From 15070919f801348e9a9a2ea96f427d8b621f3cd5 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Mon, 2 Mar 2020 14:46:28 +0100 Subject: [PATCH] mvneta: add XDP ethtool errors stats for TX to driver Adding ethtool stats for when XDP transmitted packets overrun the TX queue. This is recorded separately for XDP_TX and ndo_xdp_xmit. This is an important aid for troubleshooting XDP based setups. It is currently a known weakness and property of XDP that there isn't any push-back or congestion feedback when transmitting frames via XDP. It's easy to realise when redirecting from a higher speed link into a slower speed link, or simply two ingress links into a single egress. The situation can also happen when Ethernet flow control is active. For testing the patch and provoking the situation to occur on my Espressobin board, I configured the TX-queue to be smaller (434) than RX-queue (512) and overload network with large MTU size frames (as a larger frame takes longer to transmit). Hopefully the upcoming XDP TX hook can be extended to provide insight into these TX queue overflows, to allow programmable adaptation strategies. Signed-off-by: Jesper Dangaard Brouer Acked-by: Lorenzo Bianconi Signed-off-by: David S. Miller --- drivers/net/ethernet/marvell/mvneta.c | 30 +++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index b22eeb5f8700..bc488e8b8e45 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -344,8 +344,10 @@ enum { ETHTOOL_XDP_REDIRECT, ETHTOOL_XDP_PASS, ETHTOOL_XDP_DROP, - ETHTOOL_XDP_XMIT, ETHTOOL_XDP_TX, + ETHTOOL_XDP_TX_ERR, + ETHTOOL_XDP_XMIT, + ETHTOOL_XDP_XMIT_ERR, ETHTOOL_MAX_STATS, }; @@ -404,7 +406,9 @@ static const struct mvneta_statistic mvneta_statistics[] = { { ETHTOOL_XDP_PASS, T_SW, "rx_xdp_pass", }, { ETHTOOL_XDP_DROP, T_SW, "rx_xdp_drop", }, { ETHTOOL_XDP_TX, T_SW, "rx_xdp_tx", }, + { ETHTOOL_XDP_TX_ERR, T_SW, "rx_xdp_tx_errors", }, { ETHTOOL_XDP_XMIT, T_SW, "tx_xdp_xmit", }, + { ETHTOOL_XDP_XMIT_ERR, T_SW, "tx_xdp_xmit_errors", }, }; struct mvneta_stats { @@ -417,7 +421,9 @@ struct mvneta_stats { u64 xdp_pass; u64 xdp_drop; u64 xdp_xmit; + u64 xdp_xmit_err; u64 xdp_tx; + u64 xdp_tx_err; }; struct mvneta_ethtool_stats { @@ -2059,6 +2065,7 @@ mvneta_xdp_submit_frame(struct mvneta_port *pp, struct mvneta_tx_queue *txq, static int mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp) { + struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats); struct mvneta_tx_queue *txq; struct netdev_queue *nq; struct xdp_frame *xdpf; @@ -2076,8 +2083,6 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp) __netif_tx_lock(nq, cpu); ret = mvneta_xdp_submit_frame(pp, txq, xdpf, false); if (ret == MVNETA_XDP_TX) { - struct mvneta_pcpu_stats *stats = this_cpu_ptr(pp->stats); - u64_stats_update_begin(&stats->syncp); stats->es.ps.tx_bytes += xdpf->len; stats->es.ps.tx_packets++; @@ -2085,6 +2090,10 @@ mvneta_xdp_xmit_back(struct mvneta_port *pp, struct xdp_buff *xdp) u64_stats_update_end(&stats->syncp); mvneta_txq_pend_desc_add(pp, txq, 0); + } else { + u64_stats_update_begin(&stats->syncp); + stats->es.ps.xdp_tx_err++; + u64_stats_update_end(&stats->syncp); } __netif_tx_unlock(nq); @@ -2128,6 +2137,7 @@ mvneta_xdp_xmit(struct net_device *dev, int num_frame, stats->es.ps.tx_bytes += nxmit_byte; stats->es.ps.tx_packets += nxmit; stats->es.ps.xdp_xmit += nxmit; + stats->es.ps.xdp_xmit_err += num_frame - nxmit; u64_stats_update_end(&stats->syncp); return nxmit; @@ -2152,7 +2162,7 @@ mvneta_run_xdp(struct mvneta_port *pp, struct mvneta_rx_queue *rxq, int err; err = xdp_do_redirect(pp->dev, xdp, prog); - if (err) { + if (unlikely(err)) { ret = MVNETA_XDP_DROPPED; page_pool_put_page(rxq->page_pool, virt_to_head_page(xdp->data), len, @@ -4518,6 +4528,8 @@ mvneta_ethtool_update_pcpu_stats(struct mvneta_port *pp, u64 skb_alloc_error; u64 refill_error; u64 xdp_redirect; + u64 xdp_xmit_err; + u64 xdp_tx_err; u64 xdp_pass; u64 xdp_drop; u64 xdp_xmit; @@ -4532,7 +4544,9 @@ mvneta_ethtool_update_pcpu_stats(struct mvneta_port *pp, xdp_pass = stats->es.ps.xdp_pass; xdp_drop = stats->es.ps.xdp_drop; xdp_xmit = stats->es.ps.xdp_xmit; + xdp_xmit_err = stats->es.ps.xdp_xmit_err; xdp_tx = stats->es.ps.xdp_tx; + xdp_tx_err = stats->es.ps.xdp_tx_err; } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); es->skb_alloc_error += skb_alloc_error; @@ -4541,7 +4555,9 @@ mvneta_ethtool_update_pcpu_stats(struct mvneta_port *pp, es->ps.xdp_pass += xdp_pass; es->ps.xdp_drop += xdp_drop; es->ps.xdp_xmit += xdp_xmit; + es->ps.xdp_xmit_err += xdp_xmit_err; es->ps.xdp_tx += xdp_tx; + es->ps.xdp_tx_err += xdp_tx_err; } } @@ -4594,9 +4610,15 @@ static void mvneta_ethtool_update_stats(struct mvneta_port *pp) case ETHTOOL_XDP_TX: pp->ethtool_stats[i] = stats.ps.xdp_tx; break; + case ETHTOOL_XDP_TX_ERR: + pp->ethtool_stats[i] = stats.ps.xdp_tx_err; + break; case ETHTOOL_XDP_XMIT: pp->ethtool_stats[i] = stats.ps.xdp_xmit; break; + case ETHTOOL_XDP_XMIT_ERR: + pp->ethtool_stats[i] = stats.ps.xdp_xmit_err; + break; } break; } -- GitLab