[gentoo-user] Pointers on how to speed up the boot process with systemd

[Marc Stürmer]

Greetings fellow Gentooistas,

I am looking for input on how to speed up my boot process with systemd 
on Gentoo.

First of one word to systemd: Gentoo is about choice, and I choose to 
take a deeper look into systemd out of curiosity, so please respect that 
and don't turn it into another kind of "OpenRC vs. systemd" debate. 
Thanks in advance.

Having said that, now to my setup: I am running the vanilla kernel 
3.13.6 with only the necessary drivers builtin to the kernel, almost 
nothing as module.

Features I don't need are disabled.

Readahead-Services are disabled. Since my root partition is XFS, fsckd 
is disabled.

systemd-analyze says:

Startup finished in 584542y 2w 2d 20h 1min 35.953s (loader) + 1.477s 
(kernel) + 15.966s (userspace) = 17.444s

Blame says:

     1min 7.815s systemd-tmpfiles-clean.service
          4.900s NetworkManager.service
          3.214s systemd-logind.service
          2.585s lightdm.service
          2.373s systemd-vconsole-setup.service
          1.506s systemd-update-utmp.service
           919ms upower.service
           697ms polkit.service
           387ms systemd-udev-trigger.service
           381ms systemd-sysctl.service
           374ms tmp.mount
           359ms udisks2.service
           334ms kmod-static-nodes.service
           333ms user@0.service
           332ms systemd-user-sessions.service
           299ms systemd-tmpfiles-setup-dev.service
           288ms sys-fs-fuse-connections.mount
           287ms systemd-remount-fs.service
           228ms systemd-tmpfiles-setup.service
           178ms systemd-random-seed.service
           117ms systemd-fsck-root.service
           103ms systemd-journal-flush.service
            71ms wpa_supplicant.service
            65ms accounts-daemon.service
            51ms user@1000.service
            35ms systemd-udevd.service
            22ms alsa-restore.service

Critical Chain says:

The time after the unit is active or started is printed after the "@" 
character.
The time the unit takes to start is printed after the "+" character.

graphical.target @15.965s
└─multi-user.target @15.965s
  └─NetworkManager.service @11.065s +4.900s
    └─basic.target @11.065s
      └─timers.target @11.064s
        └─systemd-tmpfiles-clean.timer @11.043s
          └─sysinit.target @4.264s
            └─systemd-vconsole-setup.service @1.891s +2.373s
              └─systemd-journald.socket @1.572s
                └─-.mount @1.571s
                  └─system.slice @1.947s
                    └─-.slice @1.947s

Boot disk is a normal HDD SATA.

GDM-Replacement is lightdm.

So i wonder what could I do to speedup the boot process any further?

Thanks in advance.