Adding agray3's graph caching approach

This commit is contained in:
Iwan Kawrakow
2024-10-18 18:01:08 +03:00
parent 03cabe1540
commit 0e76d21b96
4 changed files with 161 additions and 13 deletions

View File

@@ -232,6 +232,12 @@ extern "C" {
GGML_API void ggml_backend_tensor_alloc(ggml_backend_buffer_t buffer, struct ggml_tensor * tensor, void * addr);
GGML_API void ggml_backend_view_init(struct ggml_tensor * tensor);
// Utility to query whether cached GGML graph is in use
GGML_API bool ggml_use_cached_graph(ggml_backend_sched_t sched);
// Set whether or not to use GGML graph caching
GGML_API void ggml_set_cached_graph(ggml_backend_sched_t sched, bool set_value);
#ifdef __cplusplus
}

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@@ -597,6 +597,13 @@ extern "C" {
GGML_TENSOR_FLAG_PARAM = 4,
};
// Flag (used on GGML_OP_CPY nodes) on whether node is associated with K or V cache
enum ggml_kv_cache_flag {
GGML_KV_CACHE_FLAG_NONE = 0,
GGML_KV_CACHE_FLAG_K = 1,
GGML_KV_CACHE_FLAG_V = 2
};
// ggml object
struct ggml_object {
size_t offs;

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@@ -1040,6 +1040,13 @@ struct ggml_backend_sched_split {
struct ggml_cgraph graph;
};
// Object to facilitate GML graph caching
struct ggml_cached_graph {
bool is_active;
ggml_backend_t input_backend;
struct ggml_tensor * input_cpy[GGML_SCHED_MAX_SPLIT_INPUTS];
};
struct ggml_backend_sched {
bool is_reset; // true if the scheduler has been reset since the last graph split
bool is_alloc;
@@ -1085,6 +1092,8 @@ struct ggml_backend_sched {
size_t context_buffer_size;
bool debug;
struct ggml_cached_graph cached_graph;
};
#define hash_id(tensor) ggml_hash_find_or_insert(&sched->hash_set, tensor)
@@ -1762,6 +1771,14 @@ static enum ggml_status ggml_backend_sched_compute_splits(ggml_backend_sched_t s
struct ggml_tensor * input = split->inputs[j];
struct ggml_tensor * input_cpy = tensor_copy(input, split_backend_id, sched->cur_copy);
if (!sched->cached_graph.is_active) {
sched->cached_graph.input_backend = input_backend;
sched->cached_graph.input_cpy[j] = input_cpy;
} else {
input_backend = sched->cached_graph.input_backend;
input_cpy = sched->cached_graph.input_cpy[j];
}
if (input->flags & GGML_TENSOR_FLAG_INPUT) {
// inputs from the user must be copied immediately to prevent the user overwriting the data before the copy is done
if (sched->events[split_backend_id][sched->cur_copy] != NULL) {
@@ -1893,6 +1910,8 @@ ggml_backend_sched_t ggml_backend_sched_new(
ggml_backend_sched_reset(sched);
sched->cached_graph.is_active = false;
return sched;
}
@@ -1969,16 +1988,16 @@ enum ggml_status ggml_backend_sched_graph_compute(ggml_backend_sched_t sched, st
}
enum ggml_status ggml_backend_sched_graph_compute_async(ggml_backend_sched_t sched, struct ggml_cgraph * graph) {
if (!sched->is_reset && !sched->is_alloc) {
ggml_backend_sched_reset(sched);
}
if (!sched->is_alloc) {
if (!ggml_backend_sched_alloc_graph(sched, graph)) {
return GGML_STATUS_ALLOC_FAILED;
if(!sched->cached_graph.is_active) {
if (!sched->is_reset && !sched->is_alloc) {
ggml_backend_sched_reset(sched);
}
if (!sched->is_alloc) {
if (!ggml_backend_sched_alloc_graph(sched, graph)) {
return GGML_STATUS_ALLOC_FAILED;
}
}
}
return ggml_backend_sched_compute_splits(sched);
}
@@ -2243,3 +2262,13 @@ bool ggml_backend_compare_graph_backend(ggml_backend_t backend1, ggml_backend_t
return true;
}
bool ggml_use_cached_graph(ggml_backend_sched_t sched) {
return sched->cached_graph.is_active;
}
void ggml_set_cached_graph(ggml_backend_sched_t sched, bool set_value) {
sched->cached_graph.is_active = set_value;
}

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@@ -8,6 +8,7 @@
#include "ggml.h"
#include "ggml-alloc.h"
#include "ggml-backend.h"
#include "../ggml/src/ggml-impl.h"
#ifdef GGML_USE_RPC
# include "ggml-rpc.h"
@@ -2659,6 +2660,17 @@ struct llama_model {
}
};
// Object used to allow caching of GGML graph between tokens where possible.
struct ggml_cached_graph {
bool is_active = false;
ggml_cgraph * gf;
size_t n;
ggml_backend_t backend_res;
ggml_backend_t backend_embd;
struct ggml_tensor * res;
struct ggml_tensor * embd;
};
struct llama_context {
llama_context(const llama_model & model)
: model(model)
@@ -2759,6 +2771,8 @@ struct llama_context {
struct ggml_tensor * inp_pos_bucket; // I32 [n_batch|n_kv, n_batch]
struct ggml_tensor * inp_embd_enc; // F32 [n_embd, n_outputs_enc]
struct ggml_tensor * inp_KQ_mask_cross; // F32 [n_outputs_enc, n_batch]
struct ggml_cached_graph cached_graph;
};
struct llama_lora_weight {
@@ -14872,11 +14886,44 @@ static int llama_decode_internal(
ggml_backend_sched_reset(lctx.sched);
ggml_backend_sched_set_eval_callback(lctx.sched, lctx.cparams.cb_eval, lctx.cparams.cb_eval_user_data);
ggml_cgraph * gf = llama_build_graph(lctx, u_batch, false);
ggml_cgraph * gf;
// the output is always the last tensor in the graph
struct ggml_tensor * res;
struct ggml_tensor * embd;
bool n_has_changed_since_last_token = false;
if(lctx.cached_graph.n != kv_self.n) n_has_changed_since_last_token = true;
lctx.cached_graph.n = kv_self.n;
// Re-build graph only if graph caching is not possible
if(!ggml_use_cached_graph(lctx.sched) || n_has_changed_since_last_token) {
gf = llama_build_graph(lctx, u_batch, false);
// Set whether GGML graph caching is in use within GGML module, based on
// whether caching was activated here during the previous token
ggml_set_cached_graph(lctx.sched,lctx.cached_graph.is_active);
// Disable future graph caching in presence of env var,
// if there are multiple devices, if batch size is greater than 1,
// or if nsplits is not 2.
// TO DO enable graph caching for these cases
bool disable_cached_ggml_graph = (getenv("GGML_DISABLE_GRAPH_CACHING") != nullptr)
|| (llama_get_device_count(model) > 1)
|| (ggml_backend_sched_get_n_splits(lctx.sched) != 2);
for (int i = 0 ; i < gf->n_nodes; i++) {
if (gf->nodes[i]->op == GGML_OP_ADD && gf->nodes[i]->src[1] && gf->nodes[i]->src[1]->ne[1] > 1) {
disable_cached_ggml_graph = true;
break;
}
}
// Set whether graph caching should be used for future tokens
lctx.cached_graph.is_active=!disable_cached_ggml_graph;
// the output is always the last tensor in the graph
struct ggml_tensor * res = gf->nodes[gf->n_nodes - 1];
struct ggml_tensor * embd = gf->nodes[gf->n_nodes - 2];
res = gf->nodes[gf->n_nodes - 1];
embd = gf->nodes[gf->n_nodes - 2];
if (lctx.n_outputs == 0) {
// no output
@@ -14896,9 +14943,58 @@ static int llama_decode_internal(
embd = nullptr; // do not extract embeddings when not needed
GGML_ASSERT(strcmp(res->name, "result_output") == 0 && "missing result_output tensor");
}
lctx.cached_graph.res = res;
lctx.cached_graph.embd = embd;
// LLAMA_LOG_INFO("graph build time: %.3f ms (%d nodes, %d leafs)\n", (ggml_time_us() - t_start_us)/1000.0, gf->n_nodes, gf->n_leafs);
ggml_backend_sched_alloc_graph(lctx.sched, gf);
}
else {
gf = lctx.cached_graph.gf;
res = lctx.cached_graph.res;
embd = lctx.cached_graph.embd;
}
lctx.cached_graph.gf = gf;
// Update K and V cache parameters in cached graph.
if(gf != nullptr && gf->nodes != nullptr && ggml_use_cached_graph(lctx.sched)) {
const struct llama_hparams & hparams = model.hparams;
const int64_t kv_head = kv_self.head;
for (int i = 0; i < gf->n_nodes; i++) {
ggml_tensor * node = gf->nodes[i];
if (node->op == GGML_OP_CPY) {
// K cache
const char* k_prefix = "k_cache_view-";
if (strncmp(node->src[1]->name, k_prefix, strlen(k_prefix)) == 0) {
int il = atoi(node->src[1]->name + strlen(k_prefix)); // Layer index from name
const int64_t n_embd_k_gqa = hparams.n_embd_k_gqa(il);
ggml_tensor * tmp_tensor = kv_self.k_l[il];
size_t tmp_offset = (ggml_row_size(kv_self.k_l[il]->type, n_embd_k_gqa))*kv_head;
node->src[1]->data = static_cast<char*>(tmp_tensor->data) + tmp_offset;
}
// V cache
const char* v_prefix = "v_cache_view-";
if (strncmp(node->src[1]->name, v_prefix, strlen(v_prefix)) == 0) {
int il = atoi(node->src[1]->name + strlen(v_prefix)); // Layer index from name
const int64_t n_embd_v_gqa = hparams.n_embd_v_gqa(il);
ggml_tensor * tmp_tensor = kv_self.v_l[il];
size_t tmp_offset;
if (cparams.flash_attn) {
tmp_offset = (kv_head)*ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa);
} else {
tmp_offset = (kv_head)*ggml_element_size(kv_self.v_l[il]);
}
node->src[1]->data = static_cast<char*>(tmp_tensor->data) + tmp_offset;
}
}
}
}
llama_set_inputs(lctx, u_batch);
@@ -14922,12 +15018,18 @@ static int llama_decode_internal(
// extract logits
if (res) {
ggml_backend_t backend_res = ggml_backend_sched_get_tensor_backend(lctx.sched, res);
GGML_ASSERT(backend_res != nullptr);
GGML_ASSERT(lctx.logits != nullptr);
float * logits_out = lctx.logits + n_outputs_prev*n_vocab;
const int32_t n_outputs_new = lctx.n_outputs;
if(!ggml_use_cached_graph(lctx.sched))
lctx.cached_graph.backend_res = backend_res;
else
backend_res = lctx.cached_graph.backend_res;
GGML_ASSERT(backend_res != nullptr);
GGML_ASSERT(lctx.logits != nullptr);
if (n_outputs_new) {
GGML_ASSERT( n_outputs_prev + n_outputs_new <= n_outputs);
GGML_ASSERT((n_outputs_prev + n_outputs_new)*n_vocab <= (int64_t) lctx.logits_size);
@@ -14938,6 +15040,10 @@ static int llama_decode_internal(
// extract embeddings
if (embd) {
ggml_backend_t backend_embd = ggml_backend_sched_get_tensor_backend(lctx.sched, embd);
if(!ggml_use_cached_graph(lctx.sched))
lctx.cached_graph.backend_embd = backend_embd;
else
backend_embd = lctx.cached_graph.backend_embd;
GGML_ASSERT(backend_embd != nullptr);
switch (cparams.pooling_type) {