Re: detecting kernel mem leak

From: Christoph Lameter
Date: Fri May 16 2008 - 14:53:17 EST

On Fri, 16 May 2008, Stéphane ANCELOT wrote:

> In the kernel, there is SLAB or SLUB , my kernel is at this time configured
> for SLAB allocator.

SLAB does not support the slabinfo tool. It only supports /proc/slabinfo.

> it is documented SLUB minimizes cache line usage.
> Do you think I have to switch to SLUB ?

If you want to use the slabinfo tool then yes.

> 2) regarding memory debugging, your reply and some mesages told it was normal
> the memory was growing (with ext3 buffer_heads...) and released on demand.
> This sounds to me it becomes VERY VERY difficult telling if my system is
> STABLE or NOT. Is there a way to bypass it ?

This the basic design of memory handling in Linux. Why would the use of
memory mean that your system is unstable?

> I assume I have to do some kind of small program trying to allocate almost the
> full remaining memory available at startup to empty caches ?

There is a way to drop caches. See what you can do with


echo 1 >/proc/sys/vm/drop_caches
echo 2 >/proc/sys/vm/drop_caches

Should free most of memory.