From 60d51134281fbeb352013d782a440fb338d31f01 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 8 Dec 2009 07:22:03 +0000 Subject: [PATCH] ixgbe: Fix TX stats accounting Here is an updated version, because ixgbe_get_ethtool_stats() needs to call dev_get_stats() or "ethtool -S" wont give correct tx_bytes/tx_packets values. Several cpus can update netdev->stats.tx_bytes & netdev->stats.tx_packets in parallel. In this case, TX stats are under estimated and false sharing takes place. After a pktgen session sending exactly 200000000 packets : # ifconfig fiber0 | grep TX TX packets:198501982 errors:0 dropped:0 overruns:0 carrier:0 Multi queue devices should instead use txq->tx_bytes & txq->tx_packets in their xmit() method (appropriate txq lock already held by caller, no cache line miss), or use appropriate locking. After patch, same pktgen session gives : # ifconfig fiber0 | grep TX TX packets:200000000 errors:0 dropped:0 overruns:0 carrier:0 Signed-off-by: Eric Dumazet Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- drivers/net/ixgbe/ixgbe_ethtool.c | 1 + drivers/net/ixgbe/ixgbe_main.c | 20 ++++---------------- 2 files changed, 5 insertions(+), 16 deletions(-) diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c index 06a9d18bbdbc..0bd49d3b9f65 100644 --- a/drivers/net/ixgbe/ixgbe_ethtool.c +++ b/drivers/net/ixgbe/ixgbe_ethtool.c @@ -990,6 +990,7 @@ static void ixgbe_get_ethtool_stats(struct net_device *netdev, char *p = NULL; ixgbe_update_stats(adapter); + dev_get_stats(netdev); for (i = 0; i < IXGBE_GLOBAL_STATS_LEN; i++) { switch (ixgbe_gstrings_stats[i].type) { case NETDEV_STATS: diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index 247ed2a24769..4374f441c426 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -435,8 +435,6 @@ static bool ixgbe_clean_tx_irq(struct ixgbe_q_vector *q_vector, tx_ring->total_packets += total_packets; tx_ring->stats.packets += total_packets; tx_ring->stats.bytes += total_bytes; - netdev->stats.tx_bytes += total_bytes; - netdev->stats.tx_packets += total_packets; return (count < tx_ring->work_limit); } @@ -5327,6 +5325,7 @@ static netdev_tx_t ixgbe_xmit_frame(struct sk_buff *skb, { struct ixgbe_adapter *adapter = netdev_priv(netdev); struct ixgbe_ring *tx_ring; + struct netdev_queue *txq; unsigned int first; unsigned int tx_flags = 0; u8 hdr_len = 0; @@ -5424,6 +5423,9 @@ static netdev_tx_t ixgbe_xmit_frame(struct sk_buff *skb, tx_ring->atr_count = 0; } } + txq = netdev_get_tx_queue(netdev, tx_ring->queue_index); + txq->tx_bytes += skb->len; + txq->tx_packets++; ixgbe_tx_queue(adapter, tx_ring, tx_flags, count, skb->len, hdr_len); ixgbe_maybe_stop_tx(netdev, tx_ring, DESC_NEEDED); @@ -5437,19 +5439,6 @@ static netdev_tx_t ixgbe_xmit_frame(struct sk_buff *skb, return NETDEV_TX_OK; } -/** - * ixgbe_get_stats - Get System Network Statistics - * @netdev: network interface device structure - * - * Returns the address of the device statistics structure. - * The statistics are actually updated from the timer callback. - **/ -static struct net_device_stats *ixgbe_get_stats(struct net_device *netdev) -{ - /* only return the current stats */ - return &netdev->stats; -} - /** * ixgbe_set_mac - Change the Ethernet Address of the NIC * @netdev: network interface device structure @@ -5580,7 +5569,6 @@ static const struct net_device_ops ixgbe_netdev_ops = { .ndo_stop = ixgbe_close, .ndo_start_xmit = ixgbe_xmit_frame, .ndo_select_queue = ixgbe_select_queue, - .ndo_get_stats = ixgbe_get_stats, .ndo_set_rx_mode = ixgbe_set_rx_mode, .ndo_set_multicast_list = ixgbe_set_rx_mode, .ndo_validate_addr = eth_validate_addr, -- 2.20.1