From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jithu Joseph Date: Mon, 22 Feb 2021 01:09:27 -0800 Subject: [Intel-wired-lan] [PATCH v4 0/9] igc: Add support for AF_XDP zero-copy Message-ID: <20210222090936.6768-1-jithu.joseph@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: Hi all, This is the fourth version of this series which adds AF_XDP zero-copy support to igc driver. The main changes from v3 are: - Renamed igc_xdp_run_prog() to __igc_xdp_run_prog() - Reworded commit message for 2nd patch in this series as suggested in the review - igc_clean_rx_irq_zc() - Assigned ring->next_to_clean to local variable for performance reasons as suggested in review comment - igc_xdp_xmit_zc() - Assigned ring->next_to_use to local variable and replaced work_done conditional variable as per review comment - Added Maciej Fijalkowski's reviewed by tags Known issues (from v3): When an XDP application is running in Tx-Only mode with Zero-Copy enabled, it is not expected to add the frames to the fill-queue. I have noticed the following two issues in this scenario: - If XDP_USE_NEED_WAKEUP flag is not set by application, igc_poll() will go into infinite loop because the buffer allocation resulting in igc_clean_rx_irq_zc() indicating that all work is not done and NAPI should keep polling. This does not occur if XDP_USE_NEED_WAKEUP flag is set. - Since there are no buffers allocated by userspace for the fill queue, there is no memory allocated for the NIC to copy the data to. If the packet received is destined to the hardware queue where XDP application is running, no packets are received even on other queues. Both these issues can be mitigated by adding a few frames to the fill queue. The second issue can also be mitigated by making sure no packets are being received on the hardware queue where Rx is running. v3 is here: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20210209024243.23406-1-vedang.patel at intel.com/ v2 is here: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201223203705.78705-1-andre.guedes at intel.com/ v1 is here: https://patchwork.ozlabs.org/project/intel-wired-lan/cover/20201217202415.77891-1-andre.guedes at intel.com/ Andre Guedes (9): igc: Move igc_xdp_is_enabled() igc: Refactor __igc_xdp_run_prog() igc: Refactor igc_clean_rx_ring() igc: Refactor XDP rxq info registration igc: Introduce TX/RX stats helpers igc: Introduce igc_unmap_tx_buffer() helper igc: Replace IGC_TX_FLAGS_XDP flag by an enum igc: Enable RX via AF_XDP zero-copy igc: Enable TX via AF_XDP zero-copy drivers/net/ethernet/intel/igc/igc.h | 33 +- drivers/net/ethernet/intel/igc/igc_base.h | 2 + drivers/net/ethernet/intel/igc/igc_main.c | 651 ++++++++++++++++++---- drivers/net/ethernet/intel/igc/igc_xdp.c | 107 +++- drivers/net/ethernet/intel/igc/igc_xdp.h | 8 +- 5 files changed, 674 insertions(+), 127 deletions(-) -- 2.17.1