# Re: SO\_REUSEPORT - can it be done in kernel?

- From: Rick Jones \<hidden\>
- Date: 2011-02-25 19:18:19 
- List: netdev
- Page: https://ratatoskr.run/netdev/2011/02/10864886
- Thread: https://ratatoskr.run/netdev/2011/01/10863115/t.md

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On Fri, 2011-02-25 at 07:56 -0500, Thomas Graf wrote:
> On Thu, Jan 27, 2011 at 01:32:25PM -0800, Tom Herbert wrote:
> > Yes, we are still planning this.  The UDP implementation for my
> > earlier patch should be usable to try for DNS/UDP-- this is in fact
> > where we saw a major performance gain.  Eric Dumazet had some nice
> > improvements that should probably be looked at also.
> 
> I can confirm this.
> 
> Serious scalability issues have been reported on a 12 core system
> running bind 9.7-2. The system was only able to deliver ~110K queries
> per second.
> 
> Using your SO_REUSEPORT patch and a modified bind using it. The same
> system is able to deliver ~650K queries per seconds while maxing out
> all cores completely.

I think the idea is goodness, but will ask, was the (first) bottleneck
actually in the kernel, or was it in bind itself?  I've seen
single-instance, single-byte burst-mode netperf TCP_RR do in excess of
300K transactions per second (with TCP_NODELAY set) on an X5560 core.

ftp://ftp.netperf.org/netperf/misc/dl380g6_X5560_rhel54_ad386_cxgb3_1.4.1.2_b2b_to_same_agg_1500mtu_20100513-2.csv

and that was with now ancient RHEL5.4 bits...  yes, there is a bit of
apples, oranges and kumquats but still, I am wondering if this didn't
also "work around" some internal BIND scaling issues as well.

rick jones

> 
> Tom, Bill: do you have a timeline for merging this? Especially the
> UDP bits?
> 
> -Thomas
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