Re: [GIT PULL] Lockless SLUB slowpaths for v3.1-rc1

From: Christoph Lameter
Date: Tue Aug 02 2011 - 10:15:11 EST


On Mon, 1 Aug 2011, David Rientjes wrote:

> On Mon, 1 Aug 2011, Pekka Enberg wrote:
>
> > Btw, I haven't measured this recently but in my testing, SLAB has
> > pretty much always used more memory than SLUB. So 'throwing more
> > memory at the problem' is definitely a reasonable approach for SLUB.
> >
>
> Yes, slub _did_ use more memory than slab until the alignment of
> struct page. That cost an additional 128MB on each of these 64GB
> machines, while the total slab usage on the client machine systemwide is
> ~75MB while running netperf TCP_RR with 160 threads.

I guess that calculation did not include metadata structures (alien caches
and the NR_CPU arrays in kmem_cache) etc? These are particularly costly on SLAB.

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