Public bug reported: SRU Justification:
[Impact] In Ubuntu AMIs for x86 and Graviton based EC2 instances, the standard Ubuntu AMI comes without IRQ moderation enabled for ENA, which for our latest generation instances with networking heavy workloads is up to a 25% performance regression (i.e. NGINX in a load-balancing configuration). [Fix] The mainline Linux kernel will now support IRQ moderation by default for ENA in the 6.9 kernel release via this patch: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/drivers/net/ethernet/amazon/ena?id=50d7a2660579889fba28b7e4543d4ce85aa2311b [Test Plan] AWS tested [Where problems could occur] By enabling adaptive coalescing, the default interrupt behaviour will by changed to be more adaptive, which shows improvements on heavy network workloads, but my change the behaviour and performance on other network workloads differently. Rather than handling the interrupts based off of a fixed amount of time elapsed, it will change to an adaptive based approach. There should be no negative impact on light workloads, and a positive impact on heavy work loads. If there is an impact though, this option can be disabled via the ethtool command. [Other Info] SF: 00380449 ** Affects: linux-aws (Ubuntu) Importance: Undecided Assignee: Philip Cox (philcox) Status: In Progress ** Affects: linux-aws (Ubuntu Focal) Importance: Undecided Status: In Progress ** Affects: linux-aws (Ubuntu Jammy) Importance: Undecided Status: In Progress ** Affects: linux-aws (Ubuntu Mantic) Importance: Undecided Status: In Progress ** Affects: linux-aws (Ubuntu Noble) Importance: Undecided Assignee: Philip Cox (philcox) Status: In Progress ** Also affects: linux-aws (Ubuntu Jammy) Importance: Undecided Status: New ** Also affects: linux-aws (Ubuntu Noble) Importance: Undecided Assignee: Philip Cox (philcox) Status: New ** Also affects: linux-aws (Ubuntu Mantic) Importance: Undecided Status: New ** Also affects: linux-aws (Ubuntu Focal) Importance: Undecided Status: New ** Changed in: linux-aws (Ubuntu Jammy) Status: New => In Progress ** Changed in: linux-aws (Ubuntu Mantic) Status: New => In Progress ** Changed in: linux-aws (Ubuntu Focal) Status: New => In Progress ** Changed in: linux-aws (Ubuntu Noble) Status: New => In Progress -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-aws in Ubuntu. https://bugs.launchpad.net/bugs/2056475 Title: aws: Backport latest ENA driver in upstream Linux to enable IRQ moderation Status in linux-aws package in Ubuntu: In Progress Status in linux-aws source package in Focal: In Progress Status in linux-aws source package in Jammy: In Progress Status in linux-aws source package in Mantic: In Progress Status in linux-aws source package in Noble: In Progress Bug description: SRU Justification: [Impact] In Ubuntu AMIs for x86 and Graviton based EC2 instances, the standard Ubuntu AMI comes without IRQ moderation enabled for ENA, which for our latest generation instances with networking heavy workloads is up to a 25% performance regression (i.e. NGINX in a load-balancing configuration). [Fix] The mainline Linux kernel will now support IRQ moderation by default for ENA in the 6.9 kernel release via this patch: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/drivers/net/ethernet/amazon/ena?id=50d7a2660579889fba28b7e4543d4ce85aa2311b [Test Plan] AWS tested [Where problems could occur] By enabling adaptive coalescing, the default interrupt behaviour will by changed to be more adaptive, which shows improvements on heavy network workloads, but my change the behaviour and performance on other network workloads differently. Rather than handling the interrupts based off of a fixed amount of time elapsed, it will change to an adaptive based approach. There should be no negative impact on light workloads, and a positive impact on heavy work loads. If there is an impact though, this option can be disabled via the ethtool command. [Other Info] SF: 00380449 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/2056475/+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
