diff --git a/examples/perplexity/perplexity.cpp b/examples/perplexity/perplexity.cpp index ea2c8026c..9498dd535 100644 --- a/examples/perplexity/perplexity.cpp +++ b/examples/perplexity/perplexity.cpp @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -444,6 +445,48 @@ static std::vector evaluate_tokens(llama_context * ctx, std::vector return result; } +static void hellaswag_compute_logprobs(const float * batch_logits, int n_vocab, std::vector& workers, + const std::vector>& eval_pairs, std::vector& eval_results) { + constexpr int k_token_chunk = 4; + if (eval_results.size() != eval_pairs.size()) { + eval_results.resize(eval_pairs.size()); + } + if (eval_pairs.empty()) return; + + size_t max_threads = std::min((eval_pairs.size() + k_token_chunk - 1)/k_token_chunk, workers.size()); + + std::atomic counter(0); + auto compute = [&counter, &eval_pairs, &eval_results, batch_logits, n_vocab] () { + float local_logprobs[k_token_chunk]; + while (true) { + size_t first = counter.fetch_add(k_token_chunk, std::memory_order_relaxed); + if (first >= eval_results.size()) break; + size_t last = std::min(first + k_token_chunk, eval_results.size()); + for (size_t i = first; i < last; ++i) { + auto logits = batch_logits + eval_pairs[i].first * n_vocab; + float max_logit = logits[0]; + for (int j = 1; j < n_vocab; ++j) { + max_logit = std::max(max_logit, logits[j]); + } + float sum_p = 0.f; + for (int j = 0; j < n_vocab; ++j) { + sum_p += expf(logits[j] - max_logit); + } + local_logprobs[i - first] = logits[eval_pairs[i].second] - max_logit - std::log(sum_p); + } + std::memcpy(eval_results.data() + first, local_logprobs, (last - first)*sizeof(float)); + } + }; + + for (size_t it = 0; it < max_threads; ++it) { + workers[it] = std::thread(compute); + } + for (size_t it = 0; it < max_threads; ++it) { + workers[it].join(); + } + +} + static void hellaswag_score(llama_context * ctx, const gpt_params & params) { // Calculates hellaswag score (acc_norm) from prompt // @@ -574,6 +617,10 @@ static void hellaswag_score(llama_context * ctx, const gpt_params & params) { std::vector tok_logits(n_vocab); std::vector batch_logits(n_ctx*n_vocab); + std::vector> eval_pairs; + std::vector eval_results; + std::vector workers(std::thread::hardware_concurrency()); + auto decode_helper = [&](llama_context * ctx, llama_batch & batch, int32_t n_batch) { for (int32_t i = 0; i < (int32_t) batch.n_tokens; i += n_batch) { const int32_t n_tokens = std::min(n_batch, (int32_t) (batch.n_tokens - i)); @@ -654,6 +701,24 @@ static void hellaswag_score(llama_context * ctx, const gpt_params & params) { return; } + // Compute log-probs in parallel + // First we collect all tasks + eval_pairs.clear(); + for (size_t i = i0; i < i1; ++i) { + auto & hs_cur = hs_data[i]; + size_t li = hs_cur.common_prefix; + for (int s = 0; s < 4; ++s) { + for (size_t j = hs_cur.common_prefix; j < hs_cur.seq_tokens[s].size() - 1; j++) { + eval_pairs.push_back(std::make_pair(hs_cur.i_batch + li++, hs_cur.seq_tokens[s][j + 1])); + } + ++li; + } + } + // Then we do the actual calculation + hellaswag_compute_logprobs(batch_logits.data(), n_vocab, workers, eval_pairs, eval_results); + + size_t ir = 0; + // compute the logprobs for each ending of the decoded tasks for (size_t i = i0; i < i1; ++i) { auto & hs_cur = hs_data[i]; @@ -662,26 +727,13 @@ static void hellaswag_score(llama_context * ctx, const gpt_params & params) { const auto first_probs = softmax(tok_logits); - size_t li = hs_cur.common_prefix; // logits index in the batch - for (int s = 0; s < 4; ++s) { hs_cur.ending_logprob_count[s] = 1; hs_cur.ending_logprob[s] = std::log(first_probs[hs_cur.seq_tokens[s][hs_cur.common_prefix]]); - - // Calculate the logprobs over the ending for (size_t j = hs_cur.common_prefix; j < hs_cur.seq_tokens[s].size() - 1; j++) { - std::memcpy(tok_logits.data(), batch_logits.data() + n_vocab*(hs_cur.i_batch + li++), n_vocab*sizeof(float)); - - const float prob = softmax(tok_logits)[hs_cur.seq_tokens[s][j + 1]]; - - hs_cur.ending_logprob[s] += std::log(prob); + hs_cur.ending_logprob[s] += eval_results[ir++]; hs_cur.ending_logprob_count[s]++; } - - // account that we skip the last token in the ending - ++li; - - // Calculate the mean token logprob for acc_norm hs_cur.ending_logprob[s] /= hs_cur.ending_logprob_count[s]; }