我在戴尔XPS Core 2 Duo塔上运行rsync时，它冻结了。 该机器在3个磁盘上运行Ubuntu 8.04 LTS，3GB RAM和软件RAID 5（mdadm）。 系统在第四张磁盘上。 重启后，我在/var/log/kern.log中发现了这个可爱的gem：
Oct 31 02:38:33 myhostname kernel: [617414.584615] Unable to handle kernel NULL pointer dereference at 0000000000000070 RIP: 然后今天早上又发生了，但日志里有更多的信息（见下文）。 我想知道是否有人能够对这意味着什么有所了解。 不幸的是，这台机器现在距离我3000英里远的一个数据中心，所以换出内存将会非常棘手。
在此先感谢您的任何build议！
Nov 1 01:24:55 myhostname kernel: [34780.996038] Unable to handle kernel NULL pointer dereference at 0000000000000070 RIP: Nov 1 01:24:55 myhostname kernel: [34780.996050] [<ffffffff80470a60>] _spin_lock+0x0/0x10 Nov 1 01:24:55 myhostname kernel: [34780.996099] PGD bb0b5067 PUD bbc91067 PMD 0 Nov 1 01:24:55 myhostname kernel: [34780.996121] Oops: 0002 [1] SMP Nov 1 01:24:55 myhostname kernel: [34780.996140] CPU 1 Nov 1 01:24:55 myhostname kernel: [34780.996156] Modules linked in: nfs lockd nfs_acl sunrpc autofs4 iptable_filter ip_tables x_tables ipv6 parport_pc lp parport loop af_packet serio_raw psmouse button dcdbas intel_agp snd_hda_intel shpchp pci_hotplug iTCO_wdt iTCO_vendor_support evdev snd_pcm snd_timer snd_page_alloc snd_hwdep snd soundcore pcspkr ext3 jbd mbcache sg sr_mod cdrom sd_mod 8139too ata_generic pata_acpi usbhid hid ata_piix 8139cp mii libata scsi_mod ehci_hcd uhci_hcd e1000 usbcore raid10 raid456 async_xor async_memcpy async_tx xor raid1 raid0 multipath linear md_mod thermal processor fan fbcon tileblit font bitblit softcursor fuse Nov 1 01:24:55 myhostname kernel: [34780.996422] Pid: 171, comm: kswapd0 Not tainted 2.6.24-16-server #1 Nov 1 01:24:55 myhostname kernel: [34780.996442] RIP: 0010:[<ffffffff80470a60>] [<ffffffff80470a60>] _spin_lock+0x0/0x10 Nov 1 01:24:55 myhostname kernel: [34780.996474] RSP: 0018:ffff8100b904fd48 EFLAGS: 00010202 Nov 1 01:24:55 myhostname kernel: [34780.996492] RAX: 0000000000000001 RBX: ffff8100167d23c8 RCX: 0000000000000000 Nov 1 01:24:55 myhostname kernel: [34780.996514] RDX: 0000000000000001 RSI: 00000000000000d0 RDI: 0000000000000070 Nov 1 01:24:55 myhostname kernel: [34780.996535] RBP: ffff8100167d2550 R08: 0000000000000000 R09: 0000000000000000 Nov 1 01:24:55 myhostname kernel: [34780.996555] R10: 0000000000000000 R11: ffffffff88232010 R12: 0000000000000028 Nov 1 01:24:55 myhostname kernel: [34780.996576] R13: ffff8100167d24d8 R14: 0000000000000000 R15: 0000000000000000 Nov 1 01:24:55 myhostname kernel: [34780.996597] FS: 0000000000000000(0000) GS:ffff8100bd001700(0000) knlGS:0000000000000000 Nov 1 01:24:55 myhostname kernel: [34780.996628] CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b Nov 1 01:24:55 myhostname kernel: [34780.996647] CR2: 0000000000000070 CR3: 00000000bbd44000 CR4: 00000000000006e0 Nov 1 01:24:55 myhostname kernel: [34780.996668] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Nov 1 01:24:55 myhostname kernel: [34780.996688] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Nov 1 01:24:55 myhostname kernel: [34780.996710] Process kswapd0 (pid: 171, threadinfo ffff8100b904e000, task ffff8100b90487e0) Nov 1 01:24:55 myhostname kernel: [34780.996741] Stack: ffffffff802dc5b2 ffff8100167d23c8 0000000000000080 0000000000000028 Nov 1 01:24:55 myhostname kernel: [34780.996779] ffff8100b904fd80 0000000000000028 ffffffff802cb244 ffff8100167d20d8 Nov 1 01:24:55 myhostname kernel: [34780.996815] ffff810092da43d8 00000000001c4cec 0000000000067714 000000000000009b Nov 1 01:24:55 myhostname kernel: [34780.996839] Call Trace: Nov 1 01:24:55 myhostname kernel: [34780.996868] [remove_inode_buffers+0x42/0x100] remove_inode_buffers+0x42/0x100 Nov 1 01:24:55 myhostname kernel: [34780.996891] [shrink_icache_memory+0x1f4/0x2a0] shrink_icache_memory+0x1f4/0x2a0 Nov 1 01:24:55 myhostname kernel: [34780.996916] [shrink_slab+0x124/0x180] shrink_slab+0x124/0x180 Nov 1 01:24:55 myhostname kernel: [34780.996939] [kswapd+0x391/0x560] kswapd+0x391/0x560 Nov 1 01:24:55 myhostname kernel: [34780.996965] [<ffffffff80254200>] autoremove_wake_function+0x0/0x30 Nov 1 01:24:55 myhostname kernel: [34780.996989] [kswapd+0x0/0x560] kswapd+0x0/0x560 Nov 1 01:24:55 myhostname kernel: [34780.997009] [kthread+0x4b/0x80] kthread+0x4b/0x80 Nov 1 01:24:55 myhostname kernel: [34780.997029] [child_rip+0xa/0x12] child_rip+0xa/0x12 Nov 1 01:24:55 myhostname kernel: [34780.997053] [kthread+0x0/0x80] kthread+0x0/0x80 Nov 1 01:24:55 myhostname kernel: [34780.997072] [child_rip+0x0/0x12] child_rip+0x0/0x12 Nov 1 01:24:55 myhostname kernel: [34780.997091] Nov 1 01:24:55 myhostname kernel: [34780.997104] Nov 1 01:24:55 myhostname kernel: [34780.997105] Code: f0 ff 0f 79 09 f3 90 83 3f 00 7e f9 eb f2 c3 90 f0 81 2f 00 Nov 1 01:24:55 myhostname kernel: [34780.997184] RIP [<ffffffff80470a60>] _spin_lock+0x0/0x10 Nov 1 01:24:55 myhostname kernel: [34780.997205] RSP <ffff8100b904fd48> Nov 1 01:24:55 myhostname kernel: [34780.997221] CR2: 0000000000000070 Nov 1 01:24:55 myhostname kernel: [34780.997458] ---[ end trace 26a2b00c44abedb6 ]---
好吧，这是一个相当标准的内核哎呀。 这可能是由于“进程kswapd0”在磁盘上做了一些不可取的事情造成的。
要检查的事项：1）在所有磁盘上运行smartctl，检查它们是否在推荐的容差范围内运行。
2）在dmesg和/ var / log / messages中有一个戳，看看是否有什么不好的事情同时发生。
3）searchLaunchpad和Ubuntu论坛寻找可能导致此问题的线索，或者在freenode IRC的#ubuntu上询问一些指针。 你可能会被要求更多的信息，如lspci，lsmod等。
有机会，别人也有类似的问题。
4）在一夜之间运行memtest86，看看它是否有任何致盲的内存错误。