sparc: Make sparc64 use scalable lib/iommu-common.c functions
In iperf experiments running linux as the Tx side (TCP client) with 10 threads results in a severe performance drop when TSO is disabled, indicating a weakness in the software that can be avoided by using the scalable IOMMU arena DMA allocation. Baseline numbers before this patch: with default settings (TSO enabled) : 9-9.5 Gbps Disable TSO using ethtool- drops badly: 2-3 Gbps. After this patch, iperf client with 10 threads, can give a throughput of at least 8.5 Gbps, even when TSO is disabled. Signed-off-by:Sowmini Varadhan <sowmini.varadhan@oracle.com> Acked-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
David S. Miller <davem@davemloft.net>
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