[Ecn-sane] Fwd: [bbr-dev] Applying BBRv2 patches

[Ecn-sane] Fwd: [bbr-dev] Applying BBRv2 patches

[Dave Taht]

---------- Forwarded message ---------
From: 'Neal Cardwell' via BBR Development <bbr-dev@googlegroups.com>
Date: Tue, Mar 12, 2019 at 10:29 PM
Subject: Re: [bbr-dev] Applying BBRv2 patches
To: Jared Newman <jnewman2501@gmail.com>
Cc: BBR Development <bbr-dev@googlegroups.com>


Hi,

For the patches in
https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY there were
two main features:

(1) Higher throughput for wifi and other paths with aggregation

(2) Lower queuing delays by frequently draining excess in-flight data


For the patches related to (1), that functionality is already in
davem/net-next and torvalds/linux, as of recently, and those patches
will be in Linux 5.1. We were waiting until Linux 5.1 is released to
announce that on this e-mail list. But since it came up anyway, we may
as well mention it. ;-)


For the patches related to (2), that functionality is still undergoing
testing on YouTube and elsewhere.


If you want to apply the original patches from
https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY  then you
can apply them on top of the Linux commit:

18845557fd6f

from March 2018. That's where they were originally generated.


best,

neal



On Tue, Mar 12, 2019 at 10:09 PM Jared Newman <jnewman2501@gmail.com> wrote:
>
> Hey BBR-dev,
>
> I'm trying to apply the patches given in https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY, but am struggling to find what commit of next-net I should apply them on. I tried a couple different tags in https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git but would always get conflicts that I didn't feel comfortable resolving. Does anyone have a suggestion / commit hash to apply them to?
>
> Cheers,
> Jared.
>
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Re: [Ecn-sane] [bbr-dev] Applying BBRv2 patches

[Dave Taht]

On Thu, Mar 14, 2019 at 11:21 AM Jared Newman <jnewman2501@gmail.com> wrote:
>
> Hey Neal,
>
> Just a quick update: turns out the 1-2 second delays we were seeing were because we had a net.ipv4.tcp_notsent_lowat of 4MB (!!). Setting this to 16KB made BBR perform beautifully on the link, and reduced all queue delays to within the expected RTT variance. I'm still keen on comparing BBR with and without these patches, so will report back shortly with these results.

I am a huge fan of this option, (apple has it too) and certainly the
default is far too high.

I would really love to have an equivalent net.ipv4.tcp_notsent_lowat
for udp sockets as well as a setsockopt. Has that happened yet?


> Cheers,
> Jared.
>
> On Tuesday, March 12, 2019 at 10:50:40 PM UTC-7, Neal Cardwell wrote:
>>
>> Thanks for the report! We'd be interested to hear how it goes.
>>
>> thanks,
>> neal
>>
>> On Tue, Mar 12, 2019 at 10:44 PM Jared Newman <jnewm...@gmail.com> wrote:
>>>
>>> Ah awesome, glad to see the improvements make it into the next kernel! Thanks for the pointers and quick response, Neal.
>>>
>>> We're running TCP BBR on a 2.4GHz mobile ad hoc network and are seeing an excessive outgoing queue build up, leading to application delays of 1-2 seconds on a link that has a BBR-estimated min-RTT of ~15ms. By the sounds of it, feature (2) will be what we want so we'll try applying the patches on top of 18845557fd6f and see how things go.
>>>
>>> Cheers,
>>> Jared.
>>>
>>> On Tuesday, March 12, 2019 at 10:29:08 PM UTC-7, Neal Cardwell wrote:
>>>>
>>>> Hi,
>>>>
>>>> For the patches in  https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY there were two main features:
>>>>
>>>> (1) Higher throughput for wifi and other paths with aggregation
>>>>
>>>> (2) Lower queuing delays by frequently draining excess in-flight data
>>>>
>>>>
>>>> For the patches related to (1), that functionality is already in davem/net-next and torvalds/linux, as of recently, and those patches will be in Linux 5.1. We were waiting until Linux 5.1 is released to announce that on this e-mail list. But since it came up anyway, we may as well mention it. ;-)
>>>>
>>>>
>>>> For the patches related to (2), that functionality is still undergoing testing on YouTube and elsewhere.
>>>>
>>>>
>>>> If you want to apply the original patches from  https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY  then you can apply them on top of the Linux commit:
>>>>
>>>> 18845557fd6f
>>>>
>>>> from March 2018. That's where they were originally generated.
>>>>
>>>>
>>>> best,
>>>>
>>>> neal
>>>>
>>>>
>>>>
>>>> On Tue, Mar 12, 2019 at 10:09 PM Jared Newman <jnewm...@gmail.com> wrote:
>>>>>
>>>>> Hey BBR-dev,
>>>>>
>>>>> I'm trying to apply the patches given in https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY, but am struggling to find what commit of next-net I should apply them on. I tried a couple different tags in https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git but would always get conflicts that I didn't feel comfortable resolving. Does anyone have a suggestion / commit hash to apply them to?
>>>>>
>>>>> Cheers,
>>>>> Jared.
>>>>>
>>>>> --
>>>>> You received this message because you are subscribed to the Google Groups "BBR Development" group.
>>>>> To unsubscribe from this group and stop receiving emails from it, send an email to bbr-dev+u...@googlegroups.com.
>>>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>> --
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>
> --
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-- 

Dave Täht
CTO, TekLibre, LLC
http://www.teklibre.com
Tel: 1-831-205-9740

[Ecn-sane] Fwd: [bbr-dev] Re: Applying BBRv2 patches

[Dave Taht]

---------- Forwarded message ---------
From: 'Neal Cardwell' via BBR Development <bbr-dev@googlegroups.com>
Date: Fri, Mar 15, 2019 at 12:18 PM
Subject: Re: [bbr-dev] Re: Applying BBRv2 patches
To: Jeremy Payne <jp557198@gmail.com>
Cc: BBR Development <bbr-dev@googlegroups.com>


Hi,

The enhancements that we have been calling "BBR v2" are still under
testing, and have not been posted yet. For BBR v2, we sketched out an
overview and some lab test results at IETF 102 (links here). We'll be
giving a quick update about that effort at the ICCRG session at IETF
104 in a few weeks.

For Linux TCP BBR, the most recent upstream patches of interest are
for improving performance with high degrees of aggregation (as in
wifi, cellular, cable modems, LRO/GRO, etc) on low-RTT paths. The
biggest impacts we have seen are cases with wifi links where the
two-way propagation delay is in the range 1-10ms, so that would be a
scenario to start with, for testing. Those patches are discussed here:
  https://groups.google.com/d/msg/bbr-dev/kBZaq98xCC4/5EUi7c3MCgAJ
Keep in mind those patches are not in 5.0.2. They will be in 5.1, or
if you have the option of building custom kernels then you can
cherry-pick them on top of your 5.0.2.

thanks,
neal


On Fri, Mar 15, 2019 at 11:34 AM Jeremy Payne <jp557198@gmail.com> wrote:
>
> Hello,
>
> I've been following developments here, and I'm now considering soaking BBR on one of our production machines.
> Question is, it seems there are some outstanding issues with BBR that may affect network/application response times.
> Before soaking in production, are there any suggested tests I can run in the lab that show performance impacts without the
> BBR2 patches, and then show performance improvements with the BBR2 patches?
>
> Primary use case is live MPEG-DASH/HLS video delivery.
>
> I plan on testing against a kernel that doesnt contain these patches, 4.14.106, and a kernel that looks to contain most of the BBR2 patches, 5.0.2
>
> Thanks!
>
>
> On Wednesday, March 13, 2019 at 12:09:22 AM UTC-5, Jared Newman wrote:
>>
>> Hey BBR-dev,
>>
>> I'm trying to apply the patches given in https://groups.google.com/forum/#!topic/bbr-dev/8pgyOyUavvY, but am struggling to find what commit of next-net I should apply them on. I tried a couple different tags in https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git but would always get conflicts that I didn't feel comfortable resolving. Does anyone have a suggestion / commit hash to apply them to?
>>
>> Cheers,
>> Jared.
>
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Dave Täht
CTO, TekLibre, LLC
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Tel: 1-831-205-9740