------- Comment From [email protected] 2024-07-01 04:49 EDT------- For reference the the CONFIG_DMA_DEFAULT_DMA setting is relevant to s390 only since upstream commit c76c067e488c ("s390/pci: Use dma-iommu layer").
This commit also includes the following hunk to default to CONFIG_DEFAULT_DMA_LAZY on s390x. Though I guess this wouldn't overwrite a pre-existing config value: diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index cd6727898b11..3199fd54b462 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -91,7 +91,7 @@ config IOMMU_DEBUGFS choice prompt "IOMMU default domain type" depends on IOMMU_API - default IOMMU_DEFAULT_DMA_LAZY if X86 || IA64 + default IOMMU_DEFAULT_DMA_LAZY if X86 || IA64 || S390 default IOMMU_DEFAULT_DMA_STRICT help Choose the type of IOMMU domain used to manage DMA API usage by The line has been modified since to drop IA64 but does contain S390 on current upstream as well. -- 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 [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
