myri10ge: add adaptive coalescing

@@ -75,7 +75,7 @@
 #include "myri10ge_mcp.h"
 #include "myri10ge_mcp_gen_header.h"
 
-#define MYRI10GE_VERSION_STR "1.5.0-1.432"
+#define MYRI10GE_VERSION_STR "1.5.1-1.446"
 
 MODULE_DESCRIPTION("Myricom 10G driver (10GbE)");
 MODULE_AUTHOR("Maintainer: [email protected]");

@@ -83,6 +83,7 @@
 MODULE_LICENSE("Dual BSD/GPL");
 
 #define MYRI10GE_MAX_ETHER_MTU 9014
+#define MYRI10GE_INTR_COAL_PERIOD 4
 
 #define MYRI10GE_ETH_STOPPED 0
 #define MYRI10GE_ETH_STOPPING 1

@@ -197,6 +198,15 @@
 	char irq_desc[32];
 };
 
+struct myri10ge_adapt_intr_coal {
+	int enabled;
+	int usecs;
+	int big_usecs;
+	unsigned long old_tx_bytes;
+	unsigned long old_rx_bytes;
+	struct timer_list timer;
+};
+
 struct myri10ge_priv {
 	struct myri10ge_slice_state *ss;
 	int tx_boundary;	/* boundary transmits cannot cross */

@@ -228,6 +238,7 @@
 	unsigned int rdma_tags_available;
 	int intr_coal_delay;
 	__be32 __iomem *intr_coal_delay_ptr;
+	struct myri10ge_adapt_intr_coal adapt_coal;
 	int mtrr;
 	int wc_enabled;
 	int down_cnt;

@@ -292,6 +303,16 @@
 module_param(myri10ge_intr_coal_delay, int, S_IRUGO);
 MODULE_PARM_DESC(myri10ge_intr_coal_delay, "Interrupt coalescing delay");
 
+static int myri10ge_adapt_med_thresh = 8 * 1024 * 1024;
+module_param(myri10ge_adapt_med_thresh, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(myri10ge_adapt_med_thresh,
+		 "Low latency limit, in bytes per second");
+
+static int myri10ge_adapt_big_thresh = 256 * 1024 * 1024;
+module_param(myri10ge_adapt_big_thresh, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(myri10ge_adapt_big_thresh,
+		 "Bulk latency limit, in bytes per second");
+
 static int myri10ge_flow_control = 1;
 module_param(myri10ge_flow_control, int, S_IRUGO);
 MODULE_PARM_DESC(myri10ge_flow_control, "Pause parameter");

@@ -1054,6 +1075,9 @@
 		ss->tx.stop_queue = 0;
 	}
 
+	mgp->adapt_coal.usecs = -1;
+	mgp->adapt_coal.old_rx_bytes = 0;
+	mgp->adapt_coal.old_tx_bytes = 0;
 	status = myri10ge_update_mac_address(mgp, mgp->dev->dev_addr);
 	myri10ge_change_pause(mgp, mgp->pause);
 	myri10ge_set_multicast_list(mgp->dev);

@@ -1648,6 +1672,7 @@
 	struct myri10ge_priv *mgp = netdev_priv(netdev);
 
 	coal->rx_coalesce_usecs = mgp->intr_coal_delay;
+	coal->use_adaptive_rx_coalesce = mgp->adapt_coal.enabled;
 	return 0;
 }
 

@@ -1655,6 +1680,20 @@
 myri10ge_set_coalesce(struct net_device *netdev, struct ethtool_coalesce *coal)
 {
 	struct myri10ge_priv *mgp = netdev_priv(netdev);
+	struct myri10ge_adapt_intr_coal *adapt = &mgp->adapt_coal;
+
+	if (coal->use_adaptive_rx_coalesce != adapt->enabled) {
+		adapt->enabled = coal->use_adaptive_rx_coalesce;
+		if (adapt->enabled) {
+			adapt->big_usecs = mgp->intr_coal_delay;
+			adapt->timer.expires =
+			    jiffies + HZ / MYRI10GE_INTR_COAL_PERIOD;
+			if (mgp->running)
+				add_timer(&adapt->timer);
+		} else {
+			del_timer_sync(&adapt->timer);
+		}
+	}
 
 	mgp->intr_coal_delay = coal->rx_coalesce_usecs;
 	put_be32(htonl(mgp->intr_coal_delay), mgp->intr_coal_delay_ptr);

@@ -2515,6 +2554,11 @@
 	mgp->running = MYRI10GE_ETH_RUNNING;
 	mgp->watchdog_timer.expires = jiffies + myri10ge_watchdog_timeout * HZ;
 	add_timer(&mgp->watchdog_timer);
+	if (mgp->adapt_coal.enabled) {
+		mgp->adapt_coal.timer.expires =
+		    jiffies + HZ / MYRI10GE_INTR_COAL_PERIOD;
+		add_timer(&mgp->adapt_coal.timer);
+	}
 	netif_tx_wake_all_queues(dev);
 
 	return 0;

@@ -2548,6 +2592,7 @@
 		return 0;
 
 	del_timer_sync(&mgp->watchdog_timer);
+	del_timer_sync(&mgp->adapt_coal.timer);
 	mgp->running = MYRI10GE_ETH_STOPPING;
 	for (i = 0; i < mgp->num_slices; i++) {
 		napi_disable(&mgp->ss[i].napi);

@@ -3009,6 +3054,46 @@
 	return stats;
 }
 
+static void myri10ge_intr_coal_timer(unsigned long arg)
+{
+	struct myri10ge_priv *mgp = (struct myri10ge_priv *)arg;
+	struct net_device_stats *stats = &mgp->stats;
+	struct myri10ge_adapt_intr_coal *adapt = &mgp->adapt_coal;
+	unsigned long bytes_per_sec, bytes, usecs;
+	unsigned long tx_bytes, rx_bytes;
+
+	if (adapt->enabled == 0)
+		return;
+
+	/* snapshot stats */
+	(void)myri10ge_get_stats(mgp->dev);
+
+	tx_bytes = stats->tx_bytes;
+	rx_bytes = stats->rx_bytes;
+
+	/* calculate bytes since last snapshot */
+	bytes = tx_bytes - adapt->old_tx_bytes;
+	bytes += rx_bytes - adapt->old_rx_bytes;
+
+	/* store snapshot for next time */
+	adapt->old_tx_bytes = tx_bytes;
+	adapt->old_rx_bytes = rx_bytes;
+
+	bytes_per_sec = bytes * MYRI10GE_INTR_COAL_PERIOD;
+	if (bytes_per_sec < myri10ge_adapt_med_thresh)
+		usecs = 0;
+	else if (bytes_per_sec < myri10ge_adapt_big_thresh)
+		usecs = adapt->big_usecs / 5;
+	else
+		usecs = adapt->big_usecs;
+
+	if (adapt->usecs != usecs) {
+		adapt->usecs = usecs;
+		put_be32(htonl(usecs), mgp->intr_coal_delay_ptr);
+	}
+	mod_timer(&adapt->timer, jiffies + HZ / MYRI10GE_INTR_COAL_PERIOD);
+}
+
 static void myri10ge_set_multicast_list(struct net_device *dev)
 {
 	struct myri10ge_priv *mgp = netdev_priv(dev);

@@ -3969,6 +4054,8 @@
 	/* Setup the watchdog timer */
 	setup_timer(&mgp->watchdog_timer, myri10ge_watchdog_timer,
 		    (unsigned long)mgp);
+	setup_timer(&mgp->adapt_coal.timer, myri10ge_intr_coal_timer,
+		    (unsigned long)mgp);
 
 	spin_lock_init(&mgp->stats_lock);
 	SET_ETHTOOL_OPS(netdev, &myri10ge_ethtool_ops);