[systemd-devel] [PATCH v2 1/4] cgroup: add the setting memory.use_hierarchy support for systemd

[Lennart Poettering]

On Tue, 24.09.13 08:36, Gao feng (gaofeng at cn.fujitsu.com) wrote:

> >> Some programs need to set the memory.use_hierarchy(such as libvirt),
> >> Add this feature.
> > 
> > As mentioned already: this really shouldn't be configurable but simply
> > the unconditional configuration that systemd requires. I have hence now
> > commited a different patch that strictly enables this option at
> > boot-time in the root memory hierarchy and does not turn this into yet
> > another user config switch.
> 
> So administrator has no rights to set use_hierarchy to false?

Yes. use_hierarchy=0 is a bad idea, and exists only for legacy
reasons. Since we kinda break compat with the systemd-based cgroup
rework this should not exist in systemd ever, especially since Tejun
already clearly said that this option will go away in the kernel too,
and will be implicitly on.

> This patchset enables use_hierarchy for unit by default. but give
> users the rights to disable this.

We should never blindly add more options for users, unless the interface
is known to be useful and nicely designed, and if we know the setting
has a future. This option is both badly designed on the kernel side and
has no future on the kernel side hence it really doesn't belong in
systemd's interfaces.

Sorry, 

Lennart

-- 
Lennart Poettering - Red Hat, Inc.