On 10/18/2011 10:50 PM, Vivek Goyal wrote: > On Tue, Oct 18, 2011 at 04:45:59PM -0400, Vivek Goyal wrote: >> Hi, > > Oops, got old addresses of dhaval and bablir. Fixing it. Please reply > to this mail instead of previous one. > > Thanks > Vivek > >> >> We have talked a lot of about libcgroup and systemd in the past and when I >> thought that debate is settled, here comes some more things to discuss. >> >> Previously libcg was doing cgroup management and now sytemd is taken over >> a lot of it. >> >> - Creation of hierarchies. Taking control of hierarchies have taken away >> part of the cgconfig functionality. >> >> - Providing automatic cgroups for users has taken away part of the >> functionality provided by cgroup pam plugin. >> >> - Providing automatic cgroups for services has taken away the service >> management which in the past potentially could be done with the help >> of cgconfig. >> >> Now systemd is managing services and users from cgroup point of view >> which past init system never did and that was part of the reason to >> have pam_cgroup plugin and cgconfig. Given the fact that new init >> system has taken over a lot of cgroup management, few things come >> to mind. >> >> - Should systemd provide a way to change default cgroups of users as it >> provides for services. >> >> - Should systemd provide a way to change default resources of cgroups of >> users as it provides for services. >> >> - cgroup and associated resources now become properties of objects being >> managed by systemd (services and users). To me it will make sense >> to provide an API so that an application can call into those APIs >> and manage it. >> >> Should systemd provide an API to manage cgroups and resources of cgroups >> of services and users it is managing. >> >> Lennart, I know you had said that editing the unit file is an API, >> but a real will API will help. >> >> Should cgconfig equivalent functionality be owned by systemd >> ----------------------------------------------------------- >> This is contentious one and I think there are two parts to it. >> >> - Is cgconfig really needed. What are the use cases given the fact that >> systemd now takes care of setting up the system. >> >> - If cgconfig is needed, then who should really manage it. systemd or >> libcg. >> >> I am finding it hard to think of any good use cases of cgconfig now given >> the fact systemd has taken over service and user management. What else is >> left out. Everything is children of either user sessions of services >> and they should manage their own children cgroups. Where's the need >> of statically defining cgroups and resources and what will be launched >> in those. >> >> Even if there is, then it looks like systemd is better place to manage >> it as it already is setting up the whole system and top level hierarchies. >> Thanks to Jason for the suggestion.
Systemd pretty much covers most of the use cases. The main reason to keep separate cgconfig is mounting several controllers together in one hierarchy - AFAIK systemd won't support this mounting. Still, systemd will happily put services to cgroups there. Lennart wrote once on previous discussion [1]: <cite> systemd will create automatic groups for users and services, but will not help you to set up any more complex hierarchy then just 1:1 service to cgroup mappings. As soon as you want a more complex tree, with multiple levels or something like this you will need something like cgconfig which allows you to create any tree you want. </cite> Question is, if we really need complex cgroup hierarchies and/or multiple controllers in a hierarchy. Jan [1]: http://thread.gmane.org/gmane.comp.lib.libcg.devel/3257/focus=3267 ------------------------------------------------------------------------------ Get your Android app more play: Bring it to the BlackBerry PlayBook in minutes. BlackBerry App World™ now supports Android™ Apps for the BlackBerry® PlayBook™. Discover just how easy and simple it is! http://p.sf.net/sfu/android-dev2dev _______________________________________________ Libcg-devel mailing list Libcg-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libcg-devel
