From: Eric Dumazet <eric.dumazet@gmail.com>
To: Johannes Berg <johannes@sipsolutions.net>,
Krishna Chaitanya <chaitanya.mgit@gmail.com>
Cc: "Neal Cardwell" <ncardwell@google.com>,
"Toke Høiland-Jørgensen" <toke@redhat.com>,
linux-wireless <linux-wireless@vger.kernel.org>,
Netdev <netdev@vger.kernel.org>
Subject: Re: debugging TCP stalls on high-speed wifi
Date: Fri, 24 Jan 2020 15:49:15 -0800 [thread overview]
Message-ID: <9f984cda-2209-fa07-569e-2555ef2aa78d@gmail.com> (raw)
In-Reply-To: <ef348261c1edd9892b09ed017a59be23aa2be688.camel@sipsolutions.net>
On 1/24/20 2:34 AM, Johannes Berg wrote:
> On Fri, 2019-12-13 at 14:40 +0530, Krishna Chaitanya wrote:
>>
>> Maybe try 'reno' instead of 'cubic' to see if congestion control is
>> being too careful?
>
> I played around with this a bit now, but apart from a few outliers, the
> congestion control algorithm doesn't have much effect. The outliers are
>
> * vegas with ~120 Mbps
> * nv with ~300 Mbps
> * cdg with ~600 Mbps
>
> All the others from my list (reno cubic bbr bic cdg dctcp highspeed htcp
> hybla illinois lp nv scalable vegas veno westwood yeah) are within 50
> Mbps or so from each other (around 1.45Gbps).
>
When the stalls happens, what is causing TCP to resume the xmit ?
Some tcpdump traces could help.
(-s 100 to only capture headers)
next prev parent reply other threads:[~2020-01-24 23:49 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-12 14:50 debugging TCP stalls on high-speed wifi Johannes Berg
2019-12-12 15:11 ` Neal Cardwell
2019-12-12 15:47 ` Johannes Berg
2019-12-12 18:11 ` Eric Dumazet
2019-12-12 21:11 ` Johannes Berg
2019-12-12 21:29 ` Ben Greear
2019-12-12 21:46 ` Johannes Berg
2019-12-12 21:58 ` Ben Greear
2019-12-12 21:50 ` Eric Dumazet
2019-12-12 21:53 ` Johannes Berg
2019-12-12 23:42 ` Dave Taht
2019-12-13 0:59 ` [Make-wifi-fast] " Simon Barber
2019-12-13 1:46 ` Eric Dumazet
2019-12-13 1:57 ` Simon Barber
2019-12-13 4:42 ` Dave Taht
2019-12-13 8:08 ` Johannes Berg
2019-12-13 9:10 ` Krishna Chaitanya
2020-01-24 10:34 ` Johannes Berg
2020-01-24 23:49 ` Eric Dumazet [this message]
2019-12-13 4:15 ` Justin Capella
2019-12-13 7:43 ` Johannes Berg
-- strict thread matches above, loose matches on Subject: below --
2019-12-16 18:14 Simon Barber
2019-12-16 19:20 ` Eric Dumazet
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