diff mbox series

[iwl-next,v2,1/1] igc: Improve XDP_SETUP_PROG process

Message ID 20241211134532.3489335-1-yoong.siang.song@intel.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series [iwl-next,v2,1/1] igc: Improve XDP_SETUP_PROG process | expand

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Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Song Yoong Siang Dec. 11, 2024, 1:45 p.m. UTC
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@intel.com>
---
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 mbox series

Patch

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]);
+		}
+	}
 
 	return 0;
 }