Thread (11 messages) flat view 11 messages, 3 authors, 2017-03-07

[PATCH 1/4] net: thunderx: Fix IOMMU translation faults

From: Sunil Kovvuri <hidden>
Date: 2017-03-06 13:07:17
Also in: lkml, netdev

quoted
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.
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