There is one other bit that needs to be documented in clone, although I am not certain where/how. The sequences: unshare(CLONE_NEWPID). clone(CLONE_VM) setns(fd, CLONE_NEWPID). clone(CLONE_VM). Now fail. Basically the rule is all threads must be in the same pid namespace. The joy of reviews with good comments that come much later than hoped. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html