Comment 3 for bug 1130007

Today another guest got stuck:

cat /proc/499/stack
[<ffffffff81084d2a>] __cond_resched+0x2a/0x40
[<ffffffff81144bf2>] isolate_migratepages_range+0xb2/0x5d0
[<ffffffff81145386>] compact_zone+0x1b6/0x350
[<ffffffff811458bf>] try_to_compact_pages+0x16f/0x1d0
[<ffffffff81677a94>] __alloc_pages_direct_compact+0xaa/0x191
[<ffffffff8112bee3>] __alloc_pages_nodemask+0x473/0x920
[<ffffffff81164b30>] alloc_pages_current+0xb0/0x120
[<ffffffff8116bf5d>] new_slab+0x22d/0x2c0
[<ffffffff816790ea>] __slab_alloc+0x314/0x46e
[<ffffffff811708a1>] __kmalloc_node_track_caller+0xa1/0x1b0
[<ffffffff81566e99>] __alloc_skb+0x79/0x230
[<ffffffff81560a31>] sock_alloc_send_pskb+0x1d1/0x320
[<ffffffff81499ec1>] tun_get_user+0x131/0x4a0
[<ffffffff8149a759>] tun_chr_aio_write+0x69/0x90
[<ffffffff8118297a>] do_sync_readv_writev+0xda/0x120
[<ffffffff81182c64>] do_readv_writev+0xd4/0x1e0
[<ffffffff81182da5>] vfs_writev+0x35/0x60
[<ffffffff81182f2a>] sys_writev+0x4a/0xb0
[<ffffffff8168bb69>] system_call_fastpath+0x16/0x1b
[<ffffffffffffffff>] 0xffffffffffffffff