Messages in this thread | | | Date | Tue, 13 Nov 2007 22:12:42 -0800 (PST) | Subject | Re: 2.6.24-rc2: Network commit causes SLUB performance regression with tbench | From | David Miller <> |
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From: Nick Piggin <nickpiggin@yahoo.com.au> Date: Wed, 14 Nov 2007 04:36:24 +1100
> On Wednesday 14 November 2007 12:58, David Miller wrote: > > 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. > > It didn't seem to be noticeable at 1 client. Unless scatterlist > processing is going to cause cacheline bouncing, I don't see why this > hurts more as you add CPUs?
Is your test system using HIGHMEM?
That's one thing the page vector in the sk_buff can do a lot, kmaps. - 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/
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