Re: OOM-killer and strange RSS value in 3.9-rc7

Christoph Lameter
2013-04-24T15:44:41Z

On Wed, 24 Apr 2013, Michal Hocko wrote:

> [CCing SL.B people and linux-mm list]
>
> Just for quick summary. The reporter sees OOM situations with almost
> whole memory filled with slab memory. This is a powerpc machine with 4G
> RAM.

Boot with "slub_debug" or enable slab debugging.

> /proc/slabinfo shows that almost whole slab occupied memory is on

Please enable debugging and look at where these objects were allocated.

> It is not clear who consumes that memory and the reporter claims this is
> vanilla 3.9-rc7 kernel without any third party modules loaded. The issue
> seems to be present only with CONFIG_SLUB.

cat /sys/kernel/slab/kmalloc-*/alloc_calls

will show where these objects are allocated.

A dump of the other fields in /sys/kernel/slab/kmalloc*/* would also be
useful.