linux-kernel - PROBLEM: Crash cgdeleting empty memory cgroups with memory.kmem.limit_in

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Message-ID: <1361375371.7786.5.camel@michalke-online.eu>
Date:	Wed, 20 Feb 2013 16:49:31 +0100
From:	Steffen Michalke <StMichalke@....de>
To:	linux-kernel@...r.kernel.org
Subject: PROBLEM: Crash cgdeleting empty memory cgroups with
 memory.kmem.limit_in_bytes set

Linux version 3.8.0 (root@...ky) (gcc version 4.7.2 20130205
[gcc-4_7-branch revision 195759] (SUSE Linux) ) #1 Wed Feb 20 02:08:17
CET 2013

The kernel v3.8 crashes if I remove an empty memory cgroup by cgdelete.

To reproduce that behaviour do the following:

~ # bash
~ # cgcreate -g memory:$$
~ # cgset -r memory.kmem.limit_in_bytes=402653184 $$
~ # cgclassify -g memory:$$ $$
~ # echo $$ > temp
~ # <CTRL>-D
~ # cgdelete memory:`cat temp`

The last step can be automated by setting an appropriate release_agent and
setting notify_on_release=1, of course.

Additional software used: libcgroup 0.37.1

I enclosed the last lines of /var/log/message which were written before I hard
reset the box. I don't know, whether another message followed.

Additionally, config.38 is the .config file for building the affected kernel.

View attachment "config.38" of type "text/x-mpsub" (78317 bytes)

View attachment "kernel.out" of type "text/plain" (7191 bytes)

View attachment "proc_iomem" of type "text/plain" (1346 bytes)

View attachment "proc_modules" of type "text/plain" (5140 bytes)