/* if gap increased - we should increase flushing, and otherwise */
                        if (lsn_gap_grow > 0) {
                                n_flush_diff_dbl = (double) n_flush_dbl * ( lsn_gap ) * srv_grow_flush_pct / max_age_gap / 1000;
                        } else {
                                n_flush_diff_dbl = - (double) n_flush_dbl * ( log_sys->max_modified_age_async -  lsn_gap ) * srv_grow_flush_pct / max_age_gap / 1000;
                        }