Replace MLA-specific KV cache with the standard KV cache (#469)

* Remove kv_l, kvt_l and just use k_l and v_l

* Hopefully take care of missing V cache (MLA)

* Replace MLA-specific KV cache with the standard KV cache V2 (#473)

* Fix save and restore when there is no V cache

* Fix double print

---------

Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>
Co-authored-by: saood06 <saood05@gmail.com>
This commit is contained in:
Kawrakow
2025-05-30 11:08:17 +03:00
committed by GitHub
parent 1eac9e8487
commit 2cf12eb12d

View File

@@ -2991,10 +2991,6 @@ struct llama_kv_cache {
std::vector<struct ggml_tensor *> k_l; // per layer
std::vector<struct ggml_tensor *> v_l;
// DeepSeek MLA
std::vector<struct ggml_tensor *> kv_l;
std::vector<struct ggml_tensor *> kvt_l;
std::vector<struct ggml_context *> ctxs;
std::vector<ggml_backend_buffer_t> bufs;
@@ -3493,16 +3489,12 @@ static bool llama_kv_cache_init(
}
}
cache.k_l.reserve(n_layer);
bool needs_v_cache = true;
if (model.arch == LLM_ARCH_DEEPSEEK2 && cparams.mla_attn) {
// DeepSeek MLA
cache.kv_l.reserve(n_layer);
if (cparams.mla_attn == 1 && !cparams.flash_attn) {
cache.kvt_l.reserve(n_layer);
}
} else {
cache.k_l.reserve(n_layer);
cache.v_l.reserve(n_layer);
needs_v_cache = cparams.mla_attn == 1 && !cparams.flash_attn;
}
if (needs_v_cache) cache.v_l.reserve(n_layer);
bool warn = true;
int n_mla = 0;
@@ -3525,17 +3517,17 @@ static bool llama_kv_cache_init(
//LLAMA_LOG_INFO("%s: layer %d: n_embd_head_qk_rope = %d, kv_lora_rank = %d\n", __func__, i, n_embd_head_qk_rope, kv_lora_rank);
if (cparams.flash_attn) {
ggml_tensor * kv = ggml_new_tensor_2d(ctx, cache.type_k, kv_lora_rank + n_embd_head_qk_rope, kv_size);
ggml_format_name(kv, "cache_kv_l%d", i);
cache.kv_l.push_back(kv);
ggml_format_name(kv, "cache_k_l%d", i);
cache.k_l.push_back(kv);
} else {
auto kv_type = cparams.mla_attn == 1 ? cache.type_k : cache.type_v;
ggml_tensor * kv = ggml_new_tensor_2d(ctx, kv_type, kv_lora_rank + n_embd_head_qk_rope, kv_size);
ggml_format_name(kv, "cache_kv_l%d", i);
cache.kv_l.push_back(kv);
ggml_format_name(kv, "cache_k_l%d", i);
cache.k_l.push_back(kv);
if (cparams.mla_attn == 1) {
ggml_tensor * kvt = ggml_new_tensor_1d(ctx, cache.type_v, kv_lora_rank*kv_size);
ggml_format_name(kvt, "cache_kvt_l%d", i);
cache.kvt_l.push_back(kvt);
ggml_format_name(kvt, "cache_v_l%d", i);
cache.v_l.push_back(kvt);
}
}
n_mla++;
@@ -10355,34 +10347,39 @@ struct llm_build_context {
ggml_row_size(kv_self.k_l[il]->type, n_embd_k_gqa),
ggml_row_size(kv_self.k_l[il]->type, n_embd_k_gqa*id));
ggml_tensor * view_v_src;
ggml_tensor * view_v_dst;
ggml_tensor * view_v_src = nullptr;
ggml_tensor * view_v_dst = nullptr;
if (flash_attn) {
// NOTE: the V cache is not transposed when using flash attention
view_v_src = ggml_view_2d(ctx0, kv_self.v_l[il],
n_embd_v_gqa, nm,
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa),
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa*i));
if (kv_self.v_l.size() > il) {
// Note: with MLA the V cache may not be present.
if (flash_attn) {
// NOTE: the V cache is not transposed when using flash attention
view_v_src = ggml_view_2d(ctx0, kv_self.v_l[il],
n_embd_v_gqa, nm,
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa),
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa*i));
view_v_dst = ggml_view_2d(ctx0, kv_self.v_l[il],
n_embd_v_gqa, nm,
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa),
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa*id));
} else {
view_v_src = ggml_view_2d(ctx0, kv_self.v_l[il],
nm, n_embd_v_gqa,
ggml_row_size(kv_self.v_l[il]->type, kv_self.size),
ggml_row_size(kv_self.v_l[il]->type, i));
view_v_dst = ggml_view_2d(ctx0, kv_self.v_l[il],
n_embd_v_gqa, nm,
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa),
ggml_row_size(kv_self.v_l[il]->type, n_embd_v_gqa*id));
} else {
view_v_src = ggml_view_2d(ctx0, kv_self.v_l[il],
nm, n_embd_v_gqa,
ggml_row_size(kv_self.v_l[il]->type, kv_self.size),
ggml_row_size(kv_self.v_l[il]->type, i));
view_v_dst = ggml_view_2d(ctx0, kv_self.v_l[il],
nm, n_embd_v_gqa,
ggml_row_size(kv_self.v_l[il]->type, kv_self.size),
ggml_row_size(kv_self.v_l[il]->type, id));
view_v_dst = ggml_view_2d(ctx0, kv_self.v_l[il],
nm, n_embd_v_gqa,
ggml_row_size(kv_self.v_l[il]->type, kv_self.size),
ggml_row_size(kv_self.v_l[il]->type, id));
}
}
ggml_build_forward_expand(gf, ggml_cpy(ctx0, view_k_src, view_k_dst));
ggml_build_forward_expand(gf, ggml_cpy(ctx0, view_v_src, view_v_dst));
if (view_v_src && view_v_dst) {
ggml_build_forward_expand(gf, ggml_cpy(ctx0, view_v_src, view_v_dst));
}
}
i += nm - 1;
@@ -15371,16 +15368,16 @@ struct llm_build_context {
ggml_tensor * kv_cache_trans;
if (lctx.cparams.mla_attn == 1 && !lctx.cparams.flash_attn) {
ggml_tensor * kv_cache_trans_view = ggml_view_2d(ctx0, kv_self.kvt_l[il], n_tokens, kv_lora_rank,
ggml_row_size(kv_self.kvt_l[il]->type, kv_self.size), ggml_row_size(kv_self.kvt_l[il]->type, kv_head));
ggml_tensor * kv_cache_trans_view = ggml_view_2d(ctx0, kv_self.v_l[il], n_tokens, kv_lora_rank,
ggml_row_size(kv_self.v_l[il]->type, kv_self.size), ggml_row_size(kv_self.v_l[il]->type, kv_head));
cb(kv_cache_trans_view, "kv_cache_trans_view", il);
// note: storing transposed c^KV in the transposed KV cache
ggml_build_forward_expand(gf, ggml_cpy(ctx0, ggml_transpose(ctx0, kv_compressed), kv_cache_trans_view));
kv_cache_trans = ggml_view_2d(ctx0, kv_self.kvt_l[il],
kv_cache_trans = ggml_view_2d(ctx0, kv_self.v_l[il],
n_kv, kv_lora_rank,
ggml_row_size(kv_self.kvt_l[il]->type, kv_self.size),
ggml_row_size(kv_self.v_l[il]->type, kv_self.size),
0);
cb(kv_cache_trans, "kv_cache_trans", il);
}
@@ -15389,21 +15386,21 @@ struct llm_build_context {
ggml_tensor * kvr = ggml_concat(ctx0, ggml_permute(ctx0, k_rope, 0, 2, 1, 3), kv_compressed, 0);
cb(kvr, "kvr", il);
auto row_size = ggml_row_size(kv_self.kv_l[il]->type, kv_lora_rank + n_embd_head_qk_rope);
ggml_tensor * kv_cache_view = ggml_view_2d(ctx0, kv_self.kv_l[il], kv_self.kv_l[il]->ne[0], n_tokens,
auto row_size = ggml_row_size(kv_self.k_l[il]->type, kv_lora_rank + n_embd_head_qk_rope);
ggml_tensor * kv_cache_view = ggml_view_2d(ctx0, kv_self.k_l[il], kv_self.k_l[il]->ne[0], n_tokens,
row_size, row_size*kv_head);
ggml_build_forward_expand(gf, ggml_cpy(ctx0, kvr, kv_cache_view));
ggml_tensor * kv_cache = ggml_view_2d(ctx0, kv_self.kv_l[il],
ggml_tensor * kv_cache = ggml_view_2d(ctx0, kv_self.k_l[il],
kv_lora_rank + n_embd_head_qk_rope, n_kv,
ggml_row_size(kv_self.kv_l[il]->type, kv_lora_rank + n_embd_head_qk_rope), 0);
ggml_row_size(kv_self.k_l[il]->type, kv_lora_rank + n_embd_head_qk_rope), 0);
cb(kv_cache, "kv_cache", il);
ggml_tensor * kqv;
if (lctx.cparams.mla_attn > 1 && lctx.cparams.flash_attn && pp_opt) { // PP for mla=2,3
auto kv_cache_nope = ggml_view_2d(ctx0, kv_self.kv_l[il], kv_lora_rank, n_kv, kv_self.kv_l[il]->nb[1],
ggml_row_size(kv_self.kv_l[il]->type, n_embd_head_qk_rope));
auto kv_cache_nope = ggml_view_2d(ctx0, kv_self.k_l[il], kv_lora_rank, n_kv, kv_self.k_l[il]->nb[1],
ggml_row_size(kv_self.k_l[il]->type, n_embd_head_qk_rope));
auto kv_f32_size = model.layers[il].wkv_b->ne[1] * kv_cache_nope->ne[1] * sizeof(float) / (1024*1024);
int n_max_head = n_head;
@@ -15416,14 +15413,14 @@ struct llm_build_context {
auto n_per_head = model.layers[il].wkv_b->ne[1] / n_head;
auto kv_cache_rope = ggml_view_3d(ctx0, kv_self.kv_l[il], n_embd_head_qk_rope, n_kv, 1,
kv_self.kv_l[il]->nb[1], kv_self.kv_l[il]->nb[2], 0); //ggml_row_size(kv_self.kv_l[il]->type, kv_lora_rank));
auto kv_cache_rope = ggml_view_3d(ctx0, kv_self.k_l[il], n_embd_head_qk_rope, n_kv, 1,
kv_self.k_l[il]->nb[1], kv_self.k_l[il]->nb[2], 0); //ggml_row_size(kv_self.k_l[il]->type, kv_lora_rank));
// There is still an issue with one or more of the ops GGML_OP_REPEAT, GGML_OP_CONCAT, GGML_OP_CPY on CUDA when
// the KV cache is quantized. Hence, in that case we will simply use fp16 for now.
// The downside of the following line is that fp16 will be used even if attention is computed on the CPU
// if the build is with CUDA enabled.
auto kv_type = lctx.backends.size() == 1 && lctx.backends.front() == lctx.backend_cpu ? kv_self.kv_l[il]->type : GGML_TYPE_F16;
auto kv_type = lctx.backends.size() == 1 && lctx.backends.front() == lctx.backend_cpu ? kv_self.k_l[il]->type : GGML_TYPE_F16;
ggml_tensor repeater;
repeater.ne[0] = n_embd_head_qk_rope; repeater.ne[1] = n_kv; repeater.ne[2] = n_max_head; repeater.ne[3] = 1;
@@ -15514,10 +15511,10 @@ struct llm_build_context {
cb(q, "q", il);
if (lctx.cparams.flash_attn && (lctx.cparams.mla_attn == 1 || lctx.cparams.mla_attn == 3)) {
ggml_tensor * kv_cache_lora = ggml_view_2d(ctx0, kv_self.kv_l[il],
ggml_tensor * kv_cache_lora = ggml_view_2d(ctx0, kv_self.k_l[il],
kv_lora_rank, n_kv,
ggml_row_size(kv_self.kv_l[il]->type, kv_lora_rank + n_embd_head_qk_rope),
ggml_row_size(kv_self.kv_l[il]->type, n_embd_head_qk_rope));
ggml_row_size(kv_self.k_l[il]->type, kv_lora_rank + n_embd_head_qk_rope),
ggml_row_size(kv_self.k_l[il]->type, n_embd_head_qk_rope));
cb(kv_cache_lora, "kv_cache_lora", il);
kqv_compressed = ggml_flash_attn_ext(ctx0, q, kv_cache, kv_cache_lora, KQ_mask, kq_scale, hparams.f_max_alibi_bias, 0.f);
@@ -15528,10 +15525,10 @@ struct llm_build_context {
}
else {
if (lctx.cparams.mla_attn > 1) {
ggml_tensor * kv_cache_lora = ggml_view_2d(ctx0, kv_self.kv_l[il],
ggml_tensor * kv_cache_lora = ggml_view_2d(ctx0, kv_self.k_l[il],
kv_lora_rank, n_kv,
ggml_row_size(kv_self.kv_l[il]->type, kv_lora_rank + n_embd_head_qk_rope),
ggml_row_size(kv_self.kv_l[il]->type, n_embd_head_qk_rope));
ggml_row_size(kv_self.k_l[il]->type, kv_lora_rank + n_embd_head_qk_rope),
ggml_row_size(kv_self.k_l[il]->type, n_embd_head_qk_rope));
cb(kv_cache, "kv_cache_lora", il);
kv_cache_trans = ggml_cont(ctx0, ggml_transpose(ctx0, kv_cache_lora));
@@ -20702,42 +20699,21 @@ struct llama_context * llama_new_context_with_model(
}
if (memory_size_k + memory_size_v > 0) {
LLAMA_LOG_INFO("%s: KV self size = %7.2f MiB, K (%s): %7.2f MiB, V (%s): %7.2f MiB\n", __func__,
(float)(memory_size_k + memory_size_v) / (1024.0f * 1024.0f),
ggml_type_name(type_k), (float)memory_size_k / (1024.0f * 1024.0f),
ggml_type_name(type_v), (float)memory_size_v / (1024.0f * 1024.0f));
}
}
{
size_t memory_size_kv = 0;
size_t memory_size_kvt = 0;
ggml_type kv_type = GGML_TYPE_COUNT;
ggml_type kvt_type = GGML_TYPE_COUNT;
for (auto & kv : ctx->kv_self.kv_l) {
memory_size_kv += ggml_nbytes(kv);
kv_type = kv->type;
}
for (auto & kvt : ctx->kv_self.kvt_l) {
memory_size_kvt += ggml_nbytes(kvt);
kvt_type = kvt->type;
}
if (memory_size_kv + memory_size_kvt > 0) {
if (cparams.mla_attn == 1 && !cparams.flash_attn) {
if (cparams.mla_attn != 0 && !cparams.flash_attn) {
LLAMA_LOG_INFO("%s: KV self size = %7.2f MiB, c^KV (%s): %7.2f MiB, kv^T (%s): %7.2f MiB\n", __func__,
(float)(memory_size_kv + memory_size_kvt) / (1024.0f * 1024.0f),
ggml_type_name(kv_type), (float)memory_size_kv / (1024.0f * 1024.0f),
ggml_type_name(kvt_type), (float)memory_size_kvt / (1024.0f * 1024.0f));
} else {
GGML_ASSERT(memory_size_kvt == 0);
(float)(memory_size_k + memory_size_v) / (1024.0f * 1024.0f),
ggml_type_name(type_k), (float)memory_size_k / (1024.0f * 1024.0f),
ggml_type_name(type_v), (float)memory_size_v / (1024.0f * 1024.0f));
} else if (cparams.mla_attn != 0 && cparams.flash_attn) {
LLAMA_LOG_INFO("%s: KV self size = %7.2f MiB, c^KV (%s): %7.2f MiB, kv^T: not used\n", __func__,
(float)(memory_size_kv + memory_size_kvt) / (1024.0f * 1024.0f),
ggml_type_name(kv_type), (float)memory_size_kv / (1024.0f * 1024.0f));
}
(float)(memory_size_k + memory_size_v) / (1024.0f * 1024.0f),
ggml_type_name(type_k), (float)memory_size_k / (1024.0f * 1024.0f));
} else {
LLAMA_LOG_INFO("%s: KV self size = %7.2f MiB, K (%s): %7.2f MiB, V (%s): %7.2f MiB\n", __func__,
(float)(memory_size_k + memory_size_v) / (1024.0f * 1024.0f),
ggml_type_name(type_k), (float)memory_size_k / (1024.0f * 1024.0f),
ggml_type_name(type_v), (float)memory_size_v / (1024.0f * 1024.0f));
}
}
}
@@ -21454,10 +21430,13 @@ struct llama_data_write {
const struct llama_kv_cache & kv_self = ctx->kv_self;
const struct llama_hparams & hparams = ctx->model.hparams;
const uint32_t v_trans = kv_self.v_trans ? 1 : 0;
// v_state: 0 -> not transposed V cache
// 1 -> transposed V cache
// 2 -> no V cache (as it may be the case with MLA)
const uint32_t v_state = kv_self.v_l.empty() ? 2 : kv_self.v_trans ? 1 : 0;
const uint32_t n_layer = hparams.n_layer;
write(&v_trans, sizeof(v_trans));
write(&v_state, sizeof(v_state));
write(&n_layer, sizeof(n_layer));
std::vector<uint8_t> tmp_buf;
@@ -21483,7 +21462,7 @@ struct llama_data_write {
}
}
if (!kv_self.v_trans) {
if (v_state == 0) {
for (uint32_t il = 0; il < n_layer; ++il) {
const uint32_t n_embd_v_gqa = hparams.n_embd_v_gqa(il) + hparams.n_embd_v_s();
@@ -21502,7 +21481,8 @@ struct llama_data_write {
write_tensor_data(kv_self.v_l[il], range.first * v_size_row, buf_size);
}
}
} else {
}
else if (v_state == 1) {
// When v is transposed, we also need the element size and get the element ranges from each row
const uint32_t kv_size = kv_self.size;
for (uint32_t il = 0; il < n_layer; ++il) {
@@ -21748,9 +21728,13 @@ struct llama_data_read {
bool read_kv_cache_data(struct llama_context * ctx, uint32_t cell_count) {
const struct llama_hparams & hparams = ctx->model.hparams;
struct llama_kv_cache & kv_self = ctx->kv_self;
uint32_t v_trans;
// v_state: 0 -> not transposed V cache
// 1 -> transposed V cache
// 2 -> no V cache (as it may be the case with MLA)
uint32_t v_state;
uint32_t n_layer;
read_to(&v_trans, sizeof(v_trans));
read_to(&v_state, sizeof(v_state));
read_to(&n_layer, sizeof(n_layer));
if (n_layer != hparams.n_layer) {
@@ -21761,7 +21745,9 @@ struct llama_data_read {
LLAMA_LOG_ERROR("%s: not enough cells in kv cache to restore state (%u > %u)\n", __func__, cell_count, kv_self.size);
return false;
}
if (kv_self.v_trans != (bool) v_trans) {
// Currently the only way there is no V cache (and thus v_state is 2) requires flash_attn, and flash_attn sets kv_self.v_trans to false
if (kv_self.v_trans != (v_state == 1)) {
LLAMA_LOG_ERROR("%s: incompatible V transposition\n", __func__);
return false;
}
@@ -21794,7 +21780,7 @@ struct llama_data_read {
}
}
if (!kv_self.v_trans) {
if (v_state == 0) {
for (uint32_t il = 0; il < n_layer; ++il) {
const uint32_t n_embd_v_gqa = hparams.n_embd_v_gqa(il) + hparams.n_embd_v_s();
@@ -21821,7 +21807,8 @@ struct llama_data_read {
ggml_backend_tensor_set(kv_self.v_l[il], read(cell_count * v_size_row), kv_self.head * v_size_row, cell_count * v_size_row);
}
}
} else {
}
else if (v_state == 1) {
// For each layer, read the values for each cell (transposed)
for (uint32_t il = 0; il < n_layer; ++il) {
const uint32_t n_embd_v_gqa = hparams.n_embd_v_gqa(il) + hparams.n_embd_v_s();