systemd and Login Sessions

Most major distributions have adopted or are in the process of adopting systemd as system and service manager, replacing older init systems. However, systemd is not only useful for improving system bootup, but also login session startup. In this talk I will try to explain in detail why we think starting sessions with systemd is a good thing and what win by adopting it. I'll discuss the technical details, where precisely we are with this, and where we want to go, what the requirements are, and what changes will be necessary on other software. This will cover a lot of technologies, such as the new D-Bus user bus, kernel changes, and the relation to existing desktop-specific session managers.

The initial focus of this work is making GNOME boot with systemd as login session manager. However, the work is very relevant for other desktops, too. Our hope is that eventually the session manager is considered more part of the OS, and less of the desktop, which would allow us to run all different desktops with the same session manager, and mix and match parts normally part of the different desktops more freely, while making maximum use of the modern features of the Linux kernel which systemd exposes.

Other operating systems (such as MacOS with launchd) already use the same implementation for managing the system and the user sessions, and have shown that this brings great advantages. On Linux, we can and should take advantage of the same ideas, and in this talk I hope to explain why and how.