This is a uniprocessor AMD64 system running software RAID-5 and RAID-10 over multiple PCIe SiI3132 SATA controllers. The hardware has been very stable for a long time, but has been acting up of late since I upgraded to 2.6.20.3. ECC memory should preclude the possibility of bit-flip errors. Kernel 2.6.20.3 + linuxpps patches (confined to drivers/serial, and not actually in use as I stole the serial port for a console). It takes half a day to reproduce the problem, so bisecting would be painful. BackupPC_dump mostly writes to a large (1.7 TB) ext3 RAID5 partition. Here are two oopes, a few minutes (16:31, to be precise) apart. Unusually, it oopsed twice *without* locking up the system.. Usually, I see this followed by an error from drivers/input/keyboard/atkbd.c: printk(KERN_WARNING "atkbd.c: Spurious %s on %s. " "Some program might be trying access hardware directly.\n", emitted at 1 Hz with the keyboard LEDs flashing and the system unresponsive to keyboard or pings. (I think it was spurious ACK on serio/input0, but my memory may be faulty.) If anyone has any suggestions, they'd be gratefully received. Unable to handle kernel NULL pointer dereference at 0000000000000098 RIP: [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x68 PGD 777e9067 PUD 78774067 PMD 0 Oops: 0000 [1] CPU 0 Modules linked in: ecb Pid: 2837, comm: BackupPC_dump Not tainted 2.6.20.3-g691f5333 #40 RIP: 0010:[<ffffffff8031504a>] [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x68 RSP: 0018:ffff8100770bbaf8 EFLAGS: 00010092 RAX: ffff81007fb36c80 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 000000010003e4e7 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff81007fb37a00 R08: 00000000ffffffff R09: ffff81005d390298 R10: ffff81007fcb4f80 R11: ffff81007fcb4f80 R12: ffff81007facd280 R13: 0000000000000004 R14: 0000000000000001 R15: 0000000000000000 FS: 00002b322d120d30(0000) GS:ffffffff805de000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000098 CR3: 000000007bcf0000 CR4: 00000000000006e0 Process BackupPC_dump (pid: 2837, threadinfo ffff8100770ba000, task ffff81007fc5d8e0) Stack: 0000000000000000 ffff8100770f39f0 0000000000000000 0000000000000004 0000000000000001 ffffffff80315253 ffffffff803b2607 ffff81005da2bc40 ffff81007fac3800 ffff81007facd280 ffff81007facd280 ffff81005d390298 Call Trace: [<ffffffff80315253>] cfq_dispatch_requests+0x152/0x512 [<ffffffff803b2607>] scsi_done+0x0/0x18 [<ffffffff8030d9f1>] elv_next_request+0x137/0x147 [<ffffffff803b7ce0>] scsi_request_fn+0x6a/0x33a [<ffffffff8024d407>] generic_unplug_device+0xa/0xe [<ffffffff80407ced>] unplug_slaves+0x5b/0x94 [<ffffffff80223d65>] sync_page+0x0/0x40 [<ffffffff80223d9b>] sync_page+0x36/0x40 [<ffffffff80256d45>] __wait_on_bit_lock+0x36/0x65 [<ffffffff80237496>] __lock_page+0x5e/0x64 [<ffffffff8028061d>] wake_bit_function+0x0/0x23 [<ffffffff802074de>] find_get_page+0xe/0x2d [<ffffffff8020b38e>] do_generic_mapping_read+0x1c2/0x40d [<ffffffff8020bd80>] file_read_actor+0x0/0x118 [<ffffffff8021422e>] generic_file_aio_read+0x15c/0x19e [<ffffffff8020bafa>] do_sync_read+0xc9/0x10c [<ffffffff80210342>] may_open+0x5b/0x1c6 [<ffffffff802805ef>] autoremove_wake_function+0x0/0x2e [<ffffffff8020a857>] vfs_read+0xaa/0x152 [<ffffffff8020faf3>] sys_read+0x45/0x6e [<ffffffff8025041e>] system_call+0x7e/0x83 Code: 4c 8b ae 98 00 00 00 4c 8b 70 08 e8 63 fe ff ff 8b 43 28 4c RIP [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x68 RSP <ffff8100770bbaf8> CR2: 0000000000000098 <1>Unable to handle kernel NULL pointer dereference at 0000000000000098 RIP: [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x68 PGD 79bd2067 PUD 789f9067 PMD 0 Oops: 0000 [2] CPU 0 Modules linked in: ecb Pid: 2834, comm: BackupPC_dump Not tainted 2.6.20.3-g691f5333 #40 RIP: 0010:[<ffffffff8031504a>] [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x 68 RSP: 0018:ffff8100789b5af8 EFLAGS: 00010092 RAX: ffff81007fb36c80 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 000000010007ac16 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff81007fb37a00 R08: 00000000ffffffff R09: ffff810064dd45e0 R10: ffff81007fcb4f80 R11: ffff81007fcb4f80 R12: ffff81007facd280 R13: 0000000000000004 R14: 0000000000000001 R15: 0000000000000000 FS: 00002b0a7c680d30(0000) GS:ffffffff805de000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000098 CR3: 0000000079d36000 CR4: 00000000000006e0 Process BackupPC_dump (pid: 2834, threadinfo ffff8100789b4000, task ffff81007a23 5140) Stack: 0000000000000000 ffff81007b9ebbd0 0000000000000000 0000000000000004 0000000000000001 ffffffff80315253 ffffffff803b2607 ffff81000e67ba00 ffff81007fac3800 ffff81007facd280 ffff81007facd280 ffff810064dd45e0 Call Trace: [<ffffffff80315253>] cfq_dispatch_requests+0x152/0x512 [<ffffffff803b2607>] scsi_done+0x0/0x18 [<ffffffff8030d9f1>] elv_next_request+0x137/0x147 [<ffffffff803b7ce0>] scsi_request_fn+0x6a/0x33a [<ffffffff8024d407>] generic_unplug_device+0xa/0xe [<ffffffff80407ced>] unplug_slaves+0x5b/0x94 [<ffffffff80223d65>] sync_page+0x0/0x40 [<ffffffff80223d9b>] sync_page+0x36/0x40 [<ffffffff80256d45>] __wait_on_bit_lock+0x36/0x65 [<ffffffff80237496>] __lock_page+0x5e/0x64 [<ffffffff8028061d>] wake_bit_function+0x0/0x23 [<ffffffff802074de>] find_get_page+0xe/0x2d [<ffffffff8020b38e>] do_generic_mapping_read+0x1c2/0x40d [<ffffffff8020bd80>] file_read_actor+0x0/0x118 [<ffffffff8021422e>] generic_file_aio_read+0x15c/0x19e [<ffffffff8020bafa>] do_sync_read+0xc9/0x10c [<ffffffff80210342>] may_open+0x5b/0x1c6 [<ffffffff802805ef>] autoremove_wake_function+0x0/0x2e [<ffffffff8020a857>] vfs_read+0xaa/0x152 [<ffffffff8020faf3>] sys_read+0x45/0x6e [<ffffffff8025041e>] system_call+0x7e/0x83 Code: 4c 8b ae 98 00 00 00 4c 8b 70 08 e8 63 fe ff ff 8b 43 28 4c RIP [<ffffffff8031504a>] cfq_dispatch_insert+0x18/0x68 RSP <ffff8100789b5af8> CR2: 0000000000000098 - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html