Merge branch 'rmnet-tx-pkt-aggregation'
Daniele Palmas says: ==================== net: add tx packets aggregation to ethtool and rmnet Hello maintainers and all, this patchset implements tx qmap packets aggregation in rmnet and generic ethtool support for that. Some low-cat Thread-x based modems are not capable of properly reaching the maximum allowed throughput both in tx and rx during a bidirectional test if tx packets aggregation is not enabled. I verified this problem with rmnet + qmi_wwan by using a MDM9207 Cat. 4 based modem (50Mbps/150Mbps max throughput). What is actually happening is pictured at https://drive.google.com/file/d/1gSbozrtd9h0X63i6vdkNpN68d-9sg8f9/view Testing with iperf TCP, when rx and tx flows are tested singularly there's no issue in tx and minor issues in rx (not able to reach max throughput). When there are concurrent tx and rx flows, tx throughput has an huge drop. rx a minor one, but still present. The same scenario with tx aggregation enabled is pictured at https://drive.google.com/file/d/1jcVIKNZD7K3lHtwKE5W02mpaloudYYih/view showing a regular graph. This issue does not happen with high-cat modems (e.g. SDX20), or at least it does not happen at the throughputs I'm able to test currently: maybe the same could happen when moving close to the maximum rates supported by those modems. Anyway, having the tx aggregation enabled should not hurt. The first attempt to solve this issue was in qmi_wwan qmap implementation, see the discussion at https://lore.kernel.org/netdev/20221019132503.6783-1-dnlplm@gmail.com/ However, it turned out that rmnet was a better candidate for the implementation. Moreover, Greg and Jakub suggested also to use ethtool for the configuration: not sure if I got their advice right, but this patchset add also generic ethtool support for tx aggregation. The patches have been tested mainly against an MDM9207 based modem through USB and SDX55 through PCI (MHI). v2 should address the comments highlighted in the review: the implementation is still in rmnet, due to Subash's request of keeping tx aggregation there. v3 fixes ethtool-netlink.rst content out of table bounds and a W=1 build warning for patch 2. v4 solves a race related to egress_agg_params. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Showing
Please register or sign in to comment