On Mon, Jun 08, 2009 at 03:39:51PM +0900, Minoru Usui wrote:

Hi Thomas

On Mon, 1 Jun 2009 18:12:01 +0900
Minoru Usui [off-list ref] wrote:

quoted

Hi Thomas

Original mail sent to netdev and containers before.
(http://www.spinics.net/lists/netdev/msg97745.html)

I have a question about how to use cls_cgroup.

On Thu, 21 May 2009 09:22:56 +0900
Minoru Usui [off-list ref] wrote:

quoted

Hi

Unfortunately this is only panic report.

I used cgroup net_cls subsystem, then kernel panic occured.
I attach panic message and kernel config in this mail's last paragraph.
If my operation is wrong, could you tell me how to use net_cls and
where the documentation is. 

# But I think panic is very bad even if my operation is wrong.

The cause of panic will fix soon. (Now I'll make a patch and will test it.)

I want to know how to use cls_cgroup correctly, so could you tell me how to use it if my operation is wrong. 
Now, I think I might have to specify 'handle' with tc command line, is this true?
But when I specified 'handle', I faced oops. X-P

I investigated this problem, and I found a bug in cls_cgroup_change() in cls_cgroup.c.
cls_cgroup_change() expected tca[TCA_OPTIONS] was set from user space properly,
but tc in iproute2-2.6.29-1 (which I used) didn't set it.

I saw the current source code of tc in git, I found the code for cls_cgroup in iproute2/tc/f_cgroup.c.
It set tca[TCA_OPTIONS].

  git://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git

# Unfortunately, current source coude of iproute2 couldn't compile, because it occured compile error. X-P
# But this is another issue.

If we always use a newest iproute2 in git when we use cls_cgroup, we don't face this oops probably.
But I think, kernel shouldn't panic regardless of use program's behaviour. 

This patch looks OK to me, but I guess you should add some title (plus
"[PATCH]" in the subject), and a changelog (with lines width <= 80).

Cheers,
Jarek P.