[Bug 2071471] Comment bridged from LTC Bugzilla
--- Comment From barbara.mun...@de.ibm.com 2024-08-09 05:10 EDT--- As pointed out before, I consider the verification done. Bug can be closed. -- 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
[Bug 2071471] Comment bridged from LTC Bugzilla
--- Comment From barbara.mun...@de.ibm.com 2024-07-19 02:38 EDT--- I verified that with 6.8.0-40-generic from -proposed the degradation is indeed gone. Thanks a lot! -- 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
[Bug 2071471] Comment bridged from LTC Bugzilla
--- 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
[Bug 2071471] Comment bridged from LTC Bugzilla
--- Comment From niklas.schne...@ibm.com 2024-07-03 05:24 EDT--- Interesting with "make defconfig" on upstream I get ? # CONFIG_IOMMU_DEFAULT_DMA_STRICT is not set CONFIG_IOMMU_DEFAULT_DMA_LAZY=y ? And that works 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 ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 2071471] Comment bridged from LTC Bugzilla
--- Comment From niklas.schne...@ibm.com 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.
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Title:
[UBUNTU 24.04] IOMMU DMA mode changed in kernel config causes massive
throughput degradation for PCI-related network workloads
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