In the LWN article linked by another commentator: "Tom Gundersen, one of the authors, acknowledged that having a dedicated system call to create a peer, and to

In the LWN article linked by another commentator: "Tom Gundersen, one of the authors, acknowledged that having a dedicated system call to create a peer, and to perform the various other operations that currently use ioctl(), might make more sense for eventual upstream submission. Devices and ioctl() have been used so far because they make out-of-tree development easier." So I think using ioctl is a prototyping concession. I'm not an expert on this matter but I think it is the Android devs that want it not Red Hat it is similar to the android specific BINDER IPC mechanism but with multicast support.