请教LWIP，RAW API和sequential api内存占用上的不同？

eworker

是不是sequential方式要比raw方式多费很多内存？

eworker

是不是也没有多费多少内存？

eworker

sequential方式相比raw方式，多的数据结构：

struct netbuf {
struct pbuf *p, *ptr;//数据包相关部分
struct ip_addr *addr;//ip地址
u16_t port;//端口号
};

/** A netconn descriptor */
struct netconn {
  /** type of the netconn (TCP, UDP or RAW) */
  enum netconn_type type;
  /** current state of the netconn */
  enum netconn_state state;
  /** the lwIP internal protocol control block */
  union {
    struct ip_pcb  *ip;
    struct tcp_pcb *tcp;
    struct udp_pcb *udp;
    struct raw_pcb *raw;
  } pcb;
  /** the last error this netconn had */
  err_t err;
  /** sem that is used to synchroneously execute functions in the core context */
  sys_sem_t op_completed;
  /** mbox where received packets are stored until they are fetched
      by the netconn application thread (can grow quite big) */
  sys_mbox_t recvmbox;
  /** mbox where new connections are stored until processed
      by the application thread */
  sys_mbox_t acceptmbox;
  /** only used for socket layer */
  int socket;
#if LWIP_SO_RCVTIMEO
  /** timeout to wait for new data to be received
      (or connections to arrive for listening netconns) */
  int recv_timeout;
#endif /* LWIP_SO_RCVTIMEO */
#if LWIP_SO_RCVBUF
  /** maximum amount of bytes queued in recvmbox */
  int recv_bufsize;
#endif /* LWIP_SO_RCVBUF */
  u16_t recv_avail;
  /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
      this temporarily stores the message. */
  struct api_msg_msg *write_msg;
  /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
      this temporarily stores how much is already sent. */
  int write_offset;
#if LWIP_TCPIP_CORE_LOCKING
  /** TCP: when data passed to netconn_write doesn't fit into the send buffer,
      this temporarily stores whether to wake up the original application task
      if data couldn't be sent in the first try. */
  u8_t write_delayed;
#endif /* LWIP_TCPIP_CORE_LOCKING */
  /** A callback function that is informed about events for this netconn */
  netconn_callback callback;
};