Linode locked up

This morning my Linode was locked up tighter than hell. It wouldn't respond to any input so I had to reboot it from the web interface. It rebooted slower than molasses in January but finally was running again. After perusing my logs I find entry after entry like this;

> May 1 04:48:10 host DMA free:1616kB min:1616kB low:2020kB high:2424kB active:62296kB inactive:61880kB present:163840kB pagesscanned:132427 allunreclaimable? yes

May 1 04:48:20 host lowmem_reserve[]: 0 0 0 0

May 1 04:48:20 host DMA32 free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB present:0kB pagesscanned:0 allunreclaimable? no

May 1 04:48:20 host lowmem_reserve[]: 0 0 0 0

May 1 04:48:20 host Normal free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB present:0kB pagesscanned:0 allunreclaimable? no

May 1 04:48:20 host lowmem_reserve[]: 0 0 0 0

May 1 04:48:20 host HighMem free:0kB min:128kB low:128kB high:128kB active:0kB inactive:0kB present:0kB pagesscanned:0 allunreclaimable? no

May 1 04:48:20 host lowmem_reserve[]: 0 0 0 0

May 1 04:48:20 host DMA: 04kB 48kB 6116kB 532kB 164kB 1128kB 1256kB 0512kB 01024kB 02048kB 0*4096kB = 1616kB

May 1 04:48:20 host DMA32: empty

May 1 04:48:20 host Normal: empty

May 1 04:48:20 host HighMem: empty

May 1 04:48:20 host Swap cache: add 8083509, delete 8083335, find 1081307/2342382, race 6+251

May 1 04:48:20 host Free swap = 8kB

May 1 04:48:20 host Total swap = 359416kB

May 1 04:48:20 host Free swap: 8kB

May 1 04:48:20 host 40960 pages of RAM

May 1 04:48:20 host 0 pages of HIGHMEM

May 1 04:48:20 host 2161 reserved pages

May 1 04:48:31 host 244 pages shared

May 1 04:48:31 host 174 pages swap cached

May 1 04:48:31 host oom-killer: gfp_mask=0x201d2, order=0

May 1 04:48:31 host 89b73a2c: [<80066c0e>] outofmemory+0xa4/0xba

May 1 04:48:31 host 89b73a4c: [<80067b8f>] _allocpages+0x270/0x30f

May 1 04:48:31 host 89b73a7c: [<8001a1ca>] physmemremovemapping+0x14/0x2d

May 1 04:48:31 host 89b73a94: [<80069ef0>] _dopagecachereadahead+0x10c/0x156

May 1 04:48:31 host 89b73aa4: [<8006a395>] maxsanereadahead+0x2f/0x4a

May 1 04:48:31 host 89b73ac8: [<80064473>] filemap_nopage+0x27a/0x345

May 1 04:48:31 host 89b73b04: [<80070393>] donopage+0x65/0x224

May 1 04:48:31 host 89b73b14: [<800232ed>] copytouser_skas+0xc4/0x104

May 1 04:48:31 host 89b73b34: [<800706b6>] _handlemm_fault+0xea/0x1f3

May 1 04:48:31 host 89b73b68: [<8001e5d8>] handlepagefault+0x110/0x233

May 1 04:48:31 host 89b73bac: [<8001e878>] segv+0x99/0x2c0

May 1 04:48:31 host 89b73bf4: [<80022b45>] handle_syscall+0x12d/0x138

May 1 04:48:31 host 89b73c60: [<80032dec>] getskasfaultinfo+0x35/0x94

May 1 04:48:31 host 89b73c78: [<80032ea6>] handle_segv+0x5b/0x63

Can anybody tell me what this means and what caused it. I am running gentoo distrbution (~x86) on a linode 160 using the 2.6.16.1-linode18 kernel. For a while after reboot it continued to run slow but has finally has returned to normal.