From: David S. Miller Date: Thu, 11 Feb 2016 13:55:42 +0000 (-0500) Subject: Merge branch 'gso-checksums' X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e7e9956d8fc3c92e797e7334f2aee31dd9c623f3;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git Merge branch 'gso-checksums' Alexander Duyck says: ==================== Add GSO support for outer checksum w/ inner checksum offloads This patch series updates the existing segmentation offload code for tunnels to make better use of existing and updated GSO checksum computation. This is done primarily through two mechanisms. First we maintain a separate checksum in the GSO context block of the sk_buff. This allows us to maintain two checksum values, one offloaded with values stored in csum_start and csum_offset, and one computed and tracked in SKB_GSO_CB(skb)->csum. By maintaining these two values we are able to take advantage of the same sort of math used in local checksum offload so that we can provide both inner and outer checksums with minimal overhead. Below is the performance for a netperf session between an ixgbe PF and VF on the same host but in different namespaces. As can be seen a significant gain in performance can be had from allowing the use of Tx checksum offload on the inner headers while performing a software offload on the outer header computation: Recv Send Send Utilization Service Demand Socket Socket Message Elapsed Send Recv Send Recv Size Size Size Time Throughput local remote local remote bytes bytes bytes secs. 10^6bits/s % S % U us/KB us/KB Before: 87380 16384 16384 10.00 12844.38 9.30 -1.00 0.712 -1.00 After: 87380 16384 16384 10.00 13216.63 6.78 -1.00 0.504 -1.000 Changes from v1: * Dropped use of CHECKSUM_UNNECESSARY for remote checksum offload * Left encap_hdr_csum as it will likely be needed in future for SCTP GSO * Broke the changes out over many more patches * Updated GRE segmentation to more closely match UDP tunnel segmentation ==================== Signed-off-by: David S. Miller --- e7e9956d8fc3c92e797e7334f2aee31dd9c623f3