Re: 2.6.21-rc5-mm1

Mariusz Kozłowski
2007-03-29T18:43:07Z

> > > > > > I run 2.6.21-rc4-mm1 with no hangs for a week.
> > > > > > Then when 2.6.21-rc5-mm1 showed up so I switched to it. Unfortunately
> > > > > > today my laptop hunged twice in a similar way as described here:
> > > > > >
> > > > > > http://www.ussg.iu.edu/hypermail/linux/kernel/0703.0/index.html#1165
> > > > >
> > > > > It's not good that we went backwards between those two releases.
> > > > >
> > > > > > The difference is that it happened when I closed the lid in my laptop.
> > > > > > When reopend it the box was frozen (ACPI?). Again disk I/O was dead
> > > > > > so nothing was found in syslog.
> > > > >
> > > > > Adrian, does this look like any of the bugs whcih you're monitoring?
> > > > >...
> > > >
> > > > Is it also present in 2.6.21-rc5?
> > >
> > > Don't know. I usualy test -mm series. Will test tommorow and let you know
> > > after some reasonable uptime.
> > >
> > > > Is it also present with CONFIG_NO_HZ=n?
> > >
> > > Don't know. Did not try recently. Will let you know.
> > >
> > > It takes time as these hangs are not easy to trigger. With 2.6.21-rc2-mm1
> > > it was easy -> push the system and watch it die in minutes. With
> > > 2.6.21-rc5-mm1 it takes hours (3 hangs in ~15 hours) and not sure how to
> > > trigger it. It just happens from time to time.
> >
> > Ok. CONGIG_NO_HZ=n and uptime ~12 hours, netconsole loaded, and no hangs
> > ... until I moved my laptop. The same scenario happened yesterday during the
> > last hang. I started playing and repeating some steps which I naturally do when
> > I move my laptop.
> >
> > An hour later I came to this -> steps to hang 2.6.21-rc5-mm1 on my laptop:
> > 1. boot the system and login as root
> > 2. load netconsole (insmod netconole.ko netconsole=blah... blah...)
> > 3. unplug the cable (link goes down)
> > 4. system is frozen until forced to reboot
> >
> > This is verified and repeatable _every_ single time I tried. Unfortunately
> > the last thing seen on the screen before system is frozen is 'eth0: link down'.
> > So my guess is that when hunting for hangs I found something else that can hang
> > my laptop (netconsole that is).
>
> Which NIC do you have? Odds are that the driver is doing that printk
> while holding a driver-internal spinlock that causes it to deadlock
> when netpoll tries to send that message out.

8139too was in use. This is from lspci:

00:12.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
Subsystem: Sony Corporation Unknown device 8158
Flags: bus master, medium devsel, latency 64, IRQ 11
I/O ports at 9c00 [size=256]
Memory at f0404c00 (32-bit, non-prefetchable) [size=512]
Capabilities: [50] Power Management version 2

> BTW, I guess David Miller is the defacto netpoll maintainer these days
> as most of the patches to it in the past year or two were not even
> cc:ed to me.

Ok sorry. I was looking at Documentation/networking/netconsole.txt -> 'Please send bug
reports to Matt Mackall <mpm@selenic.com>'. David added to CC.

Thanks.