From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
Subject: Re: [PATCH v0 5/5] cgroup: Assign subsystem IDs during compile time
Date: Thu, 16 Aug 2012 16:20:10 -0700
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To: Daniel Wagner <wagi-kQCPcA+X3s7YtjvyW6yDsg@public.gmane.org>
Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Daniel Wagner <daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public.gmane.org>, "David S. Miller" <davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>, Andrew Morton <akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>, Eric Dumazet <edumazet-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>, Gao feng <gaofeng-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org>, Glauber Costa <glommer-bzQdu9zFT3WakBO8gow8eQ@public.gmane.org>, Jamal Hadi Salim <jhs-jkUAjuhPggJWk0Htik3J/w@public.gmane.org>, John Fastabend <john.r.fastabend-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>, Kamezawa Hiroyuki <kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org>, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, Neil Horman <nhorman-2XuSBdqkA4R54TAoqtyWWQ@public.gmane.org>

On Thu, Aug 16, 2012 at 04:12:16PM +0200, Daniel Wagner wrote:
> From: Daniel Wagner <daniel.wagner-98C5kh4wR6ohFhg+JK9F0w@public.gmane.org>
> 
> We are able to safe some space when we assign the subsystem
> IDs at compile time. Instead of allocating per cgroup
> cgroup->subsys[CGROUP_SUBSYS_COUNT] where CGROUP_SUBSYS_COUNT is
> always 64, we allocate 12 + 1 at max (at this point there are 12
> subsystem).

So, IIUC, this is effectively removing the capability to implement
modularized controller which isn't known at kernel compile time.  Am I
right?

I don't think that's a bad idea but if we're doing that, can't we make
things even simpler?  Do we need to distinguish in-kernel and module
at all?

Li, what do you think about this?

Thanks.

-- 
tejun