Comment 11 for bug 922754

I am seeing similar activity when I attempt to reboot over ssh. The system boots fine and I don't see any high cpu activity from init otherwise. The system will not reboot until I exit the ssh session. This only appears to happen over ssh, it reboots fine otherwise.

Strace on pid 1 yields an endless stream of:
read(11, 0x7f7d8d703730, 8192) = -1 EAGAIN (Resource temporarily unavailable)

With /proc/1/fd/11:
lrwx------ 1 root root 64 Jan 27 15:53 /proc/1/fd/11 -> /dev/ptmx

Which seems to match above. This is on real hardware and here is /proc/cmdline:
BOOT_IMAGE=/boot/vmlinuz-3.2.0-11-generic root=UUID=16258cc4-9dec-421a-9f8e-c0e6632dda7d ro quiet splash vt.handoff=7

The disabled logging in 1.4-0ubuntu4 appears to fix this though, the system reboots immediately without having to exit the ssh session first.