Thanks Kai. Yes, I really want to use Ubuntu kernel to bisect: or at least, I need the option to be able to - because if the problem is coming from the Ubuntu patchset, I could spend weeks bisecting mainline and never find it, whereas if I bisect the Ubuntu tree I'm guaranteed to find it and that one can be mapped back to mainline if needed, whereas we can't go the other way around.
The other critical aspect to having the Ubuntu tree available is that it gives me the Ubuntu 5.0.0-23 build as a sanity check, it case the problem is being caused elsewhere. Remember, this is *wifi* we're talking about: any number of pieces could be to blame, from a power outage resetting something in the router (20/40 coexistence, for example) to physical antennas in multiple devices, and so on. I need a way to validate beyond question that it IS the kernel that's at fault before I go any further with this to avoid risking wasting everybody's time, including yours. :) Anyway, now that I have that info I'll free up a Passport and get things underway. Thanks again. -- 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
