Are you able to boot without the nr_cpus parameter with older kernels? Was this not happening with prior Ubuntu releases? If you don't know, can you test a prior kernel, maybe the 3.11[0] or 3.2[1] upstream kernel:
[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.11-saucy/ [1] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.2-precise/
Are you able to boot without the nr_cpus parameter with older kernels? Was this not happening with prior Ubuntu releases? If you don't know, can you test a prior kernel, maybe the 3.11[0] or 3.2[1] upstream kernel:
[0] http:// kernel. ubuntu. com/~kernel- ppa/mainline/ v3.11-saucy/ kernel. ubuntu. com/~kernel- ppa/mainline/ v3.2-precise/
[1] http://