** Changed in: linux (Ubuntu Bionic) Status: In Progress => Fix Committed
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1777727 Title: hisi_sas: improve read performance by pre-allocating slot DMA buffers Status in linux package in Ubuntu: In Progress Status in linux source package in Bionic: Fix Committed Bug description: [Impact] Read performance is ~9% slower than it could be, as measured by the iozone3 benchmark. [Test Case] iozone -a I suggest collecting 5 runs of this, with and without the patch, and generating a report using: https://github.com/Rovanion/iozone-results-comparator/wiki/Overview [Fix] Apply a patch queued in the scsi tree that pre-allocates DMA slot buffers. [Regression Risk] As called out in the commit log, the trade-off here is static memory usage, which could grow by ~17MB. However, as also noted, this method actually uses *less* memory than the baseline when all slots are allocated (32MB). (Ubuntu uses a 4K kernel). The required fixes are localized to the hisi_sas driver. This driver is only used by two platforms supported by Ubuntu: HiSilicon D05 and HiSilicon D06. We will directly verify these fixes on those platforms. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1777727/+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