Re: detecting kernel mem leak

From: Stéphane ANCELOT
Date: Fri May 16 2008 - 05:02:32 EST

Christoph Lameter a écrit :
On Tue, 13 May 2008, Stéphane ANCELOT wrote:

I kept my kernel running with few applications for 5 days , doing
nothing more than backing up few kb of data on disk and refresh few X apps.

Ater five days the global memory available go down from 24Mb to 8Mb ...

That is normal. Linux tries to put all memory to use and will free on demand.

The are some signifiant changes in slabinfo but now, I do not know where
to search ?

Compile the slabinfo tool.

gcc -o slabinfo linux/Documentation/vm/slabinfo.c

Then you can do

slabinfo -T

to get an overview of how much is used by slabs. But I do not see that slabs are using an excessive amount. So toying around with slabinfo is not going to get you anywhere.

1) slabinfo tells me SYSFS support for SLUB not active

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

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

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 ?
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 ?

Best Regards

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