I've seen this behaviour at least five times in the last month too; it probably happens when there's an apparmor upgrade. Both the cpu cores are in wait mode, the load average skyrockets to ~25 and the system becomes unusable. With some patience I usually switch to tty, login as root and kill some random stuff. Usually killing networkmanager and nm-applet brings things back to normal. One time I fixed it rmmod-ing and reloading 'iwlagn'.
Here's some junk from `dmesg` that probably explains it:
I've seen this behaviour at least five times in the last month too; it probably happens when there's an apparmor upgrade. Both the cpu cores are in wait mode, the load average skyrockets to ~25 and the system becomes unusable. With some patience I usually switch to tty, login as root and kill some random stuff. Usually killing networkmanager and nm-applet brings things back to normal. One time I fixed it rmmod-ing and reloading 'iwlagn'.
Here's some junk from `dmesg` that probably explains it:
[1138553.650102] udev: starting version 151 5.954:56) : operation= "profile_ replace" pid=26791 name="/ usr/share/ gdm/guest- session/ Xsession" 5.964:57) : operation= "profile_ replace" pid=26792 name="/ sbin/dhclient3" 5.964:58) : operation= "profile_ replace" pid=26792 name="/ usr/lib/ NetworkManager/ nm-dhcp- client. action" 5.974:59) : operation= "profile_ replace" pid=26792 name="/ usr/lib/ connman/ scripts/ dhclient- script" 42e>] __alloc_ pages_slowpath+ 0x56e/0x580 59e>] __alloc_ pages_nodemask+ 0x15e/0x1a0 3d7>] alloc_pages_ current+ 0x87/0xd0 4ae>] __get_free_ pages+0xe/ 0x50 c4b>] __kmalloc+ 0x14b/0x1d0 a62>] kvmalloc+0x22/0x40 aee>] aa_simple_ write_to_ buffer+ 0x6e/0x140 7c9>] ? default_ spin_lock_ flags+0x9/ 0x10 c41>] aa_profile_ replace+ 0x21/0x60 0b8>] vfs_write+ 0xb8/0x1a0 951>] sys_write+0x51/0x80 1f2>] system_ call_fastpath+ 0x16/0x1b anon:118219 isolated_anon:0 file:239394 isolated_file:136 e:39329 slab_unreclaima ble:24299 e:224kB slab_unreclaima ble:8kB kernel_stack:0kB pagetables:0kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no anon:974156kB inactive_ anon:263260kB active_ file:572620kB inactive_ file:888084kB unevictable:32kB isolated(anon):0kB isolated( file):544kB present:3029636kB mlocked:32kB dirty:5072kB writeback:0kB mapped:81636kB shmem:175948kB slab_reclaimabl e:141856kB slab_unreclaima ble:62984kB kernel_stack:976kB pagetables:18592kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no anon:182296kB inactive_ anon:209616kB active_file:71264kB inactive_ file:69476kB unevictable:16kB isolated(anon):0kB isolated(file):0kB present:969600kB mlocked:16kB dirty:152kB writeback:0kB mapped:58652kB shmem:122692kB slab_reclaimabl e:15236kB slab_unreclaima ble:34204kB kernel_stack:2280kB pagetables:22480kB unstable:0kB bounce:0kB writeback_tmp:0kB pages_scanned:0 all_unreclaimable? no 6.235:60) : operation= "profile_ replace" pid=26793 name="/ usr/bin/ evince" 6.245:61) : operation= "profile_ replace" pid=26793 name="/ usr/bin/ evince- previewer" 6.245:62) : operation= "profile_ replace" pid=26793 name="/ usr/bin/ evince- thumbnailer" 6.305:63) : operation= "profile_ load" pid=26795 name="/ usr/lib/ firefox- 3.7a3pre/ firefox{ ,*[^s][ ^h]}" 4.544:69) : operation= "profile_ replace" pid=26827 name="/ usr/share/ gdm/guest- session/ Xsession" 8.795:70) : operation= "profile_ replace" pid=26837 name="/ sbin/dhclient3" 8.795:71) : operation= "profile_ replace" pid=26837 name="/ usr/lib/ NetworkManager/ nm-dhcp- client. action" 8.795:72) : operation= "profile_ replace" pid=26837 name="/ usr/lib/ connman/ scripts/ dhclient- script" 4.985:73) : operation= "profile_ replace" pid=26843 name="/ usr/bin/ evince" 4.995:74) : operation= "profile_ replace" pid=26843 name="/ usr/bin/ evince- previewer" 4.995:75) : operation= "profile_ replace" pid=26843 name="/ usr/bin/ evince- thumbnailer" 7.314:76) : operation= "profile_ replace" pid=26857 name="/ usr/lib/ firefox- 3.7a3pre/ firefox{ ,*[^s][ ^h]}" 8.974:77) : operation= "profile_ replace" pid=26863 name="/ usr/lib/ cups/backend/ cups-pdf" 8.974:78) : operation= "profile_ replace" pid=26863 name="/ usr/sbin/ cupsd" 0.594:79) : operation= "profile_ replace" pid=26866 name="/ usr/sbin/ mysqld- akonadi" 6.974:80) : operation= "profile_ replace" pid=26923 name="/ usr/sbin/ named" 1.694:81) : operation= "profile_ replace" pid=26924 name="/ usr/sbin/ tcpdump" 7.365:82) : operation= "profile_ remove" pid=26977 name="/ usr/lib/ firefox- 3.7a3pre/ firefox{ ,*[^s][ ^h]}" namespace="root"
[1138562.167699] type=1505 audit(127004141
[1138562.177594] type=1505 audit(127004141
[1138562.179275] type=1505 audit(127004141
[1138562.180189] type=1505 audit(127004141
[1138562.401339] apparmor_parser: page allocation failure. order:8, mode:0x40d0
[1138562.401349] Pid: 26793, comm: apparmor_parser Not tainted 2.6.32-16-generic #25-Ubuntu
[1138562.401356] Call Trace:
[1138562.401376] [<ffffffff810f7
[1138562.401386] [<ffffffff810f7
[1138562.401397] [<ffffffff8112a
[1138562.401405] [<ffffffff810f6
[1138562.401413] [<ffffffff81133
[1138562.401426] [<ffffffff81279
[1138562.401434] [<ffffffff81279
[1138562.401446] [<ffffffff81039
[1138562.401454] [<ffffffff81279
[1138562.401464] [<ffffffff81140
[1138562.401472] [<ffffffff81140
[1138562.401483] [<ffffffff81013
[1138562.401488] Mem-Info:
[1138562.401492] Node 0 DMA per-cpu:
[1138562.401499] CPU 0: hi: 0, btch: 1 usd: 0
[1138562.401504] CPU 1: hi: 0, btch: 1 usd: 0
[1138562.401508] Node 0 DMA32 per-cpu:
[1138562.401514] CPU 0: hi: 186, btch: 31 usd: 0
[1138562.401520] CPU 1: hi: 186, btch: 31 usd: 0
[1138562.401524] Node 0 Normal per-cpu:
[1138562.401530] CPU 0: hi: 186, btch: 31 usd: 0
[1138562.401535] CPU 1: hi: 186, btch: 31 usd: 0
[1138562.401547] active_anon:289113 inactive_
[1138562.401550] active_file:160971 inactive_
[1138562.401552] unevictable:12 dirty:1306 writeback:0 unstable:0
[1138562.401555] free:10068 slab_reclaimabl
[1138562.401557] mapped:35072 shmem:74660 pagetables:10268 bounce:0
[1138562.401563] Node 0 DMA free:15648kB min:28kB low:32kB high:40kB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:16kB unevictable:0kB isolated(anon):0kB isolated(file):0kB present:15304kB mlocked:0kB dirty:0kB writeback:0kB mapped:0kB shmem:0kB slab_reclaimabl
[1138562.401587] lowmem_reserve[]: 0 2958 3905 3905
[1138562.401599] Node 0 DMA32 free:21348kB min:6044kB low:7552kB high:9064kB active_
[1138562.401625] lowmem_reserve[]: 0 0 946 946
[1138562.401635] Node 0 Normal free:3276kB min:1932kB low:2412kB high:2896kB active_
[1138562.401661] lowmem_reserve[]: 0 0 0 0
[1138562.401671] Node 0 DMA: 0*4kB 2*8kB 1*16kB 4*32kB 4*64kB 1*128kB 3*256kB 2*512kB 3*1024kB 3*2048kB 1*4096kB = 15648kB
[1138562.401696] Node 0 DMA32: 1839*4kB 293*8kB 136*16kB 220*32kB 6*64kB 2*128kB 1*256kB 1*512kB 1*1024kB 0*2048kB 0*4096kB = 21348kB
[1138562.401720] Node 0 Normal: 593*4kB 31*8kB 1*16kB 0*32kB 2*64kB 0*128kB 2*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 3276kB
[1138562.401743] 475038 total pagecache pages
[1138562.401747] 0 pages in swap cache
[1138562.401753] Swap cache stats: add 54728, delete 54728, find 83949/85128
[1138562.401758] Free swap = 0kB
[1138562.401761] Total swap = 0kB
[1138562.442506] 1032192 pages RAM
[1138562.442511] 44196 pages reserved
[1138562.442515] 442162 pages shared
[1138562.442519] 703082 pages non-shared
[1138562.444565] type=1505 audit(127004141
[1138562.455414] type=1505 audit(127004141
[1138562.459073] type=1505 audit(127004141
[1138562.516253] type=1505 audit(127004141
[1138600.751741] __ratelimit: 15 callbacks suppressed
[1138600.751748] type=1505 audit(127004145
[1138635.007138] type=1505 audit(127004148
[1138635.007380] type=1505 audit(127004148
[1138635.007548] type=1505 audit(127004148
[1138641.200432] type=1505 audit(127004149
[1138641.202107] type=1505 audit(127004149
[1138641.203564] type=1505 audit(127004149
[1138643.522317] type=1505 audit(127004149
[1138645.187709] type=1505 audit(127004149
[1138645.187845] type=1505 audit(127004149
[1138646.801729] type=1505 audit(127004150
[1138653.180926] type=1505 audit(127004150
[1138657.904154] type=1505 audit(127004151
[1138703.573151] type=1505 audit(127004155