Hello, This is a default fedore 18 machine with default kernel. Kernel came with the F18 disto, no changes. No special things like LXC/OpenVZ. So I guess no 3rd party mount any cgroup.
>then systemd itself will mount all the resource controllers that are compiled into the kernel. How ? I don't know of an API to query from userspace which cgroups are built in into the kernel. Is there such an API ?! I will appreciate if someone will point where in systemd code this mounting of all built in kernel cgroups controllers is done. I suppose that systemd mount all controllers **without** name=systemd, am I right ? because the name=systemd does not appear in any controller except /sys/fs/cgroup/systemd (see the initial post in this thread). Is there a way to know whether a mount was done by systemd or not ? Sorry for so much questions, I simply try to fully understand. Regards, Kevin On Wed, Apr 10, 2013 at 1:14 PM, Daniel P. Berrange <berra...@redhat.com> wrote: > On Wed, Apr 10, 2013 at 12:43:56PM +0300, Kevin Wilson wrote: >> Hello, >> I have a question about systemd and cgroups: >> "mount | grep cgroups" shows that only one entry has name=systemd. >> and is mounted on /sys/fs/cgroup/systemd . (see below the full output >> of "mount | grep cgroups" >> >> Is it true that all other cgroup entry shown by "mount | grep cgroups" >> were not mounted by systemd (and may be unmounted without directly >> causing problems is systemd)? > > If some 3rd party application has mounted cgroups controllers before > systemd starts, it will honour that setup. If they were not already > mounted, then systemd itself will mount all the resource controllers > that are compiled into the kernel. > > Systemd will only actually create sub-dirs in those controllers > that are listed in the 'DefaultControllers' setting of systemd.conf, > which defaults to 'cpu'. > > Daniel > -- > |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| > |: http://libvirt.org -o- http://virt-manager.org :| > |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| > |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
