llama : add struct llama_kv_cache (wip) [no ci]

This commit is contained in:
Georgi Gerganov
2025-01-13 14:13:11 +02:00
parent 178a7eb952
commit f78b396ee7
8 changed files with 428 additions and 415 deletions

View File

@@ -57,6 +57,16 @@ struct llama_kv_cache {
std::vector<ggml_context_ptr> ctxs;
std::vector<ggml_backend_buffer_ptr> bufs;
int32_t n_tokens() const {
int32_t result = 0;
for (uint32_t i = 0; i < size; i++) {
result += cells[i].seq_id.size();
}
return result;
}
size_t total_size() const {
size_t size = 0;
for (const auto & buf : bufs) {
@@ -75,6 +85,297 @@ struct llama_kv_cache {
return max_pos;
}
void clear() {
for (int32_t i = 0; i < (int32_t) size; ++i) {
cells[i].pos = -1;
cells[i].seq_id.clear();
cells[i].src = -1;
cells[i].tail = -1;
}
head = 0;
used = 0;
for (auto & buf : bufs) {
ggml_backend_buffer_clear(buf.get(), 0);
}
}
bool seq_rm(llama_seq_id seq_id, llama_pos p0, llama_pos p1) {
uint32_t new_head = size;
if (p0 < 0) {
p0 = 0;
}
if (p1 < 0) {
p1 = std::numeric_limits<llama_pos>::max();
}
// models like Mamba or RWKV can't have a state partially erased
if (recurrent) {
if (seq_id >= (int64_t) size) {
// could be fatal
return false;
}
if (0 <= seq_id) {
int32_t & tail_id = cells[seq_id].tail;
if (tail_id >= 0) {
const llama_kv_cell & cell = cells[tail_id];
// partial intersection is invalid
if ((0 < p0 && p0 <= cell.pos) || (0 < p1 && p1 <= cell.pos)) {
return false;
}
// invalidate tails which will be cleared
if (p0 <= cell.pos && cell.pos < p1) {
tail_id = -1;
}
}
} else {
// seq_id is negative, then the range should include everything or nothing
if (p0 != p1 && (p0 != 0 || p1 != std::numeric_limits<llama_pos>::max())) {
return false;
}
}
}
for (uint32_t i = 0; i < size; ++i) {
if (cells[i].pos >= p0 && cells[i].pos < p1) {
if (seq_id < 0) {
cells[i].seq_id.clear();
} else if (cells[i].has_seq_id(seq_id)) {
cells[i].seq_id.erase(seq_id);
} else {
continue;
}
if (cells[i].is_empty()) {
// keep count of the number of used cells
if (cells[i].pos >= 0) {
used--;
}
cells[i].pos = -1;
cells[i].src = -1;
if (new_head == size) {
new_head = i;
}
}
}
}
// If we freed up a slot, set head to it so searching can start there.
if (new_head != size && new_head < head) {
head = new_head;
}
return true;
}
void seq_cp(llama_seq_id seq_id_src, llama_seq_id seq_id_dst, llama_pos p0, llama_pos p1) {
if (seq_id_src == seq_id_dst) {
return;
}
if (p0 < 0) {
p0 = 0;
}
if (p1 < 0) {
p1 = std::numeric_limits<llama_pos>::max();
}
if (recurrent) {
if ((uint32_t) seq_id_dst < size && (uint32_t) seq_id_src < size) {
llama_kv_cell & tail_src = cells[seq_id_src];
llama_kv_cell & tail_dst = cells[seq_id_dst];
if (tail_dst.tail >= 0) {
// clear destination seq_id if it wasn't empty
llama_kv_cell & cell_dst = cells[tail_dst.tail];
cell_dst.seq_id.erase(seq_id_dst);
tail_dst.tail = -1;
if (cell_dst.seq_id.empty()) {
cell_dst.pos = -1;
cell_dst.delta = -1;
cell_dst.src = -1;
used -= 1;
}
}
if (tail_src.tail >= 0) {
llama_kv_cell & cell_src = cells[tail_src.tail];
cell_src.seq_id.insert(seq_id_dst);
tail_dst.tail = tail_src.tail;
}
}
return;
}
// otherwise, this is the KV of a Transformer-like model
head = 0;
for (uint32_t i = 0; i < size; ++i) {
if (cells[i].has_seq_id(seq_id_src) && cells[i].pos >= p0 && cells[i].pos < p1) {
cells[i].seq_id.insert(seq_id_dst);
}
}
}
void seq_keep(llama_seq_id seq_id) {
uint32_t new_head = size;
for (uint32_t i = 0; i < size; ++i) {
if (recurrent && (llama_seq_id) i != seq_id) {
cells[i].tail = -1;
}
if (!cells[i].has_seq_id(seq_id)) {
if (cells[i].pos >= 0) {
used--;
}
cells[i].pos = -1;
cells[i].src = -1;
cells[i].seq_id.clear();
if (new_head == size){
new_head = i;
}
} else {
cells[i].seq_id.clear();
cells[i].seq_id.insert(seq_id);
}
}
// If we freed up a slot, set head to it so searching can start there.
if (new_head != size && new_head < head) {
head = new_head;
}
}
void seq_add(llama_seq_id seq_id, llama_pos p0, llama_pos p1, llama_pos delta) {
if (delta == 0) {
return;
}
uint32_t new_head = size;
if (p0 < 0) {
p0 = 0;
}
if (p1 < 0) {
p1 = std::numeric_limits<llama_pos>::max();
}
// If there is no range then return early to avoid looping over the
if (p0 == p1) {
return;
}
if (recurrent) {
// for Mamba-like or RWKV models, only the pos needs to be shifted
if (0 <= seq_id && seq_id < (int64_t) size) {
const int32_t tail_id = cells[seq_id].tail;
if (tail_id >= 0) {
llama_kv_cell & cell = cells[tail_id];
if (cell.has_seq_id(seq_id) && p0 <= cell.pos && cell.pos < p1) {
cell.pos += delta;
}
}
}
return;
}
for (uint32_t i = 0; i < size; ++i) {
if (cells[i].has_seq_id(seq_id) && cells[i].pos >= p0 && cells[i].pos < p1) {
has_shift = true;
cells[i].pos += delta;
cells[i].delta += delta;
if (cells[i].pos < 0) {
if (!cells[i].is_empty()) {
used--;
}
cells[i].pos = -1;
cells[i].seq_id.clear();
if (new_head == size) {
new_head = i;
}
}
}
}
// If we freed up a slot, set head to it so searching can start there.
// Otherwise we just start the next search from the beginning.
head = new_head != size ? new_head : 0;
}
void seq_div(llama_seq_id seq_id, llama_pos p0, llama_pos p1, int d) {
if (d == 1) {
return;
}
if (p0 < 0) {
p0 = 0;
}
if (p1 < 0) {
p1 = std::numeric_limits<llama_pos>::max();
}
// If there is no range then return early to avoid looping over the cache.
if (p0 == p1) {
return;
}
if (recurrent) {
// for Mamba-like or RWKV models, only the pos needs to be changed
if (0 <= seq_id && seq_id < (int64_t) size) {
const int32_t tail_id = cells[seq_id].tail;
if (tail_id >= 0) {
llama_kv_cell & cell = cells[tail_id];
if (cell.has_seq_id(seq_id) && p0 <= cell.pos && cell.pos < p1) {
cell.pos /= d;
}
}
}
return;
}
for (uint32_t i = 0; i < size; ++i) {
if (cells[i].has_seq_id(seq_id) && cells[i].pos >= p0 && cells[i].pos < p1) {
has_shift = true;
{
llama_pos p_old = cells[i].pos;
cells[i].pos /= d;
cells[i].delta += cells[i].pos - p_old;
}
}
}
}
llama_pos seq_pos_max(llama_seq_id seq_id) {
llama_pos result = 0;
for (uint32_t i = 0; i < size; ++i) {
if (cells[i].has_seq_id(seq_id)) {
result = std::max(result, cells[i].pos);
}
}
return result;
}
void defrag() {
if (!recurrent) {
do_defrag = true;
}
}
};
// a structure holds information about the slot found in llama_kv_cache_find_slot
@@ -112,51 +413,6 @@ struct llama_kv_cache_slot_info llama_kv_cache_find_slot(
// find how many cells are currently in use
uint32_t llama_kv_cache_cell_max(const struct llama_kv_cache & cache);
void llama_kv_cache_clear(struct llama_kv_cache & cache);
bool llama_kv_cache_seq_rm(
struct llama_kv_cache & cache,
llama_seq_id seq_id,
llama_pos p0,
llama_pos p1);
void llama_kv_cache_seq_cp(
struct llama_kv_cache & cache,
llama_seq_id seq_id_src,
llama_seq_id seq_id_dst,
llama_pos p0,
llama_pos p1);
void llama_kv_cache_seq_keep(
struct llama_kv_cache & cache,
llama_seq_id seq_id);
void llama_kv_cache_seq_add(
struct llama_kv_cache & cache,
llama_seq_id seq_id,
llama_pos p0,
llama_pos p1,
llama_pos delta);
void llama_kv_cache_seq_div(
struct llama_kv_cache & cache,
llama_seq_id seq_id,
llama_pos p0,
llama_pos p1,
int d);
llama_pos llama_kv_cache_seq_pos_max(
struct llama_kv_cache & cache,
llama_seq_id seq_id);
void llama_kv_cache_defrag(struct llama_kv_cache & cache);
int32_t llama_get_kv_cache_token_count(const struct llama_kv_cache & kv);
int32_t llama_get_kv_cache_used_cells(const struct llama_kv_cache & kv);
bool llama_kv_cache_can_shift(const struct llama_kv_cache & kv);
//
// kv cache view
//
@@ -206,10 +462,10 @@ struct llama_kv_slot_restorer {
cache.n = old_state.n;
if (cache.recurrent) { // recurrent models like Mamba or RWKV can't have a state partially erased
llama_kv_cache_seq_rm(cache, -1, -1, -1);
cache.seq_rm(-1, -1, -1);
} else {
for (auto & slot : slot_boundaries) {
llama_kv_cache_seq_rm(cache, -1, slot.first, slot.second);
cache.seq_rm(-1, slot.first, slot.second);
}
}
}