ckpt_epoch_1_step_500/eval_results.json

{
    "eval_gen_len": 12.159915,
    "eval_loss": 2.153403,
    "eval_rouge1": 38.644711,
    "eval_rouge2": 13.35726,
    "eval_rougeL": 34.996203,
    "eval_rougeLsum": 35.002078
}