Messages in this thread | | | Date | Fri, 9 Jan 2009 16:22:55 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC][PATCH] NOOP cgroup subsystem |
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On Fri, 09 Jan 2009 14:44:00 +0800 Li Zefan <lizf@cn.fujitsu.com> wrote:
> Paul Menage wrote: > > On Thu, Jan 8, 2009 at 10:29 PM, Li Zefan <lizf@cn.fujitsu.com> wrote: > >> Agreed, but it can't work by just removing the checking in cgroup mount option, > > > > Right - it's more complicated than that. There are some places in the > > code that rely on the fact that every hierarchy currently has at least > > one subsystem (anything that uses find_first_subsystem() for example) > > and we'd need to work around that. > > > > And some other problems, like what's the semantic of /proc/<pid>/cgroup when > using none subsys. > > I'm afraid even if it's do-able it might require a lot of changes in cgroup. > After quick look, it seems that css_set->subsys==empty case cannot be handled and need much changes. Maintaining hierarchy tree itself seems difficult.
I think cgroup is being stable day by day. So, I don't like to crash it by big hummer for this tiny feature.
How about adding "none" subsys ? (I'd like to set default=y ;)
As Paul said, "Show multiple hierarchy view for each mount point" seems attractive but it's not very fundametal, IMHO. If we can increase subsys_id dynamically or subsys can have multiple root node, the situation will change.
Thanks, -Kame
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