vbatts/llama.cpp
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mamba : support llama_kv_cache_seq_cp copy chains

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* mamba : support shifting and dividing the kv cache pos
This commit is contained in:
Francis Couture-Harpin 2024-02-25 09:51:49 -05:00
parent 9473ec2147
commit 3dcf79824d
1 changed files with 34 additions and 35 deletions
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65
llama.cpp
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@ -2184,18 +2184,17 @@ static bool llama_kv_cache_find_slot(
} }
// Assuming the tokens are in-order // Assuming the tokens are in-order
if (batch.pos[i] != cache.cells[seq_id].pos + 1) { if (batch.pos[i] != cache.cells[seq_id].pos + 1) {
// What should happen when the pos backtracks? // What should happen when the pos backtracks or skips a value?
// Clearing the state mid-batch would require special-casing which isn't done. // Clearing the state mid-batch would require special-casing which isn't done.
LLAMA_LOG_ERROR("%s: non-consecutive token position %d after %d for sequence %d\n", LLAMA_LOG_WARN("%s: non-consecutive token position %d after %d for sequence %d\n",
__func__, batch.pos[i], cache.cells[seq_id].pos, seq_id); __func__, batch.pos[i], cache.cells[seq_id].pos, seq_id);
return false;
} }
cache.cells[seq_id].pos = batch.pos[i]; cache.cells[seq_id].pos = batch.pos[i];
// NOTE: seq_ids are not inserted here, because they are handled when the graph is built. // NOTE: seq_ids are not inserted here; they are handled when the input tensors are set
} else { } else {
// too big seq_id // too big seq_id
// TODO: would it be possible to resize the KV cache size instead? // TODO: would it be possible to resize the KV cache size instead?
LLAMA_LOG_ERROR("%s: seq_id=%d >= kv_size=%d\n", __func__, seq_id, cache.size); LLAMA_LOG_ERROR("%s: seq_id=%d >= kv_size=%d Try using a bigger --parallel value\n", __func__, seq_id, cache.size);
return false; return false;
} }
} }
@ -2327,23 +2326,25 @@ static void llama_kv_cache_seq_cp(
if (cache.unlimited) { if (cache.unlimited) {
if ((uint32_t) seq_id_dst < cache.size && (uint32_t) seq_id_src < cache.size) { if ((uint32_t) seq_id_dst < cache.size && (uint32_t) seq_id_src < cache.size) {
// intent to "copy from" (does not support copy chains) seq_id_src = cache.cells[seq_id_src].delta;
GGML_ASSERT((uint32_t) seq_id_src < cache.size);
// intent to "copy from"
// supports copy chains thanks to taking the source of the source
cache.cells[seq_id_dst].delta = seq_id_src; cache.cells[seq_id_dst].delta = seq_id_src;
// NOTE: a sequence can't have multiple sources, but can have multiple destinations.
// For compatibility with the other KV cache API functions, // prevent the destination from getting cleared if the source is not empty
// the seq_id(s) of a cell suggests an intent to "copy to" those id(s), if (cache.cells[seq_id_src].has_seq_id(seq_id_src)) {
// so that when a sequence is copied, it can initially be found from the source cell.
cache.cells[seq_id_src].seq_id.insert(seq_id_dst);
// prevent the destination from getting cleared
cache.cells[seq_id_dst].seq_id.insert(seq_id_dst); cache.cells[seq_id_dst].seq_id.insert(seq_id_dst);
}
// repurposed as a "need copy" flag // repurposed as a "need copy" flag
// (shifting can't be done anyway for this kind of KV cache) // (shifting can't be done anyway for this kind of KV cache)
cache.has_shift = seq_id_src != seq_id_dst; cache.has_shift = true;
// NOTE: this is not correct for sequence swaps (which aren't a thing in the KV cache API yet)
cache.cells[seq_id_dst].pos = cache.cells[seq_id_src].pos; cache.cells[seq_id_dst].pos = cache.cells[seq_id_src].pos;
} }
return; return;
} }
// otherwise, this is the KV cache of a Transformer-like model
cache.head = 0; cache.head = 0;
@ -2385,7 +2386,14 @@ static void llama_kv_cache_seq_add(
if (p1 < 0) p1 = std::numeric_limits<llama_pos>::max(); if (p1 < 0) p1 = std::numeric_limits<llama_pos>::max();
if (cache.unlimited) { if (cache.unlimited) {
GGML_ASSERT(false); // not supported // for Mamba-like models, only the pos needs to be shifted
if (0 <= seq_id && seq_id < (int64_t) cache.size) {
llama_kv_cell & cell = cache.cells[seq_id];
if (cell.has_seq_id(seq_id) && p0 <= cell.pos && cell.pos < p1) {
cell.pos += delta;
}
}
return;
} }
for (uint32_t i = 0; i < cache.size; ++i) { for (uint32_t i = 0; i < cache.size; ++i) {
@ -2422,7 +2430,14 @@ static void llama_kv_cache_seq_div(
if (p1 < 0) p1 = std::numeric_limits<llama_pos>::max(); if (p1 < 0) p1 = std::numeric_limits<llama_pos>::max();
if (cache.unlimited) { if (cache.unlimited) {
GGML_ASSERT(false); // not supported // for Mamba-like models, only the pos needs to be changed
if (0 <= seq_id && seq_id < (int64_t) cache.size) {
llama_kv_cell & cell = cache.cells[seq_id];
if (cell.has_seq_id(seq_id) && p0 <= cell.pos && cell.pos < p1) {
cell.pos /= d;
}
}
return;
} }
for (uint32_t i = 0; i < cache.size; ++i) { for (uint32_t i = 0; i < cache.size; ++i) {
@ -8435,7 +8450,6 @@ static void llama_set_inputs(llama_context & lctx, const llama_batch & batch) {
} }
if (kv_self.unlimited) { if (kv_self.unlimited) {
const int64_t kv_size = kv_self.size;
const int64_t n_kv = kv_self.n; const int64_t n_kv = kv_self.n;
{ {
@ -8451,7 +8465,7 @@ static void llama_set_inputs(llama_context & lctx, const llama_batch & batch) {
data[i] = (float) has_self_seq; data[i] = (float) has_self_seq;
// ensure current sequences will be kept // ensure current sequences will be kept
if (!has_self_seq) { if (!has_self_seq && kv_cell.pos >= 0) {
kv_cell.seq_id.insert(seq_id); kv_cell.seq_id.insert(seq_id);
} }
} }
@ -8480,21 +8494,6 @@ static void llama_set_inputs(llama_context & lctx, const llama_batch & batch) {
} }
} }
} }
// remove extraneous seq_ids when state copies are made
{
for (int i = 0; i < kv_size; ++i) {
llama_kv_cell & kv_cell = lctx.kv_self.cells[i];
uint32_t n_seqs = kv_cell.seq_id.size();
bool has_self_seq = kv_cell.has_seq_id(i);
if (has_self_seq && n_seqs > 1) {
kv_cell.seq_id.clear();
kv_cell.seq_id.insert(i);
} else if (!has_self_seq && n_seqs > 0) {
kv_cell.seq_id.clear();
}
}
}
} }
} }