Arch Linux

loqs

Member

Registered: 2014-03-06

Posts: 17,321

Re: [SOLVED][Bug]Kernel 4.15 - Default TCP Congestion BBR - Slow network

Might want to consider reporting this upstream to the kernel developers.

jonno2002

Member

Registered: 2016-11-21

Posts: 684

Re: [SOLVED][Bug]Kernel 4.15 - Default TCP Congestion BBR - Slow network

https://bugs.archlinux.org/task/57476  says the bug is fixed in 4.15.3 but it is not, had to change the bbr to cubic again and all fixed

seth

Member

Registered: 2012-09-03

Posts: 51,017

Re: [SOLVED][Bug]Kernel 4.15 - Default TCP Congestion BBR - Slow network

4.15.3-2

pacman -Qi linux

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extr

Member

Registered: 2016-09-23

Posts: 4

Re: [SOLVED][Bug]Kernel 4.15 - Default TCP Congestion BBR - Slow network

I'm having a similarly presenting issue with networking using a Qualcomm Atheros QCA6174 card in an XPS 13. I have not had time to test different kernels yet but it just appeared very recently so I'm guessing 4.15.2 or higher is the culprit. Running 4.15.2-3 now and still having issues (switching to cubic doesn't seem to help). Seeing intermittent slowdown and dropped packets, sometimes it seems like it can't resolve anything for about 20-30 seconds and then fixes itself. I am not sure it is the same issue, I can make a separate thread if needed but the timing seemed very coincidental.

Ping log from a particularly bad stretch:

64 bytes from 8.8.8.8: icmp_seq=124 ttl=58 time=24.4 ms
64 bytes from 8.8.8.8: icmp_seq=125 ttl=58 time=23.7 ms
64 bytes from 8.8.8.8: icmp_seq=128 ttl=58 time=151 ms
64 bytes from 8.8.8.8: icmp_seq=132 ttl=58 time=121 ms
64 bytes from 8.8.8.8: icmp_seq=133 ttl=58 time=31.9 ms
64 bytes from 8.8.8.8: icmp_seq=138 ttl=58 time=121 ms
64 bytes from 8.8.8.8: icmp_seq=139 ttl=58 time=21.4 ms
64 bytes from 8.8.8.8: icmp_seq=140 ttl=58 time=27.4 ms
64 bytes from 8.8.8.8: icmp_seq=152 ttl=58 time=140 ms
64 bytes from 8.8.8.8: icmp_seq=153 ttl=58 time=35.4 ms
64 bytes from 8.8.8.8: icmp_seq=157 ttl=58 time=141 ms
^C
--- 8.8.8.8 ping statistics ---
159 packets transmitted, 34 received, 78% packet loss, time 161271ms
rtt min/avg/max/mdev = 21.291/95.537/151.259/51.461 ms

jonno2002

Member

Registered: 2016-11-21

Posts: 684

Re: [SOLVED][Bug]Kernel 4.15 - Default TCP Congestion BBR - Slow network

4.15.3-2 does fix it, i must have updated before my mirror got the update