[lxc-devel] /proc/cpuinfo per cgroup

[Serge Hallyn]

Quoting Marian Marinov (mm at yuhu.biz):
> Hi guys,
> I'm using LXC containers for some of my teaching and I want to have /proc/cpuinfo and /proc/memory based on the cgroup 
> limits that I have set.
> 
> The idea is that if one container is limited to a cpuset of 0-1 it should see only the first two cores and not all the 
> cores on the machine.
> 
> The same thing is needed for the memory.
> 
> I simply want my students see the actual resources that they have.
> 
> Does any of you have any suggestions?
> 
> I'm planning to patch the kernel. As far as I can see it, I need to patch the following files:
> ./tile/kernel/proc.c
> ./sh/kernel/cpu/proc.c
> ./x86/kernel/cpu/proc.c
> ./mips/kernel/proc.c
> 
> Actually the c_start function.

Hi,

patching the kernel would be a good exercise.  Historically that hasn't
been acceptable upstream - but then tastes and politics change pretty
frequently, and what was nacked one year can be enthusiastically
accepted two years later...

now the alternative is to use fuse to have userspace change what is
shown in those files.  Daniel Lezcano years ago had one working.  The
code for that is up at https://github.com/hallyn/procfs, however it
won't work or even compile as is.  But if you can whip that into a
working shape we could hopefully figure out how to ship it with lxc.

-serge