** Also affects: linux-azure-4.15 (Ubuntu) Importance: Undecided Status: New
** Changed in: linux-azure-4.15 (Ubuntu Bionic) Status: New => In Progress ** Changed in: linux-azure-4.15 (Ubuntu Bionic) Importance: Undecided => Medium ** Changed in: linux-azure-4.15 (Ubuntu Bionic) Assignee: (unassigned) => Tim Gardner (timg-tpi) ** Description changed: [SRU Justification] + + SF#00308239 [Impact] A soft lockup is happening to Azure cloud customers due to a bug in netvsc_poll. Ubuntu 4.15.0-1103 has CONFIG_NET_POLL_CONTROLLER=y in kernel config file, there is a bug in netvsc that may cause CPU lockup with POLL_CONTROLLER. This bug has been fixed by the following patch: commit 2a7f8c3b1d3feedee3aa319ac220cbde3725b5d5 ("hv_netvsc: remove ndo_poll_controller") This commit is in mainline as of 4.20-rc1. Microsoft would like to request this patch in 4.15 based Azure kernels. [Test Plan] Run high stress network traffic on an Azure instance. [Where problems could occur] There could be a decrease in performance or dropped packets due to NAPI not being able to keep up. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1924314 Title: netvsc may cause CPU lockup To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1924314/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs