From 6eb5a7f1dbd56883680290f6a0bd2d8d15f8ff58 Mon Sep 17 00:00:00 2001 From: Alexander Duyck Date: Tue, 8 Jul 2008 15:14:44 -0700 Subject: [PATCH] igb: Improve multiqueue AIM support Improve multiqueue performance Change itr_val to reflect ITR timer value instead of ints/sec Cleaned up AIM algorithms in general Based on work by Mitch Williams Signed-off-by: Alexander Duyck Acked-by: Mitch Williams Signed-off-by: Jeff Kirsher Signed-off-by: Jeff Garzik --- drivers/net/igb/igb.h | 8 +- drivers/net/igb/igb_ethtool.c | 17 ++-- drivers/net/igb/igb_main.c | 169 +++++++++++++++++++--------------- 3 files changed, 113 insertions(+), 81 deletions(-) diff --git a/drivers/net/igb/igb.h b/drivers/net/igb/igb.h index c25ca17d32..56de7ec15b 100644 --- a/drivers/net/igb/igb.h +++ b/drivers/net/igb/igb.h @@ -47,7 +47,9 @@ struct igb_adapter; #define IGB_MIN_DYN_ITR 3000 #define IGB_MAX_DYN_ITR 96000 -#define IGB_START_ITR 6000 + +/* ((1000000000ns / (6000ints/s * 1024ns)) << 2 = 648 */ +#define IGB_START_ITR 648 #define IGB_DYN_ITR_PACKET_THRESHOLD 2 #define IGB_DYN_ITR_LENGTH_LOW 200 @@ -170,9 +172,10 @@ struct igb_ring { }; /* RX */ struct { - int no_itr_adjust; struct igb_queue_stats rx_stats; struct napi_struct napi; + int set_itr; + struct igb_ring *buddy; #ifdef CONFIG_IGB_LRO struct net_lro_mgr lro_mgr; bool lro_used; @@ -219,7 +222,6 @@ struct igb_adapter { u32 itr_setting; u16 tx_itr; u16 rx_itr; - int set_itr; struct work_struct reset_task; struct work_struct watchdog_task; diff --git a/drivers/net/igb/igb_ethtool.c b/drivers/net/igb/igb_ethtool.c index 7db1830937..11aee13099 100644 --- a/drivers/net/igb/igb_ethtool.c +++ b/drivers/net/igb/igb_ethtool.c @@ -1861,6 +1861,8 @@ static int igb_set_coalesce(struct net_device *netdev, struct ethtool_coalesce *ec) { struct igb_adapter *adapter = netdev_priv(netdev); + struct e1000_hw *hw = &adapter->hw; + int i; if ((ec->rx_coalesce_usecs > IGB_MAX_ITR_USECS) || ((ec->rx_coalesce_usecs > 3) && @@ -1869,13 +1871,16 @@ static int igb_set_coalesce(struct net_device *netdev, return -EINVAL; /* convert to rate of irq's per second */ - if (ec->rx_coalesce_usecs <= 3) + if (ec->rx_coalesce_usecs && ec->rx_coalesce_usecs <= 3) { adapter->itr_setting = ec->rx_coalesce_usecs; - else - adapter->itr_setting = (1000000 / ec->rx_coalesce_usecs); + adapter->itr = IGB_START_ITR; + } else { + adapter->itr_setting = ec->rx_coalesce_usecs << 2; + adapter->itr = adapter->itr_setting; + } - if (netif_running(netdev)) - igb_reinit_locked(adapter); + for (i = 0; i < adapter->num_rx_queues; i++) + wr32(adapter->rx_ring[i].itr_register, adapter->itr); return 0; } @@ -1888,7 +1893,7 @@ static int igb_get_coalesce(struct net_device *netdev, if (adapter->itr_setting <= 3) ec->rx_coalesce_usecs = adapter->itr_setting; else - ec->rx_coalesce_usecs = 1000000 / adapter->itr_setting; + ec->rx_coalesce_usecs = adapter->itr_setting >> 2; return 0; } diff --git a/drivers/net/igb/igb_main.c b/drivers/net/igb/igb_main.c index 2a5303c311..aaed129f4c 100644 --- a/drivers/net/igb/igb_main.c +++ b/drivers/net/igb/igb_main.c @@ -255,6 +255,8 @@ static int igb_alloc_queues(struct igb_adapter *adapter) return -ENOMEM; } + adapter->rx_ring->buddy = adapter->tx_ring; + for (i = 0; i < adapter->num_tx_queues; i++) { struct igb_ring *ring = &(adapter->tx_ring[i]); ring->adapter = adapter; @@ -375,7 +377,7 @@ static void igb_configure_msix(struct igb_adapter *adapter) igb_assign_vector(adapter, IGB_N0_QUEUE, i, vector++); adapter->eims_enable_mask |= tx_ring->eims_value; if (tx_ring->itr_val) - writel(1000000000 / (tx_ring->itr_val * 256), + writel(tx_ring->itr_val, hw->hw_addr + tx_ring->itr_register); else writel(1, hw->hw_addr + tx_ring->itr_register); @@ -383,10 +385,11 @@ static void igb_configure_msix(struct igb_adapter *adapter) for (i = 0; i < adapter->num_rx_queues; i++) { struct igb_ring *rx_ring = &adapter->rx_ring[i]; + rx_ring->buddy = 0; igb_assign_vector(adapter, i, IGB_N0_QUEUE, vector++); adapter->eims_enable_mask |= rx_ring->eims_value; if (rx_ring->itr_val) - writel(1000000000 / (rx_ring->itr_val * 256), + writel(rx_ring->itr_val, hw->hw_addr + rx_ring->itr_register); else writel(1, hw->hw_addr + rx_ring->itr_register); @@ -449,7 +452,7 @@ static int igb_request_msix(struct igb_adapter *adapter) if (err) goto out; ring->itr_register = E1000_EITR(0) + (vector << 2); - ring->itr_val = adapter->itr; + ring->itr_val = 976; /* ~4000 ints/sec */ vector++; } for (i = 0; i < adapter->num_rx_queues; i++) { @@ -1898,8 +1901,7 @@ static void igb_configure_rx(struct igb_adapter *adapter) mdelay(10); if (adapter->itr_setting > 3) - wr32(E1000_ITR, - 1000000000 / (adapter->itr * 256)); + wr32(E1000_ITR, adapter->itr); /* Setup the HW Rx Head and Tail Descriptor Pointers and * the Base and Length of the Rx Descriptor Ring */ @@ -2463,38 +2465,60 @@ enum latency_range { }; -static void igb_lower_rx_eitr(struct igb_adapter *adapter, - struct igb_ring *rx_ring) +/** + * igb_update_ring_itr - update the dynamic ITR value based on packet size + * + * Stores a new ITR value based on strictly on packet size. This + * algorithm is less sophisticated than that used in igb_update_itr, + * due to the difficulty of synchronizing statistics across multiple + * receive rings. The divisors and thresholds used by this fuction + * were determined based on theoretical maximum wire speed and testing + * data, in order to minimize response time while increasing bulk + * throughput. + * This functionality is controlled by the InterruptThrottleRate module + * parameter (see igb_param.c) + * NOTE: This function is called only when operating in a multiqueue + * receive environment. + * @rx_ring: pointer to ring + **/ +static void igb_update_ring_itr(struct igb_ring *rx_ring) { - struct e1000_hw *hw = &adapter->hw; - int new_val; + int new_val = rx_ring->itr_val; + int avg_wire_size = 0; + struct igb_adapter *adapter = rx_ring->adapter; - new_val = rx_ring->itr_val / 2; - if (new_val < IGB_MIN_DYN_ITR) - new_val = IGB_MIN_DYN_ITR; + if (!rx_ring->total_packets) + goto clear_counts; /* no packets, so don't do anything */ - if (new_val != rx_ring->itr_val) { - rx_ring->itr_val = new_val; - wr32(rx_ring->itr_register, - 1000000000 / (new_val * 256)); + /* For non-gigabit speeds, just fix the interrupt rate at 4000 + * ints/sec - ITR timer value of 120 ticks. + */ + if (adapter->link_speed != SPEED_1000) { + new_val = 120; + goto set_itr_val; } -} + avg_wire_size = rx_ring->total_bytes / rx_ring->total_packets; -static void igb_raise_rx_eitr(struct igb_adapter *adapter, - struct igb_ring *rx_ring) -{ - struct e1000_hw *hw = &adapter->hw; - int new_val; + /* Add 24 bytes to size to account for CRC, preamble, and gap */ + avg_wire_size += 24; + + /* Don't starve jumbo frames */ + avg_wire_size = min(avg_wire_size, 3000); - new_val = rx_ring->itr_val * 2; - if (new_val > IGB_MAX_DYN_ITR) - new_val = IGB_MAX_DYN_ITR; + /* Give a little boost to mid-size frames */ + if ((avg_wire_size > 300) && (avg_wire_size < 1200)) + new_val = avg_wire_size / 3; + else + new_val = avg_wire_size / 2; +set_itr_val: if (new_val != rx_ring->itr_val) { rx_ring->itr_val = new_val; - wr32(rx_ring->itr_register, - 1000000000 / (new_val * 256)); + rx_ring->set_itr = 1; } +clear_counts: + rx_ring->total_bytes = 0; + rx_ring->total_packets = 0; } /** @@ -2561,8 +2585,7 @@ update_itr_done: return retval; } -static void igb_set_itr(struct igb_adapter *adapter, u16 itr_register, - int rx_only) +static void igb_set_itr(struct igb_adapter *adapter) { u16 current_itr; u32 new_itr = adapter->itr; @@ -2578,26 +2601,23 @@ static void igb_set_itr(struct igb_adapter *adapter, u16 itr_register, adapter->rx_itr, adapter->rx_ring->total_packets, adapter->rx_ring->total_bytes); - /* conservative mode (itr 3) eliminates the lowest_latency setting */ - if (adapter->itr_setting == 3 && adapter->rx_itr == lowest_latency) - adapter->rx_itr = low_latency; - if (!rx_only) { + if (adapter->rx_ring->buddy) { adapter->tx_itr = igb_update_itr(adapter, adapter->tx_itr, adapter->tx_ring->total_packets, adapter->tx_ring->total_bytes); - /* conservative mode (itr 3) eliminates the - * lowest_latency setting */ - if (adapter->itr_setting == 3 && - adapter->tx_itr == lowest_latency) - adapter->tx_itr = low_latency; current_itr = max(adapter->rx_itr, adapter->tx_itr); } else { current_itr = adapter->rx_itr; } + /* conservative mode (itr 3) eliminates the lowest_latency setting */ + if (adapter->itr_setting == 3 && + current_itr == lowest_latency) + current_itr = low_latency; + switch (current_itr) { /* counts and packets in update_itr are dependent on these numbers */ case lowest_latency: @@ -2614,6 +2634,13 @@ static void igb_set_itr(struct igb_adapter *adapter, u16 itr_register, } set_itr_now: + adapter->rx_ring->total_bytes = 0; + adapter->rx_ring->total_packets = 0; + if (adapter->rx_ring->buddy) { + adapter->rx_ring->buddy->total_bytes = 0; + adapter->rx_ring->buddy->total_packets = 0; + } + if (new_itr != adapter->itr) { /* this attempts to bias the interrupt rate towards Bulk * by adding intermediate steps when interrupt rate is @@ -2628,7 +2655,8 @@ set_itr_now: * ends up being correct. */ adapter->itr = new_itr; - adapter->set_itr = 1; + adapter->rx_ring->itr_val = 1000000000 / (new_itr * 256); + adapter->rx_ring->set_itr = 1; } return; @@ -2979,6 +3007,7 @@ static int igb_xmit_frame_ring_adv(struct sk_buff *skb, /* this is a hard error */ return NETDEV_TX_BUSY; } + skb_orphan(skb); if (adapter->vlgrp && vlan_tx_tag_present(skb)) { tx_flags |= IGB_TX_FLAGS_VLAN; @@ -3312,8 +3341,6 @@ static irqreturn_t igb_msix_tx(int irq, void *data) struct igb_adapter *adapter = tx_ring->adapter; struct e1000_hw *hw = &adapter->hw; - if (!tx_ring->itr_val) - wr32(E1000_EIMC, tx_ring->eims_value); #ifdef CONFIG_DCA if (adapter->flags & IGB_FLAG_DCA_ENABLED) igb_update_tx_dca(tx_ring); @@ -3332,21 +3359,36 @@ static irqreturn_t igb_msix_tx(int irq, void *data) return IRQ_HANDLED; } +static void igb_write_itr(struct igb_ring *ring) +{ + struct e1000_hw *hw = &ring->adapter->hw; + if ((ring->adapter->itr_setting & 3) && ring->set_itr) { + switch (hw->mac.type) { + case e1000_82576: + wr32(ring->itr_register, + ring->itr_val | + 0x80000000); + break; + default: + wr32(ring->itr_register, + ring->itr_val | + (ring->itr_val << 16)); + break; + } + ring->set_itr = 0; + } +} + static irqreturn_t igb_msix_rx(int irq, void *data) { struct igb_ring *rx_ring = data; struct igb_adapter *adapter = rx_ring->adapter; - struct e1000_hw *hw = &adapter->hw; /* Write the ITR value calculated at the end of the * previous interrupt. */ - if (adapter->set_itr) { - wr32(rx_ring->itr_register, - 1000000000 / (rx_ring->itr_val * 256)); - adapter->set_itr = 0; - } + igb_write_itr(rx_ring); if (netif_rx_schedule_prep(adapter->netdev, &rx_ring->napi)) __netif_rx_schedule(adapter->netdev, &rx_ring->napi); @@ -3493,13 +3535,7 @@ static irqreturn_t igb_intr_msi(int irq, void *data) /* read ICR disables interrupts using IAM */ u32 icr = rd32(E1000_ICR); - /* Write the ITR value calculated at the end of the - * previous interrupt. - */ - if (adapter->set_itr) { - wr32(E1000_ITR, 1000000000 / (adapter->itr * 256)); - adapter->set_itr = 0; - } + igb_write_itr(adapter->rx_ring); if (icr & (E1000_ICR_RXSEQ | E1000_ICR_LSC)) { hw->mac.get_link_status = 1; @@ -3529,13 +3565,7 @@ static irqreturn_t igb_intr(int irq, void *data) if (!icr) return IRQ_NONE; /* Not our interrupt */ - /* Write the ITR value calculated at the end of the - * previous interrupt. - */ - if (adapter->set_itr) { - wr32(E1000_ITR, 1000000000 / (adapter->itr * 256)); - adapter->set_itr = 0; - } + igb_write_itr(adapter->rx_ring); /* IMS will not auto-mask if INT_ASSERTED is not set, and if it is * not set, then the adapter didn't send an interrupt */ @@ -3585,7 +3615,7 @@ static int igb_poll(struct napi_struct *napi, int budget) if ((tx_clean_complete && (work_done < budget)) || !netif_running(netdev)) { if (adapter->itr_setting & 3) - igb_set_itr(adapter, E1000_ITR, false); + igb_set_itr(adapter); netif_rx_complete(netdev, napi); if (!test_bit(__IGB_DOWN, &adapter->state)) igb_irq_enable(adapter); @@ -3619,15 +3649,11 @@ static int igb_clean_rx_ring_msix(struct napi_struct *napi, int budget) quit_polling: netif_rx_complete(netdev, napi); - wr32(E1000_EIMS, rx_ring->eims_value); - if ((adapter->itr_setting & 3) && !rx_ring->no_itr_adjust && - (rx_ring->total_packets > IGB_DYN_ITR_PACKET_THRESHOLD)) { - int mean_size = rx_ring->total_bytes / - rx_ring->total_packets; - if (mean_size < IGB_DYN_ITR_LENGTH_LOW) - igb_raise_rx_eitr(adapter, rx_ring); - else if (mean_size > IGB_DYN_ITR_LENGTH_HIGH) - igb_lower_rx_eitr(adapter, rx_ring); + if (adapter->itr_setting & 3) { + if (adapter->num_rx_queues == 1) + igb_set_itr(adapter); + else + igb_update_ring_itr(rx_ring); } if (!test_bit(__IGB_DOWN, &adapter->state)) @@ -3972,7 +3998,6 @@ send_up: dev_kfree_skb_irq(skb); goto next_desc; } - rx_ring->no_itr_adjust |= (staterr & E1000_RXD_STAT_DYNINT); total_bytes += skb->len; total_packets++; -- 2.39.5