It was found that 4.15 has a couple more patches missing for NVMe, those patches are required to get to the target number of IOPS.
The commits are: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/nvme/host/pci.c?h=v5.1&id=f9dde187fa921c12a8680089a77595b866e65455 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/nvme/host/pci.c?h=v5.1&id=1ab0cd6966fc4a7e9dfbd7c6eda917ae9c977f42 Would it be possible to pick up those two patches for 4.15. The 1st patch is a clean apply. The 2nd patch needs back porting. We can help, if it is needed for the second patch. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-azure in Ubuntu. https://bugs.launchpad.net/bugs/1819689 Title: [linux-azure] Commit To Improve NVMe Performance Status in linux-azure package in Ubuntu: New Status in linux-azure source package in Xenial: Fix Committed Status in linux-azure source package in Cosmic: Fix Committed Bug description: In bug 1818138, the config option CONFIG_NO_HZ_FULL was requested to be enabled in the linux-azure kernels(currently 4.15 and 4.18) in order to increase NVME disks performance. To achieve the peak IOPs we are seeing in testing, the following commit is also needed: 7ac257b862f2c (“blk-mq: remove the request_list usage”) This commit cleans up unused code in block-mq (mq uses pre-allocated tags to allocate request, not request_list as it's used only in legacy queue). The commit saves a bunch of rcu locks on I/O queuing path, which increases the achievable IOPs seen in testing. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-azure/+bug/1819689/+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
