altera TSE + nios2 linu为何实际速度如此慢！！！

fbc99

我的板子是Cyclone III FPGA Development Kit (3C120 board)，参考http://rocketboards.org/foswiki/ ... ManualForCycloneIII，
nios2 linux能够启动，altera TSE工作正常，的确是工作在1000M full duplex模式，但是和PC Windows之间做测试时，发现网卡的速度奇慢无比，UDP的速度只有40～50Mbps。


有人能指点一下为何速度如此慢？


nios2 linux中我做udp测试的函数如下：


int udp_handshake( )
{
int ipLen,i,iRet;
unsigned short udp_marks[8];
int net_error;

net_error=0;

printf("now to handshake by udp\n");


m_udp_socket=socket(AF_INET,SOCK_DGRAM,0);

memset(&addrin,0, sizeof(struct sockaddr_in) );
addrin.sin_family=AF_INET;
addrin.sin_port = htons(3500);
memset(&addrin.sin_zero,0,8);

if(bind(m_udp_socket,(struct sockaddr *)&addrin, sizeof(struct sockaddr_in))) //int bind (int SOCKET, struct sockaddr *ADDR, socklen_t LENGTH)
{
printf("can't creat net interface.......\r\n");
close(m_udp_socket);
return 0;
}

ipLen=sizeof(struct sockaddr_in);
for(i=0;i<8;i++)
{
udp_marks=0;
}
iRet=recvfrom(m_udp_socket, (char * )udp_marks, 16, 0,(struct sockaddr *)&addrin, &ipLen); //first recv mark by blocking mode


printf("pc IP:%s port:%d\r\n",inet_ntoa(addrin.sin_addr),ntohs(addr in.sin_port) );


addrin.sin_port=htons(3500); ipLen=sizeof(struct sockaddr_in);

//test altera TSE speed with udp sending loop, data_length is from 1 to 32, so 1K to 32K data is sent by one sendto
for (i=0;i<send_loop;i++)
{
iRet=sendto(m_udp_socket, (char *)pData_buff, data_length*1024,0,(struct sockaddr *)&addrin,ipLen); //second send back handshake

if (iRet==-1)
{
net_error=1;
}
}


shutdown(m_udp_socket,2);        close(m_udp_socket);

return 1;

}