Improve turbomind's prefix cache #3835
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lvhan028
requested review from
irexyc and
lzhangzz
and removed request for
irexyc
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lzhangzz
approved these changes
Aug 19, 2025
irexyc
reviewed
Aug 22, 2025
| @@ -80,6 +83,7 @@ def main(model_path, backend, **kwargs): | |||
| try: | |||
| for resp in resps: | |||
| print(resp.text, end='', flush=True) | |||
| pass | |||
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| const int output_len = state_->h_context_length[index]; | ||
| auto& seq = *state_->sequences[index]; | ||
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| // Update token IDs | ||
| seq.tokens.resize(output_len); | ||
| // Update token IDs | ||
| seq.tokens.resize(output_len); | ||
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| // output_ids is updated & synced in `Finish` | ||
| const auto output_ids = state_->requests[index]->output_ids.data(); | ||
| std::copy_n(output_ids, output_len, seq.tokens.data()); | ||
| // output_ids is updated & synced in `Finish` | ||
| const auto output_ids = state_->requests[index]->output_ids.data(); | ||
| std::copy_n(output_ids, output_len, seq.tokens.data()); | ||
| // Cache the generated tokens of the sequence | ||
| if (!force_stop) { | ||
| sequence_manager_->CacheGeneration(seq); | ||
| } | ||
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| // Save random state in host memory | ||
| seq.random_state.resize(sizeof(curandState_t)); | ||
| // This async copy must be synchronized by the caller | ||
| core::Copy((curandState_t*)state_->curand_state.data() + index, 1, (curandState_t*)seq.random_state.data()); | ||
| // Save random state in host memory | ||
| seq.random_state.resize(sizeof(curandState_t)); | ||
| // This async copy must be synchronized by the caller | ||
| core::Copy((curandState_t*)state_->curand_state.data() + index, 1, (curandState_t*)seq.random_state.data()); | ||
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| // Set unlock flag for corresponding blocks, will be unlocked in the next `Materialize()` | ||
| sequence_manager_->UpdateAndSetUnlock(seq); | ||
| // Set unlock flag for corresponding blocks, will be unlocked in the next `Materialize()` | ||
| sequence_manager_->UpdateAndSetUnlock(seq); | ||
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| if (state_->requests[index]->session.end_flag) { | ||
| // Sequence is ending this round | ||
| FT_CHECK(sequence_manager_->Erase(state_->requests[index]->id)); |
There was a problem hiding this comment.
I think we should refer to previous code here. With state_->requests[index]->session.end_flag=True, there is no need to output token id and save random_state.
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| if (param_.enable_prefix_caching && !r->session.start_flag) { | ||
| // Prefix caching is incompatible with interactive mode | ||
| TM_LOG_ERROR("Skip inconsistent %s request for ID %lu", type, r->id); | ||
| r->ec = Request::kInconsistency; | ||
| } |
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I think we could check session.step == 0 here, so that we don't need to modify line 233-236, 262 and maybe 1018.
| const int history_len = state_->sequences[i]->tokens.size(); | ||
| const int cache_len = state_->sequences[i]->cache_len; | ||
| const int history_len = | ||
| !param_.enable_prefix_caching ? state_->sequences[i]->tokens.size() : state_->requests[i]->session.step; |
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I am confused about the setting state_->requests[i]->session.step
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