On Fri, May 12, 2017 at 9:06 AM, Jeff Hugo <[email protected]> wrote: > Just FYI, it will likely take me a few days to get to this.
Thanks Jeff, no problem. > > Jeffrey Hugo > Senior Engineer > Qualcomm Datacenter Technologies, Inc. > 1-303-247-5002 > > From: Manoj Iyer [mailto:[email protected]] > Sent: Thursday, May 11, 2017 9:23 PM > To: Jeff Hugo <[email protected]>; [email protected] > Cc: Nate Watterson <[email protected]>; Timur Tabi > <[email protected]> > Subject: [Bug #1688158] Please help test kernel for > iommu.passthrough=0/1 > > Jeff, > > I have back-ported patches to address "Support SMMU passthrough using > the default domain". This adds a new kernel command line option > iommu.passthrough=0/1 to Configure DMA to bypass the IOMMU for ARM64. > http://bugs.launchpad.net/bugs/1688158 > > 0 - Use IOMMU translation for DMA. > 1 - Bypass the IOMMU for DMA. > > The test case recommended by Nate using 'fio' is: > > $ sudo apt update ; sudo apt install fio > > $ sudo fio --name=global --readonly --group_reporting --direct=1 > --ioengine=libaio --rw=read --eta-newline=1s --size=1T > --blocksize=512k --iodepth=32 --numjobs=1 --runtime=10s > --name=nvme_0 --filename=/dev/nvme0n1 > > You can find the kernel and the instructions to install the kernel in > the Centriq test PPA: > https://launchpad.net/~centriq-team/+archive/ubuntu/test/ > > Nate and I have gone back and forth on testing these patches and > finally came down to having this test run on an NVME device. > Unfortunately I cant seem to find any nvme HW at this time, we would > need to order these drive and could take time. > > Could you please test the kernel using the test case mentioned above > and reply back to this email with test case out put for both cases. > iommu.passthrough=0 and iommu.passthrough=1. We should see better > performance (iops may be) with IOMMU bypassed for DMA (ie > iommu.passthrough=1). > > The bug is cced on this email, so if you replay with a summary output > in both cases it will be automatically recorded in the bug. Once I > get your test results I will be able to make a case for SRUing these > patches. > > Thanks a ton > Manoj Iyer -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1688158 Title: [SRU][Zesty] Support SMMU passthrough using the default domain To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1688158/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
