u8 compressed_ack
u8:2 dup_ack_counter
u8:1 tlp_retrans
-u8:1 tcp_usec_ts
+u8:1 tcp_usec_ts read_mostly read_mostly
u32 chrono_start read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)
u32[3] chrono_stat read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)
u8:2 chrono_type read_write - tcp_chrono_start/stop(tcp_write_xmit,tcp_cwnd_validate,tcp_send_syn_data)