linux-kernel - Re: detecting kernel mem leak

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 29 Apr 2008 15:46:42 +0300
From:	"Pekka Enberg" <penberg@...helsinki.fi>
To:	sancelot@...e.fr
Cc:	linux-kernel@...r.kernel.org,
	"Christoph Lameter" <clameter@....com>
Subject: Re: detecting kernel mem leak

On Tue, Apr 29, 2008 at 12:41 PM,  <sancelot@...e.fr> wrote:
>  I noticed the memory was growing without doing anything in my system ....after
>  some investigations , it looks like some kernel components may be involved in
>  this problem.
>
>  I would like to know if there is a way to monitor activity of memory (de)alloc
>  of the kernel in order to target which partof the system/kernel could do this..?

You can do

 cat /proc/meminfo | grep Slab

and if that grows too much over time you can do

  cat /proc/slabinfo

or use a tool such as slabtop to see where the memory is going. If the
memory is being leaked in the kmalloc caches, you can use
CONFIG_DEBUG_SLAB_LEAK which part of the kernel is doing all those
allocations (not really suitable for production machines).

Also remember to check that Active + Inactive + Buffers + Cached is
roughly the same size as MemTotal - MemFree; otherwise your kernel
might be leaking full pages.

Christoph, I suppose there's some option to
Documentation/vm/slabinfo.c that provides similar output to
CONFIG_DEBUG_SLAB_LEAK for SLUB?

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