Messages in this thread |  | | Subject | Re: [bug report] iommu_dma_unmap_sg() is very slow then running IO from remote numa node | From | John Garry <> | Date | Mon, 26 Jul 2021 08:51:32 +0100 |
| |
On 23/07/2021 11:21, Ming Lei wrote: >> Thanks, I was also going to suggest the latter, since it's what >> arm_smmu_cmdq_issue_cmdlist() does with IRQs masked that should be most >> indicative of where the slowness most likely stems from. > The improvement from 'iommu.strict=0' is very small: >
Have you tried turning off the IOMMU to ensure that this is really just an IOMMU problem?
You can try setting CONFIG_ARM_SMMU_V3=n in the defconfig or passing cmdline param iommu.passthrough=1 to bypass the the SMMU (equivalent to disabling for kernel drivers).
Thanks, John
|  |