On Thu, Mar 29, 2007 at 08:55:25PM +0200, Mariusz Kozłowski wrote: > > > > > > > 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
Yep, that's a known problem with this driver: http://lkml.org/lkml/2007/2/17/222 This was a known theoretical problem with netconsole from the start but I'm actually not aware of any other drivers that have run into it. My preferred fix is to create a netconsole_disable/enable API for drivers that have this sort of reentrancy problem. -- Mathematics is the supreme nostalgia of our time. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
