Subject: Re: Hang when testing with AMD64 with Tg3

From: Stephen Hemminger <[email-masked]>
Date: Tue, 05 Oct 2004 10:06:15 -0700

On Tue, 2004-10-05 at 07:58 -0700, Nivedita Singhvi wrote:
> Stephen Hemminger wrote:
> > On Tue, 2004-10-05 at 02:15 +0200, Andi Kleen wrote:
> > 
> >>On Mon, Oct 04, 2004 at 05:11:11PM -0700, Stephen Hemminger wrote:
> >>
> >>>Doing simple iperf test on new opteron with tg3 against existing Xeon
> >>>system.  I am seeing something wierd, the connection hangs right away.
> >>>Is this a TSO bug.  
> >>>
> >>>Sender: BK latest (2.6.9-rc3) Tg3 (XX.YY.250.3)
> >>>Receiver: BK + netdev(jeffm) + dave's latest e100 (XX.YY.1.73)
> >>>
> >>>Both machines are directly connected with a netgear 100mbit switch.
> >>
> > 
> > IT ISN'T A NETWORK PROBLEM.  The problem is that iperf uses posix
> > pthread mutex's to sychronize and it looks like a futex bug.
> 
> might not be a futex bug - check to see if iperf does
> any writes, fflushes, etc, in a signal handler - i.e.
> that its signal handling is thread-safe. glibc now
> makes it a fatal bug..

It doesn't do I/O from signal handler, but the problem goes away when
not compiling with -O2.