Add elapsed_s column to log.csv for structured metrics consumers

Forge Studio (the GUI companion) tails log.csv as its metrics channel;
wall-clock elapsed enables its time-axis mode and honest ETA math.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

simon-pierre boucher committed 5 days ago (Aug 5, 2026) parent 2e570b0

Showing 1 changed file with +6 and −3

modified src/train/trainer.cpp +6 −3

		`@@ -103,7 +103,8 @@ void Trainer::train(const std::string& resume_from) {`
103	103	FILE* csv = std::fopen((out_dir_ + "/log.csv").c_str(),
104	104	start_step > 0 ? "ab" : "wb");
105	105	if (csv && start_step == 0)
106		− std::fprintf(csv, "step,loss,lr,grad_norm,tokens_per_sec,val_loss\n");
	106	+ std::fprintf(csv, "step,loss,lr,grad_norm,tokens_per_sec,val_loss,elapsed_s\n");
	107	+ const auto run_t0 = std::chrono::steady_clock::now();
107	108
108	109	const int64_t min_lr_steps = tc.max_steps;
109	110	const float min_lr = tc.lr * tc.min_lr_ratio;
		`@@ -168,9 +169,11 @@ void Trainer::train(const std::string& resume_from) {`
168	169	std::fflush(stdout);
169	170	}
170	171	if (csv) {
171		− std::fprintf(csv, "%lld,%.6f,%.6e,%.6f,%.1f,%.6f\n",
	172	+ const double elapsed =
	173	+ std::chrono::duration<double>(t1 - run_t0).count();
	174	+ std::fprintf(csv, "%lld,%.6f,%.6e,%.6f,%.1f,%.6f,%.3f\n",
172	175	static_cast<long long>(step), loss_val, double(lr),
173		− double(grad_norm), tps, double(val));
	176	+ double(grad_norm), tps, double(val), elapsed);
174	177	std::fflush(csv);
175	178	}
176	179
177	180