Significant level of retransmissions affecting WiFi performance. Tested with a few versions of iwlwifi firmware: iwlwifi-cc-a0-{46,48,50,53,55}.ucode and 9260-th-b0-jf-b0-46.ucode. First observed with kernel 5.9.2-300. Problem does not exist in any 5.8 kernel. Tested only with 5 GHz WLAN Intel cards AX200, AC9260 and 8260. Can be observed by high number of retransmissions while testing connection with iperf3: Connecting to host host, port 5201 [ 5] local 10.0.0.50 port 54120 connected to 10.0.0.10 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 55.5 MBytes 466 Mbits/sec 0 1.77 MBytes [ 5] 1.00-2.00 sec 3.75 MBytes 31.5 Mbits/sec 1342 19.8 KBytes [ 5] 2.00-3.00 sec 26.2 MBytes 220 Mbits/sec 7 201 KBytes [ 5] 3.00-4.00 sec 8.75 MBytes 73.4 Mbits/sec 595 15.6 KBytes [ 5] 4.00-5.00 sec 23.8 MBytes 199 Mbits/sec 14 192 KBytes [ 5] 5.00-6.00 sec 11.2 MBytes 94.4 Mbits/sec 573 2.83 KBytes [ 5] 6.00-7.00 sec 21.2 MBytes 178 Mbits/sec 47 178 KBytes [ 5] 7.00-8.00 sec 12.5 MBytes 105 Mbits/sec 557 18.4 KBytes [ 5] 8.00-9.00 sec 21.2 MBytes 178 Mbits/sec 44 177 KBytes [ 5] 9.00-10.00 sec 15.0 MBytes 126 Mbits/sec 535 18.4 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 199 MBytes 167 Mbits/sec 3714 sender [ 5] 0.00-10.00 sec 196 MBytes 164 Mbits/sec receiver iperf Done.
I have the same problem, kernel 5.9.16, ax200 upload speed only 10MB/S kernel 5.8.18, ax200 upload speed can 80MB/S
Tested again with kernel-5.10.5-200.fc33. Problem is still there: [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 7.99 MBytes 67.0 Mbits/sec 401 28.3 KBytes [ 5] 1.00-2.00 sec 6.52 MBytes 54.7 Mbits/sec 301 18.4 KBytes [ 5] 2.00-3.00 sec 6.84 MBytes 57.3 Mbits/sec 265 17.0 KBytes [ 5] 3.00-4.00 sec 6.09 MBytes 51.1 Mbits/sec 279 14.1 KBytes [ 5] 4.00-5.00 sec 5.53 MBytes 46.4 Mbits/sec 246 18.4 KBytes [ 5] 5.00-6.00 sec 6.90 MBytes 57.9 Mbits/sec 249 18.4 KBytes [ 5] 6.00-7.00 sec 5.65 MBytes 47.4 Mbits/sec 293 15.6 KBytes [ 5] 7.00-8.00 sec 6.40 MBytes 53.7 Mbits/sec 270 21.2 KBytes [ 5] 8.00-9.00 sec 6.34 MBytes 53.2 Mbits/sec 293 19.8 KBytes [ 5] 9.00-10.00 sec 6.28 MBytes 52.7 Mbits/sec 317 18.4 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 64.5 MBytes 54.1 Mbits/sec 2914 sender [ 5] 0.00-10.00 sec 63.7 MBytes 53.4 Mbits/sec receiver
I have this issue as well. 5.8.18 no issues Anything between kernel 5.9-5.11 wifi upload is nerfed.
Can you try this patch https://lore.kernel.org/r/CANn89iJWG2n1s3j7EdpwkQQv-9dOY02V+FGYHAWguO4JiqWuJA@mail.gmail.com
(In reply to Johannes Berg from comment #4) > Can you try this patch > > https://lore.kernel.org/r/CANn89iJWG2n1s3j7EdpwkQQv- > 9dOY02V+FGYHAWguO4JiqWuJA@mail.gmail.com tried the patch in https://bugzilla.kernel.org/show_bug.cgi?id=209913
(In reply to Johannes Berg from comment #4) > Can you try this patch > > https://lore.kernel.org/r/CANn89iJWG2n1s3j7EdpwkQQv- > 9dOY02V+FGYHAWguO4JiqWuJA@mail.gmail.com disabling tso offload resolves the issue, for now I wrote a script that disables it on boot
The patch is now on its way to mainline/stable: https://patchwork.kernel.org/project/netdevbpf/patch/20210125150949.619309-1-eric.dumazet@gmail.com/
*** This bug has been marked as a duplicate of bug 209913 ***