On Wed, Dec 11, 2024 at 09:45:32PM +0800, Song Yoong Siang wrote: > Improve XDP_SETUP_PROG process by avoiding unnecessary link down event. > > This patch is tested by using ip link set xdpdrv command to attach a simple > XDP program which always return XDP_PASS. > > Before this patch, attaching xdp program will cause ptp4l to lost sync for > few seconds, as shown in ptp4l log below: > ptp4l[198.082]: rms 4 max 8 freq +906 +/- 2 delay 12 +/- 0 > ptp4l[199.082]: rms 3 max 4 freq +906 +/- 3 delay 12 +/- 0 > ptp4l[199.536]: port 1 (enp2s0): link down > ptp4l[199.536]: port 1 (enp2s0): SLAVE to FAULTY on FAULT_DETECTED (FT_UNSPECIFIED) > ptp4l[199.600]: selected local clock 22abbc.fffe.bb1234 as best master > ptp4l[199.600]: port 1 (enp2s0): assuming the grand master role > ptp4l[199.600]: port 1 (enp2s0): master state recommended in slave only mode > ptp4l[199.600]: port 1 (enp2s0): defaultDS.priority1 probably misconfigured > ptp4l[202.266]: port 1 (enp2s0): link up > ptp4l[202.300]: port 1 (enp2s0): FAULTY to LISTENING on INIT_COMPLETE > ptp4l[205.558]: port 1 (enp2s0): new foreign master 44abbc.fffe.bb2144-1 > ptp4l[207.558]: selected best master clock 44abbc.fffe.bb2144 > ptp4l[207.559]: port 1 (enp2s0): LISTENING to UNCALIBRATED on RS_SLAVE > ptp4l[208.308]: port 1 (enp2s0): UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED > ptp4l[208.933]: rms 742 max 1303 freq -195 +/- 682 delay 12 +/- 0 > ptp4l[209.933]: rms 178 max 274 freq +387 +/- 243 delay 12 +/- 0 > > After this patch, attaching xdp program no longer cause ptp4l to lost sync, > as shown on ptp4l log below: > ptp4l[201.183]: rms 1 max 3 freq +959 +/- 1 delay 8 +/- 0 > ptp4l[202.183]: rms 1 max 3 freq +961 +/- 2 delay 8 +/- 0 > ptp4l[203.183]: rms 2 max 3 freq +958 +/- 2 delay 8 +/- 0 > ptp4l[204.183]: rms 3 max 5 freq +961 +/- 3 delay 8 +/- 0 > ptp4l[205.183]: rms 2 max 4 freq +964 +/- 3 delay 8 +/- 0 > > Besides, before this patch, attaching xdp program will cause flood ping to > loss 10 packets, as shown in ping statistics below: > --- 169.254.1.2 ping statistics --- > 100000 packets transmitted, 99990 received, +6 errors, 0.01% packet loss, time 34001ms > rtt min/avg/max/mdev = 0.028/0.301/3104.360/13.838 ms, pipe 10, ipg/ewma 0.340/0.243 ms > > After this patch, attaching xdp program no longer cause flood ping to loss > any packets, as shown in ping statistics below: > --- 169.254.1.2 ping statistics --- > 100000 packets transmitted, 100000 received, 0% packet loss, time 32326ms > rtt min/avg/max/mdev = 0.027/0.231/19.589/0.155 ms, pipe 2, ipg/ewma 0.323/0.322 ms > > On the other hand, this patch is also tested with tools/testing/selftests/ > bpf/xdp_hw_metadata app to make sure XDP zero-copy is working fine with > XDP Tx and Rx metadata. Below is the result of last packet after received > 10000 UDP packets with interval 1 ms: > poll: 1 (0) skip=0 fail=0 redir=10000 > xsk_ring_cons__peek: 1 > 0x55881c7ef7a8: rx_desc[9999]->addr=8f110 addr=8f110 comp_addr=8f110 EoP > rx_hash: 0xFB9BB6A3 with RSS type:0x1 > HW RX-time: 1733923136269470866 (sec:1733923136.2695) delta to User RX-time sec:0.0000 (43.280 usec) > XDP RX-time: 1733923136269482482 (sec:1733923136.2695) delta to User RX-time sec:0.0000 (31.664 usec) > No rx_vlan_tci or rx_vlan_proto, err=-95 > 0x55881c7ef7a8: ping-pong with csum=ab19 (want 315b) csum_start=34 csum_offset=6 > 0x55881c7ef7a8: complete tx idx=9999 addr=f010 > HW TX-complete-time: 1733923136269591637 (sec:1733923136.2696) delta to User TX-complete-time sec:0.0001 (108.571 usec) > XDP RX-time: 1733923136269482482 (sec:1733923136.2695) delta to User TX-complete-time sec:0.0002 (217.726 usec) > HW RX-time: 1733923136269470866 (sec:1733923136.2695) delta to HW TX-complete-time sec:0.0001 (120.771 usec) > 0x55881c7ef7a8: complete rx idx=10127 addr=8f110 > > Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx> > --- > V2 changelog: > - show some examples of problem in commit msg. (Vinicius) > - igc_close()/igc_open() are too big a hammer for installing a new XDP > program. Only do we we really need. (Vinicius) > --- > drivers/net/ethernet/intel/igc/igc_xdp.c | 19 +++++++++++++++---- > 1 file changed, 15 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/intel/igc/igc_xdp.c b/drivers/net/ethernet/intel/igc/igc_xdp.c > index 869815f48ac1..64b04aad614c 100644 > --- a/drivers/net/ethernet/intel/igc/igc_xdp.c > +++ b/drivers/net/ethernet/intel/igc/igc_xdp.c > @@ -14,6 +14,7 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog, > bool if_running = netif_running(dev); > struct bpf_prog *old_prog; > bool need_update; > + int i; > > if (dev->mtu > ETH_DATA_LEN) { > /* For now, the driver doesn't support XDP functionality with > @@ -24,8 +25,13 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog, > } > > need_update = !!adapter->xdp_prog != !!prog; > - if (if_running && need_update) > - igc_close(dev); > + if (if_running && need_update) { > + for (i = 0; i < adapter->num_rx_queues; i++) { > + igc_disable_rx_ring(adapter->rx_ring[i]); > + igc_disable_tx_ring(adapter->tx_ring[i]); > + napi_disable(&adapter->rx_ring[i]->q_vector->napi); > + } > + } > > old_prog = xchg(&adapter->xdp_prog, prog); > if (old_prog) > @@ -36,8 +42,13 @@ int igc_xdp_set_prog(struct igc_adapter *adapter, struct bpf_prog *prog, > else > xdp_features_clear_redirect_target(dev); > > - if (if_running && need_update) > - igc_open(dev); > + if (if_running && need_update) { > + for (i = 0; i < adapter->num_rx_queues; i++) { > + napi_enable(&adapter->rx_ring[i]->q_vector->napi); > + igc_enable_tx_ring(adapter->tx_ring[i]); > + igc_enable_rx_ring(adapter->rx_ring[i]); I agree we could do better than igc_close/igc_open pair, but have you tried igc_down/igc_open instead? > + } > + } > > return 0; > } > -- > 2.34.1 >