[Bloat] [Cerowrt-devel] beating the drum for BQL

[Toke Høiland-Jørgensen]

Dave Taht <dave.taht at gmail.com> writes:

> On Thu, Aug 23, 2018 at 2:01 PM Toke Høiland-Jørgensen <toke at toke.dk> wrote:
>>
>> Dave Taht <dave.taht at gmail.com> writes:
>>
>> > One of the things not readily evident in trying to scale up, is the
>> > cost of even the most basic routing table lookup. A lot of good work
>> > in this area landed in linux 4.1 and 4.2 (see a couple posts here:
>> > https://vincent.bernat.im/en/blog/2017-performance-progression-ipv4-route-lookup-linux
>> > )
>> >
>> > Lookup time for even the smallest number of routes is absolutely
>> > miserable for IPv6 -
>> > https://vincent.bernat.im/en/blog/2017-ipv6-route-lookup-linux
>>
>> The IPv6 routing lookup is on par with v4 these days. We got 7.2M pkts/s
>> in our XDP tests on a single core (although admittedly a fairly high-end
>> Intel one). Which allows you to route 10Gbps of 64-byte packets on two
>> cores...
>
> Call me cynical, call me grumpy...
>
> but did you get that result with testing 1,10,100,1000, 10,000, 100k,
> 1M routes? The best
> case performance on that test looked like .150us, the worst case
> 1.75us

Think those were single-route tests, or close to it. Don't have results
handy for large routing tables for IPv6, but IPv4 performance drops by
~33% when going from a single route to a full BGP table dump...

Can run some tests for v6 once by testbed is running again...

-Toke