[systemd-devel] Services started realtime exit with 214

[Barry Scott]

On Monday 11 July 2011 17:27:26 Lennart Poettering wrote:
> On Mon, 11.07.11 12:40, Barry Scott (barry.scott at onelan.co.uk) wrote:
> 
> > Do we have to configure something else to get this working like cgroup stuff?
> 
> Running X under RR privs? That's bold.

It is the only way we found to guarentee that Xorg will keep up with 60Hz frame
rates. We found that it is stable in our use at RR.

> 
> I figure this fails due to the fact that by default we place every
> service in its own cgroup in the "cpu" hierarchy, in order to distribute
> the available CPU time evenly among the available processes. However,
> because the "cpu" controller currently isn't that nice to use this
> breaks RT, since if you create a group to allow it RT you need to assign
> an RT budget to it, which we however cannot really do, since we cannot
> come up with any sane default for it.
> 
> There are two ways out of this:
> 
> a) disable the implicit sortining into separate cpu cgroups globally, by
> setting "DefaultControllers=" (i.e. setting it to the empty string) in
> /etc/systemd/system.conf
> 
> or
> 
> b) disable the automatic creation of a "cpu" cgroup only for this one
> service, by placing "ControlGroup=cpu:/" in it.
> 
> I recommend the latter.

Done and it works. Thanks.

> 
> That this is necessary is very unfortunate and I really hope the cpu
> controller can be fixed one day, so that RT budgets and normal
> scheduling budgets are independent.

I second that.

Barry