I think I found the kernel which adds the first downgrade in performance between 6.5.0-45 and 6.8.0-38. I tried the same downloads with kernels on mainline repo:
6.7.6-060706-generic = 2025-04-22 20:17:13 (323 MB/s) 6.7.7-060707-generic = 2025-04-22 20:37:24 (229 MB/s) -- 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/2107347 Title: Severe Network Performance Regression with BCM57800/BCM57810 on Kernel 6.8.0-40 through 6.12.16 Status in linux package in Ubuntu: Confirmed Status in linux source package in Jammy: In Progress Bug description: Significant network performance degradation when using Broadcom BCM57800/BCM57810 (bnx2x) NICs with jumbo frames on Ubuntu Jammy with kernels starting from 6.8.0-38, with the issue becoming severe and rendering the system unusable from 6.8.0-40 onwards. There is a similar report here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2098961 However, the proposed fix in that report does not resolve the issue for BCM57800 using the bnx2x driver. Environment: OS: Ubuntu 22.04(Jammy Jellyfish) Current HWE Kernel: 6.8.0-57.59~22.04.1 NIC: Broadcom BCM57800 / BCM57810 Driver: bnx2x Observed Behavior: Noticeable network degradation begins in kernel 6.8.0-38 Becomes unusable in kernel 6.8.0-40 and beyond Still reproducible in latest HWE kernel 6.8.0-57 Lowering the MTU to 1500 increases performance Expected Behavior: Stable and performant network performance as seen in previous kernel versions Additional Notes: As mentioned in LP#2098961, the issue appears to be fixed in kernel 6.12.17[0]. Request that this fix be backported or that further investigation be made into kernel regressions affecting bnx2x on these NICs. [0] https://kernel.ubuntu.com/mainline/v6.12.17/ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2107347/+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
