Network Bad Kernel Access

[Glenn.G.Hart at us.westinghouse.com]

I am having a problem with my network.  I am using a V4FX12 running linux
2.6.21 with the TEMAC.  I am running the PPC at 300 MHz and the TEMAC is
configured for DMA and DRE on the Xmit and the Recv.  I have tried varying
the FIFO depth and enabling/disabling the checksum offloading.  All produce
the error below when under heavy network traffic (specifically sending data
from the PPC).  Has anybody seen this?  It seems like I am overflowing some
memory, but I am not sure what/where to increase it.

Thanks,
Glenn



[  484.696738] Oops: kernel access of bad area, sig: 11 [#1]
[  484.761286] NIP: c00e1ef4 LR: c00cfec0 CTR: c00cfe34
[  484.820650] REGS: c0483b10 TRAP: 0300   Not tainted  (2.6.21)
[  484.889378] MSR: 00029030 <EE,ME,IR,DR>  CR: 93005999  XER: e0000000
[  484.965410] DAR: bb857caf, DSISR: 00000000
[  485.014365] TASK = c0648b60[129] 'rcS' THREAD: c0482000
[  485.074765] GPR00: c04fdfb8 c0483bc0 c0648b60 bb857c2b c04fd9a0 c0483bcc
04000000 ff107ac0
[  485.174747] GPR08: 0000000f c04fdfb8 c04d2478 00010001 00648d10 1003c2e0
00000000 00000001
[  485.274732] GPR16: 00000003 c0483ed8 00004fd8 000005b4 000005b4 00000000
00000000 0001679c
[  485.374716] GPR24: 7ff8b398 3002afe0 0000000f c04d2000 c04d23b8 c06bbe60
00000003 c04d2320
[  485.476784] NIP [c00e1ef4] kfree_skb+0x8/0x3c
[  485.528858] LR [c00cfec0] SgSendHandlerBH+0x8c/0x1cc
[  485.588223] Call Trace:
[  485.617389] [c0483bc0] [c00cfec0] SgSendHandlerBH+0x8c/0x1cc
(unreliable)
[  485.698628] [c0483bf0] [c0019218] tasklet_action+0x90/0xd4
[  485.764241] [c0483c00] [c0018ebc] __do_softirq+0x64/0xd0
[  485.827772] [c0483c20] [c00064a8] do_softirq+0x40/0x58
[  485.889221] [c0483c30] [c0018f74] irq_exit+0x38/0x48
[  485.948586] [c0483c40] [c0006450] do_IRQ+0x88/0xa0
[  486.005868] [c0483c50] [c00032d8] ret_from_except+0x0/0x18
[  486.071483] [c0483d10] [c0483d00] 0xc0483d00
[  486.122516] [c0483d20] [c00e17d4] __alloc_skb+0x48/0x11c
[  486.186048] [c0483d40] [c0109218] tcp_sendmsg+0x1ac/0xc40
[  486.250621] [c0483db0] [c0126b58] inet_sendmsg+0x60/0x74
[  486.314152] [c0483dd0] [c00dcf34] sock_aio_write+0xe0/0xfc
[  486.379765] [c0483e30] [c0050910] do_sync_write+0xb8/0x10c
[  486.445381] [c0483ef0] [c0050a40] vfs_write+0xdc/0x10c
[  486.506829] [c0483f10] [c0050b48] sys_write+0x4c/0x8c
[  486.567236] [c0483f40] [c0002c90] ret_from_syscall+0x0/0x3c
[  486.633888] Instruction dump:
[  486.669300] 0f000000 7fe3fb78 7d6803a6 4e800021 80010014 7fe3fb78
7c0803a6 bbc10008
[  486.761992] 38210010 4bfffe78 2c030000 4d820020 <80030084> 39230084
2f800001 409e0008
[  486.858162] Kernel panic - not syncing: Aiee, killing interrupt handler!
[  486.938382] Rebooting in 180 seconds..