Upstream resolution: https://lore.kernel.org/linux- pci/20200917140116.ga4...@e121166-lin.cambridge.arm.com/
TL;dr "If that's the case we can go ahead and merge this patch with a reworded commit log [...] Clint, please reword the commit and resend, not sure we can hit v5.10 but we shall try." ** Description changed: - To improve PCI performance on arm64 AWS instances, enable + To improve PCI performance on certain arm64 AWS instance types, enable arch_can_pci_mmap_wc() via the patch: - From: Clint Sbisa <csb...@amazon.com> - Subject: [PATCH] arm64: Enable PCI write-combine resources under sysfs + From: Clint Sbisa <csb...@amazon.com> + Subject: [PATCH] arm64: Enable PCI write-combine resources under sysfs - https://lore.kernel.org/linux- + https://lore.kernel.org/linux- pci/20200831151827.pumm2p54fyj7f...@amazon.com/ + + -------------- + + [Impact] + + * AWS requires PCI-write-combine be enabled for arm64 via this one-line + patch, to effect a significant performance improvement on certain AWS + arm64 instance types. + + * After considerable discussion, upstream indicates that this patch + will be accepted into mainline[0] once additional documentation details + get added to the commit description. + + * Applying this patch to linux-aws affects only AWS arm64 instance + types. + + [Test Case] + + * Has been performance-tested by AWS; smoke-tested by me. + + [Regression Potential] + + * Low. + + [0] https://lore.kernel.org/linux- + pci/20200917140116.ga4...@e121166-lin.cambridge.arm.com/ ** Changed in: linux-aws (Ubuntu) Importance: Medium => High ** Changed in: linux-aws (Ubuntu Bionic) Importance: Medium => High ** Changed in: linux-aws (Ubuntu Groovy) Importance: Medium => High ** Changed in: linux-aws (Ubuntu Focal) Importance: Medium => High -- 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/1893817 Title: aws: enable PCI write-combine for arm64 Status in linux-aws package in Ubuntu: In Progress Status in linux-aws source package in Bionic: Won't Fix Status in linux-aws source package in Focal: Won't Fix Status in linux-aws source package in Groovy: Won't Fix Bug description: To improve PCI performance on certain arm64 AWS instance types, enable arch_can_pci_mmap_wc() via the patch: From: Clint Sbisa <csb...@amazon.com> Subject: [PATCH] arm64: Enable PCI write-combine resources under sysfs https://lore.kernel.org/linux- pci/20200831151827.pumm2p54fyj7f...@amazon.com/ -------------- [Impact] * AWS requires PCI-write-combine be enabled for arm64 via this one- line patch, to effect a significant performance improvement on certain AWS arm64 instance types. * After considerable discussion, upstream indicates that this patch will be accepted into mainline[0] once additional documentation details get added to the commit description. * Applying this patch to linux-aws affects only AWS arm64 instance types. [Test Case] * Has been performance-tested by AWS; smoke-tested by me. [Regression Potential] * Low. [0] https://lore.kernel.org/linux- pci/20200917140116.ga4...@e121166-lin.cambridge.arm.com/ To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-aws/+bug/1893817/+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
