[Bug 1536837] Re: Severe performance regression in Infiniband or IPoIB

The task "linux (Ubuntu)" has expired because it has had no new comments or updates for more than three years. If this issue is still present in an Ubuntu LTS kernel still under active support, please reopen the bug and provide updated details. If this issue was reported against an Ubuntu kernel no longer under active support but the issue still exists in a currently supported Ubuntu kernel, please open a new bug against that kernel version and provide the updated details, with a reference link to the original bug. This action was performed by an automated process maintained by the Ubuntu Kernel Team. ** Tags added: kernel-autoclosed kernel-autoclosed-expired ** Changed in: linux (Ubuntu) Status: Triaged => Expired -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/1536837 Title: Severe performance regression in Infiniband or IPoIB Status in Linux: Unknown Status in linux package in Ubuntu: Expired Bug description: When upgrading to the latest 4.4 test kernel from mainline development, all IPoIB links showed a severe performance regression as compared with kernel 4.2. The bandwidth of each link dropped from around 3Gbps to around 3Mbps (3 orders of magnitude worse!); reverting to the 4.2 kernel immediately fixed this problem. The 4.3 kernel from Debian does not appear to suffer from this regression. The regression shows up on both IB ports of the Mellanox MT25208 controller. Other hardware has not been tested. To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1536837/+subscriptions