Files
llama.cpp/src/llama-memory-hybrid.cpp
T
Daniel Han 1b599101d2 llama: give the qwen4exp indexer cache the attention cache's slots
The indexer cache found its own slots, independently of the attention
cache. Both are the same size and see the same ubatches, so in a
straight-through prefill they agree, which is why every fixture and every
single-shot parity run passed. They drift once the context is being
rewritten between turns, and then the QSA top-k indices, which are applied
against the attention mask, point at the wrong cells.

The seven-turn chat test caught it on the third turn: llama-server aborted
on the assertion that the two caches report the same n_kv.

The cache is a side buffer addressed by the attention cache's cells, so it
now takes that cache's slot layout instead of computing one. Applying that
layout also marks its cells identically, so the two agree cell for cell by
construction rather than by coincidence, and the assertion can no longer
fire.

Inert where the caches already agreed: test-llama-archs green at 126 archs
and 0.00e+00, and the 4096-token tiny fixture is unchanged at max logit
delta 0.0.
2026-08-26 13:40:52 +00:00

322 lines
11 KiB
C++

#include "llama-memory-hybrid.h"
#include "llama-impl.h"
#include "llama-model.h"
#include "llama-context.h"
//
// llama_memory_hybrid
//
llama_memory_hybrid::llama_memory_hybrid(
const llama_model & model,
/* attn */
ggml_type type_k,
ggml_type type_v,
bool v_trans,
uint32_t kv_size,
uint32_t n_pad,
uint32_t n_swa,
llama_swa_type swa_type,
/* recurrent */
ggml_type type_r,
ggml_type type_s,
uint32_t rs_size,
/* common */
uint32_t n_seq_max,
uint32_t n_rs_seq,
bool offload,
bool unified,
/* layer filters */
const layer_filter_cb & filter_attn,
const layer_filter_cb & filter_recr,
const layer_filter_cb & filter_idx) :
hparams(model.hparams),
hparams_idx(model.hparams),
mem_attn(new llama_kv_cache(
model,
model.hparams,
type_k,
type_v,
v_trans,
offload,
unified,
kv_size,
n_seq_max,
n_pad,
n_swa,
swa_type,
nullptr,
filter_attn == nullptr ?
[&](int32_t il) { return !hparams.is_recr(il); }
: filter_attn,
nullptr,
nullptr
)),
mem_recr(new llama_memory_recurrent(
model,
type_r,
type_s,
offload,
rs_size,
n_seq_max,
n_rs_seq,
filter_recr == nullptr ?
[&](int32_t il) { return hparams.is_recr(il); }
: filter_recr
)),
mem_idx(filter_idx == nullptr ? nullptr : [&] {
// MQA with a single key head of indexer_head_size, as llama_kv_cache_dsa shapes its own
std::fill(hparams_idx.n_head_kv_arr.begin(), hparams_idx.n_head_kv_arr.end(), 1);
hparams_idx.n_embd_head_k_full = model.hparams.indexer_head_size;
LLAMA_LOG_INFO("%s: creating indexer KV cache, size = %u cells\n", __func__, kv_size);
return new llama_kv_cache(
model, hparams_idx, type_k, type_v, v_trans, offload, unified,
kv_size, n_seq_max, n_pad, n_swa, swa_type,
nullptr, filter_idx, nullptr, nullptr);
}()) {}
llama_memory_context_ptr llama_memory_hybrid::init_batch(llama_batch_allocr & balloc, uint32_t n_ubatch, bool embd_all) {
do {
balloc.split_reset();
// follow the recurrent pattern for creating the ubatch splits
std::vector<llama_ubatch> ubatches;
while (true) {
llama_ubatch ubatch;
if (embd_all) {
// if all tokens are output, split by sequence
ubatch = balloc.split_seq(n_ubatch);
} else {
// Use non-sequential split when KV cache is unified (needed for hellaswag/winogrande/multiple-choice)
const bool unified = (mem_attn->get_n_stream() == 1);
// [TAG_RECURRENT_ROLLBACK_SPLITS]
// the trailing (1 + n_rs_seq) tokens of each seq must stay in the same ubatch
// so that the rollback snapshots remain valid
const uint32_t n_rs_seq = mem_recr->n_rs_seq;
ubatch = balloc.split_equal(n_ubatch, !unified, n_rs_seq > 0 ? n_rs_seq + 1 : 0);
}
if (ubatch.n_tokens == 0) {
break;
}
ubatches.push_back(std::move(ubatch)); // NOLINT
}
if (balloc.get_n_used() < balloc.get_n_tokens()) {
// failed to find a suitable split
break;
}
// prepare the recurrent batches first
if (!mem_recr->prepare(ubatches)) {
// TODO: will the recurrent cache be in an undefined context at this point?
LLAMA_LOG_ERROR("%s: failed to prepare recurrent ubatches\n", __func__);
return std::make_unique<llama_memory_hybrid_context>(LLAMA_MEMORY_STATUS_FAILED_PREPARE);
}
// prepare the attention cache
auto heads_attn = mem_attn->prepare(ubatches);
if (heads_attn.empty()) {
LLAMA_LOG_ERROR("%s: failed to prepare attention ubatches\n", __func__);
return std::make_unique<llama_memory_hybrid_context>(LLAMA_MEMORY_STATUS_FAILED_PREPARE);
}
// The indexer cache is a side buffer addressed by the attention cache's cells, so it
// takes that slot layout rather than finding its own. Allocating separately let the
// two drift once context was rewritten between turns, pointing QSA top-k at the
// wrong cells.
llama_kv_cache::slot_info_vec_t heads_idx;
if (mem_idx) {
heads_idx = heads_attn;
}
return std::make_unique<llama_memory_hybrid_context>(
this, std::move(heads_attn), std::move(heads_idx), std::move(ubatches));
} while(false);
return std::make_unique<llama_memory_hybrid_context>(LLAMA_MEMORY_STATUS_FAILED_PREPARE);
}
llama_memory_context_ptr llama_memory_hybrid::init_full() {
return std::make_unique<llama_memory_hybrid_context>(this);
}
llama_memory_context_ptr llama_memory_hybrid::init_update(llama_context * lctx, bool optimize) {
return std::make_unique<llama_memory_hybrid_context>(this, lctx, optimize);
}
bool llama_memory_hybrid::get_can_shift() const {
// Shifting is trivially supported for recurrent
return mem_attn->get_can_shift();
}
void llama_memory_hybrid::clear(bool data) {
mem_attn->clear(data);
if (mem_idx) mem_idx->clear(data);
mem_recr->clear(data);
}
bool llama_memory_hybrid::seq_rm(llama_seq_id seq_id, llama_pos p0, llama_pos p1) {
// Try removing from the recurrent cache first since it may fail. If it does
// fail, the cache will not have been mutated.
if (!mem_recr->seq_rm(seq_id, p0, p1)) {
return false;
}
if (mem_idx) mem_idx->seq_rm(seq_id, p0, p1);
return mem_attn->seq_rm(seq_id, p0, p1);
}
void llama_memory_hybrid::seq_cp(llama_seq_id seq_id_src, llama_seq_id seq_id_dst, llama_pos p0, llama_pos p1) {
mem_attn->seq_cp(seq_id_src, seq_id_dst, p0, p1);
if (mem_idx) mem_idx->seq_cp(seq_id_src, seq_id_dst, p0, p1);
mem_recr->seq_cp(seq_id_src, seq_id_dst, p0, p1);
}
void llama_memory_hybrid::seq_keep(llama_seq_id seq_id) {
mem_attn->seq_keep(seq_id);
if (mem_idx) mem_idx->seq_keep(seq_id);
mem_recr->seq_keep(seq_id);
}
void llama_memory_hybrid::seq_add(llama_seq_id seq_id, llama_pos p0, llama_pos p1, llama_pos shift) {
mem_attn->seq_add(seq_id, p0, p1, shift);
if (mem_idx) mem_idx->seq_add(seq_id, p0, p1, shift);
mem_recr->seq_add(seq_id, p0, p1, shift);
}
void llama_memory_hybrid::seq_div(llama_seq_id seq_id, llama_pos p0, llama_pos p1, int d) {
mem_attn->seq_div(seq_id, p0, p1, d);
if (mem_idx) mem_idx->seq_div(seq_id, p0, p1, d);
mem_recr->seq_div(seq_id, p0, p1, d);
}
llama_pos llama_memory_hybrid::seq_pos_min(llama_seq_id seq_id) const {
// the min of the total cache is the max of the two caches' min values
return std::max(mem_attn->seq_pos_min(seq_id), mem_recr->seq_pos_min(seq_id));
}
llama_pos llama_memory_hybrid::seq_pos_max(llama_seq_id seq_id) const {
// the max of the total cache is the min of the two caches' max values
return std::min(mem_attn->seq_pos_max(seq_id), mem_recr->seq_pos_max(seq_id));
}
std::map<ggml_backend_buffer_type_t, size_t> llama_memory_hybrid::memory_breakdown() const {
std::map<ggml_backend_buffer_type_t, size_t> mb = mem_attn->memory_breakdown();
for (const auto & buft_size : mem_recr->memory_breakdown()) {
mb[buft_size.first] += buft_size.second;
}
return mb;
}
void llama_memory_hybrid::state_write(llama_io_write_i & io, llama_seq_id seq_id, llama_state_seq_flags flags) const {
if ((flags & LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY) == 0) {
mem_attn->state_write(io, seq_id, flags);
}
mem_recr->state_write(io, seq_id, flags);
}
void llama_memory_hybrid::state_read(llama_io_read_i & io, llama_seq_id seq_id, llama_state_seq_flags flags) {
if ((flags & LLAMA_STATE_SEQ_FLAGS_PARTIAL_ONLY) == 0) {
mem_attn->state_read(io, seq_id, flags);
}
mem_recr->state_read(io, seq_id, flags);
}
llama_kv_cache * llama_memory_hybrid::get_mem_attn() const {
return mem_attn.get();
}
llama_kv_cache * llama_memory_hybrid::get_mem_idx() const {
return mem_idx.get();
}
llama_memory_recurrent * llama_memory_hybrid::get_mem_recr() const {
return mem_recr.get();
}
llama_memory_hybrid_context::llama_memory_hybrid_context(llama_memory_status status) : status(status) {}
llama_memory_hybrid_context::llama_memory_hybrid_context(llama_memory_hybrid * mem) :
ctx_attn(mem->get_mem_attn()->init_full()),
ctx_recr(mem->get_mem_recr()->init_full()),
status(llama_memory_status_combine(ctx_attn->get_status(), ctx_recr->get_status())) {
}
llama_memory_hybrid_context::llama_memory_hybrid_context(
llama_memory_hybrid * mem,
llama_context * lctx,
bool optimize) :
ctx_attn(mem->get_mem_attn()->init_update(lctx, optimize)),
ctx_recr(mem->get_mem_recr()->init_update(lctx, optimize)),
status(llama_memory_status_combine(ctx_attn->get_status(), ctx_recr->get_status())) {
}
llama_memory_hybrid_context::llama_memory_hybrid_context(
llama_memory_hybrid * mem,
slot_info_vec_t sinfos_attn,
slot_info_vec_t sinfos_idx,
std::vector<llama_ubatch> ubatches) :
ubatches(std::move(ubatches)),
// note: here we copy the ubatches. not sure if this is ideal
ctx_attn(new llama_kv_cache_context(mem->get_mem_attn(), std::move(sinfos_attn), this->ubatches)),
ctx_recr(new llama_memory_recurrent_context(mem->get_mem_recr(), this->ubatches)),
ctx_idx(mem->get_mem_idx() == nullptr ? nullptr :
new llama_kv_cache_context(mem->get_mem_idx(), std::move(sinfos_idx), this->ubatches)),
status(llama_memory_status_combine(ctx_attn->get_status(), ctx_recr->get_status())) {
}
bool llama_memory_hybrid_context::next() {
assert(status == LLAMA_MEMORY_STATUS_SUCCESS);
ctx_attn->next();
ctx_recr->next();
if (ctx_idx) ctx_idx->next();
if (++i_next >= ubatches.size()) {
return false;
}
return true;
}
bool llama_memory_hybrid_context::apply() {
assert(!llama_memory_status_is_fail(status));
bool res = true;
res = res & ctx_attn->apply();
res = res & ctx_recr->apply();
if (ctx_idx) res = res & ctx_idx->apply();
return res;
}
llama_memory_status llama_memory_hybrid_context::get_status() const {
return status;
}
const llama_ubatch & llama_memory_hybrid_context::get_ubatch() const {
assert(status == LLAMA_MEMORY_STATUS_SUCCESS);
return ubatches[i_next];
}
const llama_kv_cache_context * llama_memory_hybrid_context::get_attn() const {
return static_cast<const llama_kv_cache_context *>(ctx_attn.get());
}
const llama_memory_recurrent_context * llama_memory_hybrid_context::get_recr() const {
return static_cast<const llama_memory_recurrent_context *>(ctx_recr.get());
}
const llama_kv_cache_context * llama_memory_hybrid_context::get_idx() const {
return static_cast<const llama_kv_cache_context *>(ctx_idx.get());
}