Re: [ECOS] slow connect in ftp_test

[Gary Thomas <gthomas at redhat dot com>]

A *lot* of things have been improved and/or fixed wrt the Viper
networking, now available from anonymous CVS.  Please update and
try this again and let us know if you still have problems.

On Tue, 2002-05-28 at 19:31, Paul Randall wrote:
> Hi all,
> 
> I recently tried running the ftp_test network test on my A&M Viper
> board.  I set up the viper to login to a FTP server which I ran on the
> host PC.  I am debugging with Insight over the serial port.
> 
> During the test, the ethernet interface is initialized ok, but when
> connect() is called, it takes about 60 seconds for the function to
> return.  The strange thing is, there is absolutely no traffic on the
> network until close to the end of the 60 seconds when the viper
> successfully connects to the host.  After a successful connection, the
> login process (username and password) also take a long time (about 20
> seconds).
> 
> I used Insight to trace into the connect() call and saw the 60 second
> delay happened in the bsd_connect() function of sockio.c:
> 
> static int bsd_connect   ( cyg_file *fp, const sockaddr *sa, socklen_t
> len )
> {
>     register struct socket *so;
>     struct mbuf *nam;
>     int error, s;
> 
>     so = (struct socket *)fp->f_data;
> 
>     if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING))
>         return (EALREADY);
> 
>     error = sockargs(&nam, (caddr_t)sa, len, MT_SONAME);
> 
>     if (error)
>         return (error);
> 
>     error = soconnect(so, nam);
>     if (error)
>         goto bad;
> 
>     if ((so->so_state & SS_NBIO) && (so->so_state & SS_ISCONNECTING)) {
>         m_freem(nam);
>         return (EINPROGRESS);
>     }
> 
>     s = splsoftnet();
>     while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
>         error = tsleep((caddr_t)&so->so_timeo, PSOCK | PCATCH,
>                        netcon, 0);
>         if (error)
>             break;
>     }
> 
>     if (error == 0) {
>         error = so->so_error;
>         so->so_error = 0;
>     }
> 
>     splx(s);
> 
> bad:
>     so->so_state &= ~SS_ISCONNECTING;
>     m_freem(nam);
> 
>     return error;
> }
> 
> The 60 second delay happens during the tsleep() call in the while loop
> after the soconnect() call.  The tsleep is waiting for a semaphore to be
> posted, but it is not posted until 60 seconds after the soconnect()
> call.
> 
> When the semaphore is finally posted it is posted from the tcp_input()
> function in tcp_input.c.  The call stack is:
> 
> Cyg_HardwareThread::thread_entry(Cyg_thread *)
> cyg_netint
> ipintr
> ipv4_input
> tcp_input
> soisconnected
> cyg_wakeup
> cyg_semaphore_post
> 
> Why does it take 60 seconds for this semaphore to be posted?
> 
> Paul Randall
> Delta Information Systems
> 
> 
> -- 
> Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
> and search the list archive: http://sources.redhat.com/ml/ecos-discuss



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