Messages in this thread | | | Date | Tue, 13 Nov 2007 17:58:04 -0800 (PST) | Subject | Re: 2.6.24-rc2: Network commit causes SLUB performance regression with tbench | From | David Miller <> |
| |
From: Nick Piggin <nickpiggin@yahoo.com.au> Date: Tue, 13 Nov 2007 22:41:58 +1100
> On Tuesday 13 November 2007 06:44, Christoph Lameter wrote: > > On Sat, 10 Nov 2007, Nick Piggin wrote: > > > BTW. your size-2048 kmalloc cache is order-1 in the default setup, > > > wheras kmalloc(1024) or kmalloc(4096) will be order-0 allocations. And > > > SLAB also uses order-0 for size-2048. It would be nice if SLUB did the > > > same... > > > > You can try to see the effect that order 0 would have by booting with > > > > slub_max_order=0 > > Yeah, that didn't help much, but in general I think it would give > more consistent and reliable behaviour from slub.
Just a note that I'm not ignoring this issue, I just don't have time to get to it yet.
I suspect the issue is about having a huge skb->data linear area for TCP sends over loopback. We're likely getting a much smaller skb->data linear data area after the patch in question, the rest using the sk_buff scatterlist pages which are a little bit more expensive to process.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |