I did some more debugging, and the problem appears to be that booting with nosmp still leaves all the CPU's present in the cpu possible mask. So code like dma engine (or loopback device), that use alloc_percpu get broken. Not sure why all the cpu's are still showing up in the possible mask. Rusty? do you have an answer. -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html