Re: detecting kernel mem leak

["Pekka Enberg" <penberg@cs.helsinki.fi>]

On Tue, Apr 29, 2008 at 12:41 PM,  <sancelot@free.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