Re: [this_cpu_xx V6 7/7] this_cpu: slub aggressive use of this_cpuoperations in the hotpaths

[David Rientjes]

On Fri, 16 Oct 2009, Christoph Lameter wrote:

> > TCP_STREAM stresses a few specific caches:
> >
> > 		ALLOC_FASTPATH	ALLOC_SLOWPATH	FREE_FASTPATH	FREE_SLOWPATH
> > kmalloc-256	3868530		3450592		95628		7223491
> > kmalloc-1024	2440434		429		2430825		10034
> > kmalloc-4096	3860625		1036723		85571		4811779
> >
> > This demonstrates that freeing to full (or partial) slabs causes a lot of
> > pain since the fastpath normally can't be utilized and that's probably
> > beyond the scope of this patchset.
> >
> > It's also different from the cpu slab thrashing issue I identified with
> > the TCP_RR benchmark and had a patchset to somewhat improve.  The
> > criticism was the addition of an increment to a fastpath counter in struct
> > kmem_cache_cpu which could probably now be much cheaper with these
> > optimizations.
> 
> Can you redo the patch?
> 

Sure, but it would be even more inexpensive if we can figure out why the 
irqless patch is hanging my netserver machine within the first 60 seconds 
on the TCP_RR benchmark.  I guess nobody else has reproduced that yet.
--
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/