2.4.4/2.4.5-pre2 process semi stuck in n_tty.c:write_chan

2.4.4/2.4.5-pre2 process semi stuck in n_tty.c:write_chan

[Andreas Schultz]

Hi,

I just installed a new system using 2.4.4 and later tried 2.4.5pre2 and 
2.4.4ac6 and ac9. All versions show the same behaivior.

When doing a "cat /var/log/messages", the output slows down after the 
first 30 lines and comes to an almost complete stop, with a few lines 
showing up every 10sec or so.

A "ps -eo pid,tt,user,fname,tmout,f,nwchan,wchan" shows the process 
sitting in write_chan in n_tty.c line 1198.

I realize that this information is probably not enough to find out whats 
going on, could you please advise me on what further information is 
needed and how to get it.

Thanks

    Andreas
---- snip ----
                 if (!nr)
                         break;
                 if (file->f_flags & O_NONBLOCK) {
                         retval = -EAGAIN;
                         break;
                 }
here ===>       schedule();
         }
break_out:
         current->state = TASK_RUNNING;
         remove_wait_queue(&tty->write_wait, &wait);
         return (b - buf) ? b - buf : retval;
}
---- snip ----