[mythtv-users] mythbackend makes kernel throwing a wobbly

[Ben Lancaster]

Hi all,

My Mythbox has just started doing this:

-- snip from /var/log/messages --
Mar 24 00:56:13 benlancaster kernel: Unable to handle kernel paging  
request at ffff8100010fd4c0 RIP:
Mar 24 00:56:13 benlancaster kernel:  [<ffff8100010fd4c0>]
Mar 24 00:56:13 benlancaster kernel: PGD 8063 PUD 9063 PMD  
80000000010001e3 PTE 0
Mar 24 00:56:13 benlancaster kernel: Oops: 0011 [3] SMP
Mar 24 00:56:13 benlancaster kernel: last sysfs file: /block/sda/ 
removable
Mar 24 00:56:13 benlancaster kernel: CPU 1
Mar 24 00:56:13 benlancaster kernel: Modules linked in: appletalk  
nfsd exportfs lockd nfs_acl autofs4 sunrpc xfs dm_mirror dm_mod video  
sbs i2c_ec dock button battery asus_acpi backlight ac ipv6 lp  
parport_pc parport lirc_mceusb2(F)(U) lirc_imon(F)(U) lirc_dev(F)(U)  
mt2060(F)(U) dvb_usb_dib0700(F)(U) dib7000m(F)(U) dib7000p(F)(U)  
dvb_usb(F)(U) dvb_core(F)(U) dvb_pll(F)(U) dib3000mc(F)(U)  
dibx000_common(F)(U) snd_via82xx(F)(U) sg ehci_hcd gameport  
snd_ac97_codec(F)(U) ac97_bus(F)(U) snd_seq_dummy(F)(U) uhci_hcd  
snd_seq_oss(F)(U) snd_seq_midi_event(F)(U) nvidia(PF)(U) snd_seq(F) 
(U) snd_pcm_oss(F)(U) snd_mixer_oss(F)(U) snd_pcm(F)(U) snd_timer(F) 
(U) snd_page_alloc(F)(U) snd_mpu401_uart(F)(U) snd_rawmidi(F)(U)  
snd_seq_device(F)(U) 8139too i2c_viapro i2c_core 8139cp snd(F)(U) mii  
soundcore ide_cd cdrom pcspkr shpchp ext3 jbd sata_via libata sd_mod  
scsi_mod
Mar 24 00:56:13 benlancaster kernel: Pid: 2773, comm: mythbackend  
Tainted: PF     2.6.20-1.2300.fc5 #1
Mar 24 00:56:13 benlancaster kernel: RIP: 0010:[<ffff8100010fd4c0>]   
[<ffff8100010fd4c0>]
Mar 24 00:56:13 benlancaster kernel: RSP: 0018:ffff810028cd5d00   
EFLAGS: 00010286
Mar 24 00:56:13 benlancaster kernel: RAX: ffff8100010fd4c0 RBX:  
ffff810037cf9a80 RCX: 0000000000000195
Mar 24 00:56:13 benlancaster kernel: RDX: 0000000000000018 RSI:  
ffff81003fa0a680 RDI: ffff810037cf9a80
Mar 24 00:56:13 benlancaster kernel: RBP: ffff81003fa0a680 R08:  
0000000000000018 R09: 0000000000000008
Mar 24 00:56:13 benlancaster kernel: R10: 0000000000000000 R11:  
ffffffff804051ba R12: 00000000000000d0
Mar 24 00:56:13 benlancaster kernel: R13: ffff81003fa0a690 R14:  
0000000000000000 R15: 0000000000000000
Mar 24 00:56:13 benlancaster kernel: FS:  0000000000000000(0000)  
GS:ffff81003feb1b40(0000) knlGS:0000000000000000
Mar 24 00:56:13 benlancaster kernel: CS:  0010 DS: 0000 ES: 0000 CR0:  
000000008005003b
Mar 24 00:56:13 benlancaster kernel: CR2: ffff8100010fd4c0 CR3:  
000000002042b000 CR4: 00000000000006e0
Mar 24 00:56:13 benlancaster kernel: Process mythbackend (pid: 2773,  
threadinfo ffff810028cd4000, task ffff810026e94040)
Mar 24 00:56:13 benlancaster kernel: Stack:  ffffffff80223b10  
ffff81003fa0a680 000000000000023f 00000000000000d0
Mar 24 00:56:13 benlancaster kernel:  ffffffff802378f7  
ffff81003d22c480 ffff810026e94688 ffff81003fa0a680
Mar 24 00:56:13 benlancaster kernel:  ffff810026e94040  
0000000000000001 000000000000000f ffff810028cd5ef8
Mar 24 00:56:13 benlancaster kernel: Call Trace:
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff80223b10>] filp_close 
+0x37/0x65
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff802378f7>]  
put_files_struct+0x66/0xbf
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff80215203>] do_exit 
+0x29a/0x86f
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff802468b8>] cpuset_exit 
+0x0/0x6b
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff8022abff>]  
get_signal_to_deliver+0x437/0x466
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff80257b03>]  
do_notify_resume+0x9c/0x71c
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff80285931>]  
default_wake_function+0x0/0xe
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff8029c21b>] sys_futex 
+0x103/0x121
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff8025a1a7>]  
sysret_signal+0x1c/0x27
Mar 24 00:56:13 benlancaster kernel:  [<ffffffff8025a437>]  
ptregscall_common+0x67/0xb0
Mar 24 00:56:13 benlancaster kernel:
Mar 24 00:56:13 benlancaster kernel:
Mar 24 00:56:13 benlancaster kernel: Code: 00 00 00 00 00 08 00 00 01  
00 00 00 ff ff ff ff 00 00 00 00
Mar 24 00:56:13 benlancaster kernel: RIP  [<ffff8100010fd4c0>]
Mar 24 00:56:13 benlancaster kernel:  RSP <ffff810028cd5d00>
Mar 24 00:56:13 benlancaster kernel: CR2: ffff8100010fd4c0
Mar 24 00:56:13 benlancaster kernel:  <1>Fixing recursive fault but  
reboot is needed!

Here's what mythbackend is saying round the same time:

2007-03-24 00:53:43.278 TVRec(2): HW Tuner: 2->2
2007-03-24 00:54:20.896 EITScanner: Added 1106 EIT Events
2007-03-24 00:54:20.900 Reschedule requested for id -1.
2007-03-24 00:54:20.911 DVBChan(1) Error: Tune(): Setting Frontend  
tuning parameters failed.
                         eno: Inappropriate ioctl for device (25)
2007-03-24 00:54:20.915 DVBChan(1) Error: SetChannelByString(728):  
Tuning to frequency.
2007-03-24 00:54:20.916 TVRec(1) Error: Failed to set channel to 728.  
Reverting to kState_None
2007-03-24 00:54:20.917 EITScanner: Now looking for EIT data on  
multiplex of channel 728
2007-03-24 00:54:21.010 Scheduled 27 items in 0.1 = 0.07 match + 0.04  
place
2007-03-24 00:54:37.245 EITScanner: Added 843 EIT Events
2007-03-24 00:55:47.199 MainServer::HandleAnnounce Monitor
2007-03-24 00:55:47.206 adding: xxx as a client (events: 0)
2007-03-24 00:55:47.207 MainServer::HandleAnnounce Monitor
2007-03-24 00:55:47.208 adding: xxx as a client (events: 1)
2007-03-24 00:55:54.213 MainServer::HandleAnnounce Monitor
2007-03-24 00:55:54.216 adding: xxx as a client (events: 0)

I have no idea what it means or how to debug it, can anybody point me  
in the right direction?

My Kernel is 2.6.20-1.2300.fc5 #1 SMP Sun Mar 11 19:29:01 EDT 2007  
x86_64 x86_64 x86_64 GNU/Linux - I'm running latest MythTV RPMs from  
ATRPMS, on an Intel P4 with Nova-T 500

Thanks,

Ben