Re: [PATCH 1/2] cgroup allow subsys to set default mode of its ownfile

From: KAMEZAWA Hiroyuki
Date: Thu Feb 26 2009 - 19:22:00 EST


On Thu, 26 Feb 2009 13:00:05 -0800
Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Wed, 25 Feb 2009 16:35:55 +0900
> KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>
> > When I wrote tools for maintain cgroup, I can't find which file is
> > writable intarfece or not via cgroup file systems. (finally, I did
> > dirty approach.)
> > IMHO, showing "this file is read-only" in explicit way is useful
> > for user-land (tools). In other story, a file whose name sounds read-only
> > may have "trigger" operation and support reseting. In this case,
> > "writable" is informative.
>
> Well, we have compatibility issues here. If we make this change, and
> people write tools which depend upon that change then those tools might
> break when run upon older kernels. Or they need back-compatibility
> additions, which increases the testing burden of those tools.
>
> One way in which we could improve this situation is to backport these
> changes into earlier kernels, although I don't know which versions.
>
> What do we think?
>
It sounds problem to me.

Hmm..1st commit to kernel/cgroup.c is 2007-10-19, then 2.6.24 is the oldest one.
But I think distro's tools for cgroup is not as old as...
Hmm, backport to 2.6.25 is enough ?
Balbir, how do you think ? I think you are familiar with libcgroup.

Thanks,
-Kame

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/