>> >> We are seeing a 0.75Mpps drop with IP forwarding rate due to that. >> Hence I have restricted calling DMA interfaces to only when IOMMU is enabled. > > What's 0.07Mpps as a percentage of baseline? On a correctly configured > coherent arm64 system, in the absence of an IOMMU, dma_map_*() is > essentially just virt_to_phys() behind a function call or two, so I'd be > interested to know where any non-trivial overhead might be coming from.
It's a 5% drop and yes device is configured as coherent. And the drop is due to additional function calls. Thanks, Sunil.
