand Up @@ -2901,7 +2903,7 @@ struct ggml_tensor * ggml_new_tensor_impl(
/*.perf_runs =*/ 0,
/*.perf_cycles =*/ 0,
/*.perf_time_us =*/ 0,
/*.data =*/ data == NULL ? (void *)(result + 1) : data,
/*.data =*/ (data == NULL && !ctx->no_alloc) ? (void *)(result + 1) : data,
/*.pad =*/ { 0 },
};

Expand Down Expand Up @@ -10164,6 +10166,7 @@ enum ggml_opt_result ggml_opt(
struct ggml_init_params params_ctx = {
.mem_size = 16*1024*1024,
.mem_buffer = NULL,
.no_alloc = false,
};

ctx = ggml_init(params_ctx);
Expand Down
1 change: 1 addition & 0 deletions ggml.h
Original file line number Diff line number Diff line change
Expand Up @@ -316,6 +316,7 @@ struct ggml_init_params {
// memory pool
size_t mem_size; // bytes
void * mem_buffer; // if NULL, memory will be allocated internally
bool no_alloc; // don't allocate memory for the tensor data
};

void ggml_time_init(void); // call this once at the beginning of the program
Expand Down
86 changes: 67 additions & 19 deletions llama.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,13 @@
#include <cassert>
#include <cstring>

// headers for POSIX mmap
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@CoderRC CoderRC Mar 29, 2023

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Recommended:
#ifdef __has_include
#if __has_include(<sys/mman.h>)
#include <sys/mman.h>
#endif
#if __has_include(<fcntl.h>)
#include <fcntl.h>
#endif
#if __has_include(<unistd.h>)
#include <unistd.h>
#endif
#elif defined (unix) || defined (APPLE)

include <sys/mman.h>

include <fcntl.h>

include <unistd.h>

#endif
Due to:
ggml.c line 101
#ifdef __has_include
#if __has_include(<sys/mman.h>)
#undef GGML_MLOCK_SUPPORT
#define GGML_MLOCK_SUPPORT 1
#include <sys/mman.h>
#endif
#endif

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ggml.c is C, but this is C++ however and currently we are compiling with -std=c++11, and __has_include is C++17. Do you know of any platforms that may fail with the current implementation?

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The thing is it would not fail with any platforms because #ifdef __has_include will ignore the definition if __has_include macro does not exist.

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I understand, but in practical terms what are the advantages of doing that instead? Do you know of any specific platform that may fail with the current code?

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@CoderRC CoderRC Mar 29, 2023

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The advantages are if a person created their own implementation of mmap the code will use their implementation instead, and it decreases the amount of work to support another platform.

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@CoderRC I've created a new mmap() pull request #613 that's rebased on this change. I took special care to make sure your mmap preprocessor macro is included. Please take a look!

#if defined (__unix__) || defined (__APPLE__)
# include <sys/mman.h>
# include <fcntl.h>
# include <unistd.h>
#endif

#define LLAMA_USE_SCRATCH
#define LLAMA_MAX_SCRATCH_BUFFERS 16

Expand Down Expand Up @@ -246,6 +253,7 @@ static bool kv_cache_init(
struct ggml_init_params params;
params.mem_size = cache.buf.size();
params.mem_buffer = cache.buf.data();
params.no_alloc = false;

cache.ctx = ggml_init(params);

Expand Down Expand Up @@ -288,6 +296,26 @@ struct llama_context_params llama_context_default_params() {
// model loading
//

void * mmap_file(const char* fname) {
#if defined(MAP_FAILED)
// POSIX mmap
int fd = open(fname, O_RDONLY);
size_t len = lseek(fd, 0, SEEK_END);
void * mm_addr = mmap(NULL, len, PROT_READ, MAP_SHARED, fd, 0);
if (mm_addr == MAP_FAILED) {
perror("mmap failed");
mm_addr = NULL;
}
close(fd);
return mm_addr;
#else
// TODO: windows support
(void)(fname); // suppress warnings
return NULL;
#endif
}


static bool llama_model_load(
const std::string & fname,
llama_context & lctx,
Expand All @@ -303,6 +331,7 @@ static bool llama_model_load(

lctx.t_start_us = t_start_us;

// TODO: this could probably be smaller when using mmap
std::vector<char> f_buf(1024*1024);

auto & model = lctx.model;
Expand Down Expand Up @@ -449,39 +478,49 @@ static bool llama_model_load(
}
}

bool use_mmap = (n_parts == 1);

// try to memory map the model file
void* mm_addr = NULL;
if (use_mmap) {
mm_addr = mmap_file(fname.c_str());
if (mm_addr == NULL) {
use_mmap = false;
}
}



auto & ctx = model.ctx;

size_t ctx_size = 0;

{
const auto & hparams = model.hparams;

const int n_embd = hparams.n_embd;
const int n_layer = hparams.n_layer;
const int n_ctx = hparams.n_ctx;
const int n_vocab = hparams.n_vocab;

ctx_size += n_embd*n_vocab*ggml_type_sizef(vtype); // tok_embeddings
if (!use_mmap) {
ctx_size += n_embd*n_vocab*ggml_type_sizef(vtype); // tok_embeddings

ctx_size += n_embd*ggml_type_sizef(GGML_TYPE_F32); // norm
ctx_size += n_embd*ggml_type_sizef(GGML_TYPE_F32); // norm

ctx_size += n_embd*n_vocab*ggml_type_sizef(vtype); // output
ctx_size += n_embd*n_vocab*ggml_type_sizef(vtype); // output

ctx_size += n_layer*(n_embd*ggml_type_sizef(GGML_TYPE_F32)); // attention_norm
ctx_size += n_layer*(n_embd*ggml_type_sizef(GGML_TYPE_F32)); // attention_norm

ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wq
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wk
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wv
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wo
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wq
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wk
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wv
ctx_size += n_layer*(n_embd*n_embd*ggml_type_sizef(wtype)); // wo

ctx_size += n_layer*(n_embd*ggml_type_sizef(GGML_TYPE_F32)); // ffn_norm
ctx_size += n_layer*(n_embd*ggml_type_sizef(GGML_TYPE_F32)); // ffn_norm

ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w1
ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w2
ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w3

ctx_size += n_ctx*n_layer*n_embd*ggml_type_sizef(memory_type); // memory_k
ctx_size += n_ctx*n_layer*n_embd*ggml_type_sizef(memory_type); // memory_v
ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w1
ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w2
ctx_size += n_layer*(n_ff*n_embd*ggml_type_sizef(wtype)); // w3
}

ctx_size += (5 + 10*n_layer)*256; // object overhead

Expand Down Expand Up @@ -514,6 +553,7 @@ static bool llama_model_load(
struct ggml_init_params params = {
/*.mem_size =*/ lctx.model.buf.size(),
/*.mem_buffer =*/ lctx.model.buf.data(),
/*.no_alloc =*/ use_mmap,
};

model.ctx = ggml_init(params);
Expand Down Expand Up @@ -595,7 +635,7 @@ static bool llama_model_load(
fname_part += "." + std::to_string(i);
}

fprintf(stderr, "%s: loading model part %d/%d from '%s'\n", __func__, i+1, n_parts, fname_part.c_str());
fprintf(stderr, "%s: loading model part %d/%d from '%s'%s\n", __func__, i+1, n_parts, fname_part.c_str(), use_mmap ? " (memory mapped)" : "");

fin = std::ifstream(fname_part, std::ios::binary);
fin.rdbuf()->pubsetbuf(f_buf.data(), f_buf.size());
Expand Down Expand Up @@ -736,7 +776,14 @@ static bool llama_model_load(
}

if (part_id == 0) {
fin.read(reinterpret_cast<char *>(tensor->data), ggml_nbytes(tensor));
if (mm_addr) {
off_t offset = fin.tellg();
tensor->data = (char *) mm_addr + offset;
fin.seekg(ggml_nbytes(tensor), std::ios::cur);
}
else {
fin.read(reinterpret_cast<char *>(tensor->data), ggml_nbytes(tensor));
}
} else {
fin.seekg(ggml_nbytes(tensor), std::ios::cur);
}
Expand Down Expand Up @@ -849,6 +896,7 @@ static bool llama_eval_internal(
struct ggml_init_params params = {
/*.mem_size =*/ buf_compute.size(),
/*.mem_buffer =*/ buf_compute.data(),
/*.no_alloc =*/ false,
};

struct ggml_context * ctx0 = ggml_init(params);
Expand Down