From c2837423cb54551302f037106830ee607b4563e0 Mon Sep 17 00:00:00 2001 From: Jose Abreu Date: Thu, 14 Nov 2019 12:42:50 +0100 Subject: net: stmmac: Rework TX Coalesce logic Coalesce logic currently increments the number of packets and sets the IC bit when the coalesced packets have passed a given limit. This does not reflect very well what coalesce was meant for as we can have a large number of packets that are coalesced and then a single one, sent later on that has the IC bit. Rework the logic so that it coalesces only upon a limit of packets and sets the IC bit for large number of packets. Signed-off-by: Jose Abreu Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 61 ++++++++++++++++------- 1 file changed, 42 insertions(+), 19 deletions(-) (limited to 'drivers/net/ethernet/stmicro') diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 400fbb727fd5..4ba250a9008f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -2916,16 +2916,17 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) struct stmmac_priv *priv = netdev_priv(dev); int nfrags = skb_shinfo(skb)->nr_frags; u32 queue = skb_get_queue_mapping(skb); + unsigned int first_entry, tx_packets; + int tmp_pay_len = 0, first_tx; struct stmmac_tx_queue *tx_q; - unsigned int first_entry; u8 proto_hdr_len, hdr; - int tmp_pay_len = 0; + bool has_vlan, set_ic; u32 pay_len, mss; dma_addr_t des; - bool has_vlan; int i; tx_q = &priv->tx_queue[queue]; + first_tx = tx_q->cur_tx; /* Compute header lengths */ if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) { @@ -3033,16 +3034,27 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) tx_q->tx_skbuff[tx_q->cur_tx] = skb; /* Manage tx mitigation */ - tx_q->tx_count_frames += nfrags + 1; - if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) && - !((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) && - priv->hwts_tx_en)) { - stmmac_tx_timer_arm(priv, queue); - } else { + tx_packets = (tx_q->cur_tx + 1) - first_tx; + tx_q->tx_count_frames += tx_packets; + + if ((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) && priv->hwts_tx_en) + set_ic = true; + else if (!priv->tx_coal_frames) + set_ic = false; + else if (tx_packets > priv->tx_coal_frames) + set_ic = true; + else if ((tx_q->tx_count_frames % priv->tx_coal_frames) < tx_packets) + set_ic = true; + else + set_ic = false; + + if (set_ic) { desc = &tx_q->dma_tx[tx_q->cur_tx]; tx_q->tx_count_frames = 0; stmmac_set_tx_ic(priv, desc); priv->xstats.tx_set_ic_bit++; + } else { + stmmac_tx_timer_arm(priv, queue); } /* We've used all descriptors we need for this skb, however, @@ -3133,6 +3145,7 @@ dma_map_err: */ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) { + unsigned int first_entry, tx_packets, enh_desc; struct stmmac_priv *priv = netdev_priv(dev); unsigned int nopaged_len = skb_headlen(skb); int i, csum_insertion = 0, is_jumbo = 0; @@ -3141,13 +3154,12 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) int gso = skb_shinfo(skb)->gso_type; struct dma_desc *desc, *first; struct stmmac_tx_queue *tx_q; - unsigned int first_entry; - unsigned int enh_desc; + bool has_vlan, set_ic; + int entry, first_tx; dma_addr_t des; - bool has_vlan; - int entry; tx_q = &priv->tx_queue[queue]; + first_tx = tx_q->cur_tx; if (priv->tx_path_in_lpi_mode) stmmac_disable_eee_mode(priv); @@ -3241,12 +3253,21 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) * This approach takes care about the fragments: desc is the first * element in case of no SG. */ - tx_q->tx_count_frames += nfrags + 1; - if (likely(priv->tx_coal_frames > tx_q->tx_count_frames) && - !((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) && - priv->hwts_tx_en)) { - stmmac_tx_timer_arm(priv, queue); - } else { + tx_packets = (entry + 1) - first_tx; + tx_q->tx_count_frames += tx_packets; + + if ((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) && priv->hwts_tx_en) + set_ic = true; + else if (!priv->tx_coal_frames) + set_ic = false; + else if (tx_packets > priv->tx_coal_frames) + set_ic = true; + else if ((tx_q->tx_count_frames % priv->tx_coal_frames) < tx_packets) + set_ic = true; + else + set_ic = false; + + if (set_ic) { if (likely(priv->extend_desc)) desc = &tx_q->dma_etx[entry].basic; else @@ -3255,6 +3276,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) tx_q->tx_count_frames = 0; stmmac_set_tx_ic(priv, desc); priv->xstats.tx_set_ic_bit++; + } else { + stmmac_tx_timer_arm(priv, queue); } /* We've used all descriptors we need for this skb, however, -- cgit v1.2.3-59-g8ed1b