systemd ties units to a processes via cgroups and cgroups only, it's an absolute requirement for systemd to run. No cgroups support in kernel = no systemd. Period.
That said, you can disable resource controllers, like cpu, blkio, etc, they are indeed optional, but not the cgroups feature itself.
Posted Aug 2, 2011 7:46 UTC (Tue) by rahulsundaram (subscriber, #21946)
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I just did the initial packaging work and got it into the distribution and wrote up the feature page so Lennart and others have time to do the real work. Feel free to look at the source when in doubt. These patches will get you a system that boots but won't have all the functionality that relies on cgroups.