bizarre nfe(4) problem

[Pyun YongHyeon]

On Sat, Aug 11, 2007 at 06:22:22PM +0900, To Don Lewis wrote:
 > On Fri, Aug 10, 2007 at 10:42:19PM -0700, Don Lewis wrote:
 >  > I've a rather strange nfe(4) problem that appears to be repeatable.  I
 >  > recently started running -CURRENT on a older socket 754 motherboard with
 >  > the nForce3 chipset.  Initially, I was running an SMP kernel, but I had
 >  > problems with sporadic "nfe0: watchdog timeout (missed Tx interrupts) --
 >  > recovering" problems that would intermittently cause the system to lose
 >  > network connectivity which it would recover from.  The kernel was very
 >  > similar to GENERIC, with just the addition of "options DEBUG_VFS_LOCKS"
 >  > and the replacement of atapicd with atapicam.
 >  > 
 >  > The nfe0 problem totally went away when I removed "options SMP" and
 >  > "device apic" from the kernel configuration, except under the following
 >  > very specific circumstances:
 >  > 
 >  > 	A vncserver session using the GNOME desktop was started on the
 >  > 	system.
 >  > 	
 >  > 	There was no keyboard or mouse activity on the console for an
 >  > 	extended period of time, allowing the GNOME screen saver to kick
 >  > 	in and lock the screen.
 >  > 
 >  > The system would run fine in this state for many hours, and would accept
 >  > incoming SMTP connections, etc.
 >  > 
 >  > 	A remote vncclient makes a connection to the vncserver session
 >  > 	and the password was entired on the client.
 >  > 
 >  > At this point the nfe0 interface would appear to go deaf.  This might
 >  > happen before or slightly after the password dialog box appeared for the
 >  > vnc session.  For a short while, the system would be able to transmit
 >  > TCP packets, ntp queries, etc., but it would not respond to any incoming
 >  > packets (ping, TCP connection requests, etc.). Eventually, the ARP cache
 >  > would time out and the only packets being transmitted would be ARP
 >  > requests and the occasional UDP broadcast from the samba server running
 >  > on the machine.
 >  > 
 >  > Pressing any key on the (PS/2) keyboard would instantly bring the
 >  > network interface back to life.  Examination of /var/log/messages showed
 >  > lots of "nfe0: watchdog timeout" messages for the entire time that nfe0
 >  > was not listening to the network.
 >  > 
 >  > I've had this problem happen twice.  Both times were after an extended
 >  > period of console inactivity.   An incoming vnc connection is not
 >  > sufficient to trigger the problem if the console was recently active,
 >  > and even waiting for the GNOME screensaver to put the monitor in DPMS
 >  > power save mode before initiating the vnc connection does not appear to
 >  > be sufficient to trigger the problem.
 >  > 
 >  > I believe that nfe0 was sharing an interrupt with one of the USB ports
 >  > when the kernel was compiled with "device apic", but it is not sharing
 >  > an interrupt without "device apic".
 >  > 
 >  > Any thoughts on how to debug this problem?
 >  > 
 >  > 
 >  > # vmstat -i
 >  > interrupt                          total       rate
 >  > irq0: clk                       41903449       1000
 >  > irq1: atkbd0                       39034          0
 >  > irq3: ohci0                            5          0
 >  > irq7: ppc0                             2          0
 >  > irq8: rtc                        5362802        127
 >  > irq9: ohci1 ahc0+                1963559         46
 >  > irq10: nfe0+                      225593          5
 >               ^^
 > You have nfe0+ which indicates vmstat had run out of room to
 > display somthing. I'm not sure but it's still sharing interrupt
 > with other device?

It seems the interrupt is shared with atapci1.

 > 
 >  > irq11: drm0                      2511908         59
 >  > irq12: psm0                       332931          7
 >  > irq14: ata0                           48          0
 >  > Total                           52339331       1249
 >  > 
 > 
 > -- 
 > Regards,
 > Pyun YongHyeon

-- 
Regards,
Pyun YongHyeon