server : take into account speculative limits

ggml-ci
This commit is contained in:
Georgi Gerganov 2024-12-04 10:44:48 +02:00
parent a5a915b51e
commit b436edaad9
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GPG Key ID: 449E073F9DC10735

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@ -921,6 +921,8 @@ struct server_context {
slot.params.speculative.p_min = json_value(data, "speculative.p_min", defaults.speculative.p_min);
slot.params.speculative.n_min = std::min(slot.params.speculative.n_max, slot.params.speculative.n_min);
slot.params.speculative.n_min = std::max(slot.params.speculative.n_min, 2);
slot.params.speculative.n_max = std::max(slot.params.speculative.n_max, 0);
if (slot.params.sampling.dry_base < 1.0f) {
slot.params.sampling.dry_base = defaults.sampling.dry_base;
@ -2322,10 +2324,29 @@ struct server_context {
continue;
}
// determine the max draft that fits the current slot state
int n_draft_max = slot.params.speculative.n_max;
// note: n_past is not yet increased for the `id` token sampled above
// also, need to leave space for 1 extra token to allow context shifts
n_draft_max = std::min(n_draft_max, slot.n_ctx - slot.n_past - 2);
if (slot.n_remaining > 0) {
n_draft_max = std::min(n_draft_max, slot.n_remaining - 1);
}
SLT_DBG(slot, "max possible draft: %d\n", n_draft_max);
if (n_draft_max < slot.params.speculative.n_min) {
SLT_DBG(slot, "the max possible draft is too small: %d < %d - skipping speculative decoding\n", n_draft_max, slot.params.speculative.n_min);
continue;
}
llama_token id = slot.sampled;
struct common_speculative_params params_spec;
params_spec.n_draft = std::min(slot.params.speculative.n_max, slot.n_ctx - slot.n_past - 1);
params_spec.n_draft = n_draft_max;
params_spec.n_reuse = llama_n_ctx(slot.ctx_dft) - slot.params.speculative.n_max;
params_spec.p_min = slot.params.speculative.p_min;
@ -2333,6 +2354,8 @@ struct server_context {
// ignore small drafts
if (slot.params.speculative.n_min > (int) draft.size()) {
SLT_DBG(slot, "ignoring small draft: %d < %d\n", (int) draft.size(), slot.params.speculative.n_min);
continue;
}
@ -2344,6 +2367,8 @@ struct server_context {
common_batch_add(slot.batch_spec, draft[i], slot.n_past + 1 + i, { slot.id }, true);
}
SLT_DBG(slot, "decoding speculative batch, size = %d\n", slot.batch_spec.n_tokens);
llama_decode(ctx, slot.batch_spec);
// the accepted tokens from the speculation
@ -2372,7 +2397,7 @@ struct server_context {
}
}
SRV_DBG("accepted %d/%d draft tokens\n", (int) ids.size() - 1, (int) draft.size());
SLT_DBG(slot, "accepted %d/%d draft tokens, new n_past = %d\n", (int) ids.size() - 1, (int) draft.size(), slot.n_past);
}
}