------- Comment From niklas.schne...@ibm.com 2024-07-03 06:53 EDT------- (In reply to comment #11) > Looks like it's not sufficient to have IOMMU_DEFAULT_DMA_LAZY=y only > in addition IOMMU_DEFAULT_DMA_STRICT=n seems to be needed on top (otherwise > the build failed for me). > (Which I think is not super great upstream, one option should be fine -- > with the two kernel options, there are now two unspecific cases: both n and > both y - anyway ...) > > I did a test build in PPA here: > https://launchpad.net/~fheimes/+archive/ubuntu/lp2071471 > would be great if this can be tried.
I gave this a quick test on a z/VM with a RoCE VF. root@redacted:~# uname -a Linux redacted 6.8.0-38-generic #38~lp2071471-Ubuntu SMP Wed Jul 3 07:09:08 UTC 2024 s390x s390x s390x GNU/Linux root@redacted:~# cat /sys/bus/pci/devices/18d1\:00\:00.0/iommu_group/type DMA-FQ So this uses the DMA Flush Queue mechanism as it should. Thanks! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2071471 Title: [UBUNTU 24.04] IOMMU DMA mode changed in kernel config causes massive throughput degradation for PCI-related network workloads To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/2071471/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
