Red Hat Bugzilla – Bug 428950
Memory leak (slub) with kernel 2.6.23
Last modified: 2008-01-18 18:11:53 EST
Description of problem:
There is a memory leak in the 2.6.23 kernel that comes with a "yum upgrade" on
fedora7-amd64. Same problem with 126.96.36.199-10.fc7 and kernel-188.8.131.52-52.fc7.
The slabinfo program reports that the slub ":0000016" is groing quicky, and the
4GB server was out of memory after few week of very low activity, and it was not
able to process the network packets (it's a firewall).
Version-Release number of selected component (if applicable):
Linux hostname 184.108.40.206-10.fc7 #1 SMP Fri Oct 19 14:35:28 EDT 2007 x86_64 x86_64
Don't know what kernel module involved in allocating this slub. Our hardware is
an HP-Proliant-DL140-G3 server with 2 CPUs (2 Quad Core).
Steps to Reproduce:
1. install fedora7-amd64 on HP-Proliant-DL140-G3
2. upgrade to 220.127.116.11-10.fc7 or kernel-18.104.22.168-52.fc7
3. use only some network applications (shorewall/iptables, ssh)
I made a script to monitor the memory leak of the "16bytes" slub object. Here is
We had exactly the same problem on two servers. The two servers have the same
hardware (HP-Proliant-DL140-G3) since they are redundant firewalls. The problem
was reported by a script when the memory was already very low (after an uptime
of few weeks). Both servers have a very low activity.
Here are other details:
Whe noticed the problem when the servers were very slow to respond to the ssh
connections. We noticed the CPU was very busy just because it was waiting IO
(all the processes were around 0% of the CPUs). It is just a consequence of the
kernel not able to allocate memory. (http://pastebin.com/f20a67f4d)
Here is the slabinfo output just before we reboot the server:
Before rebooting, some kernel threads crashed:
Rebooting the server allowed us to connect to the server again, but the memory
leak is still running.
Here are the kernel modules currently loaded on one of the servers that is still
tunning with the memory leak: http://pastebin.com/f64858e3d
Can you boot with the kernel option slub_debug=U
Also see bug 352281
Thanks for your quick reply. It seems to be the same bug as 352281 since 16bytes
objects are involved.
Unfortunately I cannot reboot the server since it would break all the current
connections. All I can do is collecting information on the system with the
memory leak that is currently running. Thanks.
Closing as dup of 352281.
*** This bug has been marked as a duplicate of 352281 ***