perplexity: more statistics, added documentation (#6936)

* perplexity: more statistics, added documentation

* add LLaMA 3 8b scoreboard
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Johannes Gäßler 2024-04-30 23:36:27 +02:00 committed by GitHub
parent f364eb6fb5
commit a8f9b07631
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3 changed files with 291 additions and 59 deletions

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@ -216,17 +216,22 @@ static void process_logits(std::ostream& out, int n_vocab, const float * logits,
}
struct kl_divergence_result {
double sum_nll = 0;
double sum_nll2 = 0;
double sum_kld = 0;
double sum_kld2 = 0;
double sum_nll_diff = 0;
double sum_nll_diff2 = 0;
size_t n_same_top = 0;
size_t count = 0;
double sum_nll = 0.0;
double sum_nll2 = 0.0;
double sum_nll_base = 0.0;
double sum_nll_base2 = 0.0;
double sum_nll_nll_base = 0.0;
double sum_kld = 0.0;
double sum_kld2 = 0.0;
double sum_p_diff = 0.0;
double sum_p_diff2 = 0.0;
double sum_p_diff4 = 0.0;
float max_p_diff = 0.0f;
size_t n_same_top = 0.0;
size_t count = 0.0;
};
static double log_softmax(int n_vocab, const float * logits, const uint16_t * base_log_prob, int tok, kl_divergence_result & kld) {
static std::pair<double, float> log_softmax(int n_vocab, const float * logits, const uint16_t * base_log_prob, int tok, kl_divergence_result & kld) {
float max_logit = logits[0];
int imax = 0;
for (int i = 1; i < n_vocab; ++i) {
@ -244,12 +249,17 @@ static double log_softmax(int n_vocab, const float * logits, const uint16_t * ba
const float scale = d[0];
const float min_log_prob = d[1];
base_log_prob += 4;
float nll = max_logit + log_sum_exp - logits[tok];
const float nll = max_logit + log_sum_exp - logits[tok];
kld.sum_nll += nll;
kld.sum_nll2 += nll*nll;
nll += (scale*base_log_prob[tok] + min_log_prob);
kld.sum_nll_diff += nll;
kld.sum_nll_diff2 += nll*nll;
const float nll_base = -(scale*base_log_prob[tok] + min_log_prob);
kld.sum_nll_base += nll_base;
kld.sum_nll_base2 += nll_base*nll_base;
kld.sum_nll_nll_base += nll*nll_base;
max_logit += log_sum_exp;
double sum = 0;
int imax_base = -1;
@ -269,34 +279,50 @@ static double log_softmax(int n_vocab, const float * logits, const uint16_t * ba
kld.sum_kld2 += sum*sum;
++kld.count;
if (imax == imax_base) ++kld.n_same_top;
return sum;
const float p_base = expf(-nll_base);
const float p = expf(-nll);
const float p_diff = p - p_base;
kld.sum_p_diff += p_diff;
const double p_diff2 = p_diff*p_diff;
kld.sum_p_diff2 += p_diff2;
kld.sum_p_diff4 += p_diff2*p_diff2;
kld.max_p_diff = std::max(kld.max_p_diff, std::fabs(p_diff));
return std::make_pair(sum, p_diff);
}
static void process_logits(int n_vocab, const float * logits, const int * tokens, int n_token,
std::vector<std::thread> & workers, const std::vector<uint16_t> & base_log_probs, kl_divergence_result & kld,
float * kld_values) {
float * kld_values, float * p_diff_values) {
std::mutex mutex;
const int nv = 2*((n_vocab + 1)/2) + 4;
int counter = 0;
auto compute = [&mutex, &counter, &base_log_probs, &kld, n_vocab, logits, tokens, n_token, nv, kld_values] () {
auto compute = [&mutex, &counter, &base_log_probs, &kld, n_vocab, logits, tokens, n_token, nv, kld_values, p_diff_values] () {
kl_divergence_result local_kld;
while (true) {
std::unique_lock<std::mutex> lock(mutex);
int i = counter++;
if (i >= n_token) {
kld.sum_nll += local_kld.sum_nll;
kld.sum_nll2 += local_kld.sum_nll2;
kld.sum_kld += local_kld.sum_kld;
kld.sum_kld2 += local_kld.sum_kld2;
kld.sum_nll_diff += local_kld.sum_nll_diff;
kld.sum_nll_diff2 += local_kld.sum_nll_diff2;
kld.n_same_top += local_kld.n_same_top;
kld.count += local_kld.count;
kld.sum_nll += local_kld.sum_nll;
kld.sum_nll2 += local_kld.sum_nll2;
kld.sum_nll_base += local_kld.sum_nll_base;
kld.sum_nll_base2 += local_kld.sum_nll_base2;
kld.sum_nll_nll_base += local_kld.sum_nll_nll_base;
kld.sum_kld += local_kld.sum_kld;
kld.sum_kld2 += local_kld.sum_kld2;
kld.sum_p_diff += local_kld.sum_p_diff;
kld.sum_p_diff2 += local_kld.sum_p_diff2;
kld.sum_p_diff4 += local_kld.sum_p_diff4;
kld.n_same_top += local_kld.n_same_top;
kld.max_p_diff = std::max(kld.max_p_diff, local_kld.max_p_diff);
kld.count += local_kld.count;
break;
}
lock.unlock();
double v = log_softmax(n_vocab, logits + i*n_vocab, base_log_probs.data() + i*nv, tokens[i+1], local_kld);
kld_values[i] = (float)v;
std::pair<double, float> v = log_softmax(n_vocab, logits + i*n_vocab, base_log_probs.data() + i*nv, tokens[i+1], local_kld);
kld_values[i] = (float)v.first;
p_diff_values[i] = v.second;
}
};
for (auto & w : workers) {
@ -1711,7 +1737,8 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
GGML_ASSERT(llama_add_eos_token(llama_get_model(ctx)) != 1);
std::vector<uint16_t> log_probs_uint16(size_t(n_ctx - 1 - n_ctx/2) * nv);
std::vector<float> kld_values(size_t(n_ctx - 1 - n_ctx/2)*n_chunk);
std::vector<float> kld_values(size_t(n_ctx - 1 - n_ctx/2)*n_chunk);
std::vector<float> p_diff_values(size_t(n_ctx - 1 - n_ctx/2)*n_chunk);
std::vector<float> logits;
if (num_batches > 1) {
logits.reserve(n_ctx * n_vocab);
@ -1728,9 +1755,18 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
df = df > 0 && count > 10 ? sqrt(df/(count-1)) : 0.;
return std::make_pair(f, df);
};
auto covariance = [] (double suma, double sumb, double sumab, size_t count) {
if (count < 10) {
return 0.0;
}
double var = sumab/count - (suma/count)*(sumb/count);
var /= count - 1;
return var;
};
kl_divergence_result kld;
auto kld_ptr = kld_values.data();
auto kld_ptr = kld_values.data();
auto p_diff_ptr = p_diff_values.data();
for (int i = 0; i < n_chunk; ++i) {
const int start = i * n_ctx;
@ -1785,24 +1821,42 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
}
fprintf(stderr, "%.2f minutes\n", total_seconds / 60.0);
printf("\nchunk PPL ln(PPL(Q)/PPL(base)) KL-Divergence Same top\n");
printf("\nchunk PPL ln(PPL(Q)/PPL(base)) KL Divergence Δp RMS Same top p\n");
}
const int first = n_ctx/2;
const float * all_logits = num_batches > 1 ? logits.data() : llama_get_logits(ctx);
process_logits(n_vocab, all_logits + first*n_vocab, tokens.data() + start + first, n_ctx - 1 - first,
workers, log_probs_uint16, kld, kld_ptr);
kld_ptr += n_ctx - 1 - first;
workers, log_probs_uint16, kld, kld_ptr, p_diff_ptr);
p_diff_ptr += n_ctx - 1 - first;
kld_ptr += n_ctx - 1 - first;
auto ppl = mean_and_uncertainty(kld.sum_nll, kld.sum_nll2, kld.count);
auto log_ppl_ratio = mean_and_uncertainty(kld.sum_nll_diff, kld.sum_nll_diff2, kld.count);
auto kl_div = mean_and_uncertainty(kld.sum_kld, kld.sum_kld2, kld.count);
auto p_top = 1.*kld.n_same_top/kld.count;
auto d_p_top = sqrt(p_top*(1 - p_top)/(kld.count - 1));
printf("%4d", i+1);
printf("%4d %10.4lf %10.5lf ± %10.5f %10.5f ± %10.5lf %.5f ± %.5f\n", i+1, exp(ppl.first),
log_ppl_ratio.first, log_ppl_ratio.second, kl_div.first, kl_div.second,
p_top, d_p_top);
auto log_ppl = mean_and_uncertainty(kld.sum_nll, kld.sum_nll2, kld.count);
const double ppl_val = exp(log_ppl.first);
const double ppl_unc = ppl_val * log_ppl.second; // ppl_unc = sqrt( (dexp(x) / dx) ** 2 * log_ppl.second ** 2 )
printf(" %9.4lf ± %9.4lf", ppl_val, ppl_unc);
auto log_ppl_base = mean_and_uncertainty(kld.sum_nll_base, kld.sum_nll_base2, kld.count);
const double log_ppl_cov = covariance(kld.sum_nll, kld.sum_nll_base, kld.sum_nll_nll_base, kld.count);
const double log_ppl_ratio_val = log_ppl.first - log_ppl_base.first;
const double log_ppl_ratio_unc = sqrt(log_ppl.second*log_ppl.second + log_ppl_base.second*log_ppl_base.second - 2.0*log_ppl_cov);
printf(" %10.5lf ± %10.5lf", log_ppl_ratio_val, log_ppl_ratio_unc);
auto kl_div = mean_and_uncertainty(kld.sum_kld, kld.sum_kld2, kld.count);
printf(" %10.5lf ± %10.5lf", kl_div.first, kl_div.second);
auto p_diff_mse = mean_and_uncertainty(kld.sum_p_diff2, kld.sum_p_diff4, kld.count);
const double p_diff_rms_val = sqrt(p_diff_mse.first);
const double p_diff_rms_unc = 0.5/p_diff_rms_val * p_diff_mse.second;
printf(" %6.3lf ± %6.3lf %%", 100.0*p_diff_rms_val, 100.0*p_diff_rms_unc);
double p_top_val = 1.*kld.n_same_top/kld.count;
double p_top_unc = sqrt(p_top_val*(1 - p_top_val)/(kld.count - 1));
printf(" %6.3lf ± %6.3lf %%", 100.0*p_top_val, 100.0*p_top_unc);
printf("\n");
fflush(stdout);
@ -1813,31 +1867,97 @@ static void kl_divergence(llama_context * ctx, const gpt_params & params) {
if (kld.count < 100) return; // we do not wish to do statistics on so few values
std::sort(kld_values.begin(), kld_values.end());
std::sort(p_diff_values.begin(), p_diff_values.end());
printf("===== KL-divergence statistics\n");
printf("====== Perplexity statistics ======\n");
auto log_ppl = mean_and_uncertainty(kld.sum_nll, kld.sum_nll2, kld.count);
const double ppl_val = exp(log_ppl.first);
const double ppl_unc = ppl_val * log_ppl.second; // ppl_unc = sqrt( (dexp(x) / dx) ** 2 * log_ppl.second ** 2 )
printf("Mean PPL(Q) : %10.6lf ± %10.6lf\n", ppl_val, ppl_unc);
auto log_ppl_base = mean_and_uncertainty(kld.sum_nll_base, kld.sum_nll_base2, kld.count);
const double ppl_base_val = exp(log_ppl_base.first);
const double ppl_base_unc = ppl_base_val * log_ppl_base.second; // ppl_base_unc = sqrt( (dexp(x) / dx) ** 2 * log_ppl_base.second ** 2 )
printf("Mean PPL(base) : %10.6lf ± %10.6lf\n", ppl_base_val, ppl_base_unc);
const double log_ppl_cov = covariance(kld.sum_nll, kld.sum_nll_base, kld.sum_nll_nll_base, kld.count);
// printf("Cov(ln(PPL(Q)), ln(PPL(base))): %10.6lf\n", log_ppl_cov);
const double log_ppl_cor = log_ppl_cov / (log_ppl.second*log_ppl_base.second);
printf("Cor(ln(PPL(Q)), ln(PPL(base))): %6.2lf%%\n", 100.0*log_ppl_cor);
const double log_ppl_ratio_val = log_ppl.first - log_ppl_base.first;
const double log_ppl_ratio_unc = sqrt(log_ppl.second*log_ppl.second + log_ppl_base.second*log_ppl_base.second - 2.0*log_ppl_cov);
printf("Mean ln(PPL(Q)/PPL(base)) : %10.6lf ± %10.6lf\n", log_ppl_ratio_val, log_ppl_ratio_unc);
const double ppl_ratio_val = exp(log_ppl_ratio_val);
const double ppl_ratio_unc = ppl_ratio_val * log_ppl_ratio_unc; // ppl_ratio_unc = sqrt( (dexp(x) / dx) ** 2 * log_ppl_ratio.second ** 2 )
printf("Mean PPL(Q)/PPL(base) : %10.6lf ± %10.6lf\n", ppl_ratio_val, ppl_ratio_unc);
const double ppl_cov = ppl_val * ppl_base_val * log_ppl_cov;
const double ppl_diff_val = ppl_val - ppl_base_val;
const double ppl_diff_unc = sqrt(ppl_unc*ppl_unc + ppl_base_unc*ppl_base_unc - 2.0*ppl_cov);
printf("Mean PPL(Q)-PPL(base) : %10.6lf ± %10.6lf\n", ppl_diff_val, ppl_diff_unc);
printf("\n");
printf("====== KL divergence statistics ======\n");
auto kl_div = mean_and_uncertainty(kld.sum_kld, kld.sum_kld2, kld.count);
printf("Average: %10.6f ±%10.6lf\n", kl_div.first, kl_div.second);
printf("Mean KLD: %10.6lf ± %10.6lf\n", kl_div.first, kl_div.second);
auto kld_median = kld_values.size()%2 == 0 ? 0.5f*(kld_values[kld_values.size()/2] + kld_values[kld_values.size()/2-1])
: kld_values[kld_values.size()/2];
printf("Median : %10.6f\n", kld_median);
auto percentile = [&kld_values] (float fraction) {
if (fraction <= 0) return kld_values.front();
if (fraction >= 1) return kld_values.back();
float p = fraction*(kld_values.size() - 1);
auto percentile = [] (std::vector<float> values, float fraction) {
if (fraction <= 0) return values.front();
if (fraction >= 1) return values.back();
float p = fraction*(values.size() - 1);
size_t ip = size_t(p); p -= ip;
return (1 - p)*kld_values[ip] + p*kld_values[std::min(ip+1, kld_values.size()-1)];
return (1 - p)*values[ip] + p*values[std::min(ip+1, values.size()-1)];
};
printf("Maximum: %10.6f\n", kld_values.back());
printf("KLD_99 : %10.6f\n", percentile(0.99f));
printf("KLD_95 : %10.6f\n", percentile(0.95f));
printf("KLD_90 : %10.6f\n", percentile(0.90f));
printf("Maximum KLD: %10.6f\n", kld_values.back());
printf("99.9%% KLD: %10.6f\n", percentile(kld_values, 0.999f));
printf("99.0%% KLD: %10.6f\n", percentile(kld_values, 0.990f));
printf("99.0%% KLD: %10.6f\n", percentile(kld_values, 0.990f));
printf("Median KLD: %10.6f\n", kld_median);
printf("10.0%% KLD: %10.6f\n", percentile(kld_values, 0.100f));
printf(" 5.0%% KLD: %10.6f\n", percentile(kld_values, 0.050f));
printf(" 1.0%% KLD: %10.6f\n", percentile(kld_values, 0.010f));
printf("Minimum KLD: %10.6f\n", kld_values.front());
printf("Minimum: %10.6f\n", kld_values.front());
printf("KLD_01 : %10.6f\n", percentile(0.01f));
printf("KLD_05 : %10.6f\n", percentile(0.05f));
printf("KLD_10 : %10.6f\n", percentile(0.10f));
printf("\n");
printf("====== Token probability statistics ======\n");
auto p_diff = mean_and_uncertainty(kld.sum_p_diff, kld.sum_p_diff2, kld.count);
printf("Mean Δp: %6.3lf ± %5.3lf %%\n", 100.0*p_diff.first, 100.0*p_diff.second);
auto p_diff_median = p_diff_values.size()%2 == 0 ? 0.5f*(p_diff_values[p_diff_values.size()/2] + p_diff_values[p_diff_values.size()/2-1])
: p_diff_values[p_diff_values.size()/2];
printf("Maximum Δp: %6.3lf%%\n", 100.0*p_diff_values.back());
printf("99.9%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.999f));
printf("99.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.990f));
printf("95.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.950f));
printf("90.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.900f));
printf("75.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.750f));
printf("Median Δp: %6.3lf%%\n", 100.0*p_diff_median);
printf("25.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.250f));
printf("10.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.100f));
printf(" 5.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.050f));
printf(" 1.0%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.010f));
printf(" 0.1%% Δp: %6.3lf%%\n", 100.0*percentile(p_diff_values, 0.001f));
printf("Minimum Δp: %6.3lf%%\n", 100.0*p_diff_values.front());
auto p_diff_mse = mean_and_uncertainty(kld.sum_p_diff2, kld.sum_p_diff4, kld.count);
// printf("MSE Δp : %10.6lf ± %10.6lf\n", p_diff_mse.first, p_diff_mse.second);
const double p_diff_rms_val = sqrt(p_diff_mse.first);
const double p_diff_rms_unc = 0.5/p_diff_rms_val * p_diff_mse.second;
printf("RMS Δp : %6.3lf ± %5.3lf %%\n", 100.0*p_diff_rms_val, 100.0*p_diff_rms_unc);
const double same_top_p = 1.0*kld.n_same_top/kld.count;
printf("Same top p: %6.3lf ± %5.3lf %%\n", 100.0*same_top_p, 100.0*sqrt(same_top_p*(1.0 - same_top_p)/(kld.count - 1)));
}