Oddly, a recent kernel (23fd50450a34f2558070ceabb0bfebc1c9604af5) stops booting at "windfarm: Drive bay control loop started.", while previously "windfarm: CPUs control loops started" was displayed a long time, i.e. Backside took very long to start. Haven't had a chance to look into it yet, any ideas? I do have NO_HZ enabled. I wanted to test the irqtrace patch but I doubt it would be causing this, usually bugs there caused hangs very early, not this late in the boot sequence. johannes