Okay - the 18.04.3 release I tested in September, which was fine, has 5.0.0-23.
-29 is broken, as mentioned above. That's a pretty narrow window to work with. I'd prefer it if someone from Canonical took it from here. (Heck, there are probably few enough commits to that driver in that timeframe that I could find the bad one more easily just by browsing the source than getting that machine to build it). Since it's the HWE stack that's broken, I could still install 18.04 from the image I have and switch back to the original Bionic kernel series, though it's anybody's guess if the same regression was merged into 4.15 again as well. Having to do a fresh install sucks pretty hard, but I'd at least be able to pin the last unbroken kernel, whereas on 19.10 there aren't any working ones in the repos at all (AFAIK) so I'm basically screwed until a fix makes its way through the system or I brute-force an older one onto it. I'm still trying to decide if I really want to go down that road or not. I found https://people.canonical.com/~kernel/info/kernel-version-map.html , but it's basically useless. All the 4.15 kernels from the working -32 through the 7 months of buggy ones and out the other side to -55 when it was fixed are all just "4.15.18 mainline". Maybe I'm missing something here, but without the tree that you guys are *actually building from* I don't see how me bisecting mainline is going to achieve anything. If that page is accurate it has nothing to do with mainline at all and the bug only exists in the Ubuntu tree in the first place, neh? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1847892 Title: large performance regression (~30-40%) in wifi with 19.10 / 5.3 kernel Status in linux package in Ubuntu: Confirmed Bug description: Probably relevant: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1795116 Card is an RTL8723BE. On 16.04 with the HWE stack, after 1795116 was fixed performance was a stable 75-80Mb/s. Linux 4.15.0-55-generic #60~16.04.2-Ubuntu SMP Thu Jul 4 09:03:09 UTC 2019 x86_64 Fri 26-Jul-19 12:28 sent 459,277,171 bytes received 35 bytes 9,278,327.39 bytes/sec Linux 4.15.0-55-generic #60~16.04.2-Ubuntu SMP Thu Jul 4 09:03:09 UTC 2019 x86_64 Sat 27-Jul-19 01:23 sent 459,277,171 bytes received 35 bytes 10,320,836.09 bytes/sec On 18.04, performance was still a stable 75-80Mb/s. After updating to 19.10, performance is typically ~50Mb/s, or about a 37% regression. $ iwconfig wlan0 wlan0 IEEE 802.11 ESSID:"**" Mode:Managed Frequency:2.442 GHz Access Point: 4C:60:DE:FB:A8:AB Bit Rate=150 Mb/s Tx-Power=20 dBm Retry short limit:7 RTS thr=2347 B Fragment thr:off Power Management:on Link Quality=59/70 Signal level=-51 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:315 Missed beacon:0 $ ./wifibench.sh Linux 5.3.0-13-generic #14-Ubuntu SMP Tue Sep 24 02:46:08 UTC 2019 x86_64 Sat 12-Oct-19 20:30 sent 459,277,171 bytes received 35 bytes 5,566,996.44 bytes/sec $ iwconfig wlan0 wlan0 IEEE 802.11 ESSID:"**" Mode:Managed Frequency:2.442 GHz Access Point: 4C:60:DE:FB:A8:AB Bit Rate=150 Mb/s Tx-Power=20 dBm Retry short limit:7 RTS thr=2347 B Fragment thr:off Power Management:on Link Quality=68/70 Signal level=-42 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:315 Missed beacon:0 So no corrupted packets or etc during that transfer. $ ifconfig wlan0 wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.1.33 netmask 255.255.255.0 broadcast 192.168.1.255 ether dc:85:de:e4:17:a3 txqueuelen 1000 (Ethernet) RX packets 56608204 bytes 79066485957 (79.0 GB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 21634510 bytes 8726094217 (8.7 GB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 No issues of any kind in the week that it's been up. Just terrible performance. I'm painfully aware of all the module's parameters etc, and have tried them all, with no change in the results outside of typical wifi variance. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1847892/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp