[net-next PATCH v2 1/2] net: pktgen: support injecting packets for qdisc testing

@@ -213,6 +213,7 @@
 /* Xmit modes */
 #define M_START_XMIT		0	/* Default normal TX */
 #define M_NETIF_RECEIVE 	1	/* Inject packets into stack */
+#define M_QUEUE_XMIT		2	/* Inject packet into qdisc */
 
 /* If lock -- protects updating of if_list */
 #define   if_lock(t)           spin_lock(&(t->if_lock));

@@ -626,6 +627,8 @@ static int pktgen_if_show(struct seq_file *seq, void *v)
 
 	if (pkt_dev->xmit_mode == M_NETIF_RECEIVE)
 		seq_puts(seq, "     xmit_mode: netif_receive\n");
+	else if (pkt_dev->xmit_mode == M_QUEUE_XMIT)
+		seq_puts(seq, "     xmit_mode: xmit_queue\n");
 
 	seq_puts(seq, "     Flags: ");
 

@@ -1142,8 +1145,10 @@ static ssize_t pktgen_if_write(struct file *file,
 			return len;
 
 		i += len;
-		if ((value > 1) && (pkt_dev->xmit_mode == M_START_XMIT) &&
-		    (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))
+		if ((value > 1) &&
+		    ((pkt_dev->xmit_mode == M_QUEUE_XMIT) ||
+		     ((pkt_dev->xmit_mode == M_START_XMIT) &&
+		     (!(pkt_dev->odev->priv_flags & IFF_TX_SKB_SHARING)))))
 			return -ENOTSUPP;
 		pkt_dev->burst = value < 1 ? 1 : value;
 		sprintf(pg_result, "OK: burst=%d", pkt_dev->burst);

@@ -1198,6 +1203,9 @@ static ssize_t pktgen_if_write(struct file *file,
 			 * at module loading time
 			 */
 			pkt_dev->clone_skb = 0;
+		} else if (strcmp(f, "queue_xmit") == 0) {
+			pkt_dev->xmit_mode = M_QUEUE_XMIT;
+			pkt_dev->last_ok = 1;
 		} else {
 			sprintf(pg_result,
 				"xmit_mode -:%s:- unknown\nAvailable modes: %s",

@@ -3434,6 +3442,36 @@ static void pktgen_xmit(struct pktgen_dev *pkt_dev)
 #endif
 		} while (--burst > 0);
 		goto out; /* Skips xmit_mode M_START_XMIT */
+	} else if (pkt_dev->xmit_mode == M_QUEUE_XMIT) {
+		local_bh_disable();
+		atomic_inc(&pkt_dev->skb->users);
+
+		ret = dev_queue_xmit(pkt_dev->skb);
+		switch (ret) {
+		case NET_XMIT_SUCCESS:
+			pkt_dev->sofar++;
+			pkt_dev->seq_num++;
+			pkt_dev->tx_bytes += pkt_dev->last_pkt_size;
+			break;
+		case NET_XMIT_DROP:
+		case NET_XMIT_CN:
+		/* These are all valid return codes for a qdisc but
+		 * indicate packets are being dropped or will likely
+		 * be dropped soon.
+		 */
+		case NETDEV_TX_BUSY:
+		/* qdisc may call dev_hard_start_xmit directly in cases
+		 * where no queues exist e.g. loopback device, virtual
+		 * devices, etc. In this case we need to handle
+		 * NETDEV_TX_ codes.
+		 */
+		default:
+			pkt_dev->errors++;
+			net_info_ratelimited("%s xmit error: %d\n",
+					     pkt_dev->odevname, ret);
+			break;
+		}
+		goto out;
 	}
 
 	txq = skb_get_tx_queue(odev, pkt_dev->skb);

@@ -0,0 +1,66 @@
+#!/bin/bash
+#
+# Benchmark script:
+#  - developed for benchmarking egress qdisc path, derived (more
+#    like cut'n'pasted) from ingress benchmark script.
+#
+# Script for injecting packets into egress qdisc path of the stack
+# with pktgen "xmit_mode queue_xmit".
+#
+basedir=`dirname $0`
+source ${basedir}/functions.sh
+root_check_run_with_sudo "$@"
+
+# Parameter parsing via include
+source ${basedir}/parameters.sh
+[ -z "$DEST_IP" ] && DEST_IP="198.18.0.42"
+[ -z "$DST_MAC" ] && DST_MAC="90:e2:ba:ff:ff:ff"
+
+# Burst greater than 1 are invalid for queue_xmit mode
+if [[ -n "$BURST" ]]; then
+    err 1 "Bursting not supported for this mode"
+fi
+
+# Base Config
+DELAY="0"        # Zero means max speed
+COUNT="10000000" # Zero means indefinitely
+
+# General cleanup everything since last run
+pg_ctrl "reset"
+
+# Threads are specified with parameter -t value in $THREADS
+for ((thread = 0; thread < $THREADS; thread++)); do
+    # The device name is extended with @name, using thread number to
+    # make then unique, but any name will do.
+    dev=${DEV}@${thread}
+
+    # Add remove all other devices and add_device $dev to thread
+    pg_thread $thread "rem_device_all"
+    pg_thread $thread "add_device" $dev
+
+    # Base config of dev
+    pg_set $dev "flag QUEUE_MAP_CPU"
+    pg_set $dev "count $COUNT"
+    pg_set $dev "pkt_size $PKT_SIZE"
+    pg_set $dev "delay $DELAY"
+    pg_set $dev "flag NO_TIMESTAMP"
+
+    # Destination
+    pg_set $dev "dst_mac $DST_MAC"
+    pg_set $dev "dst $DEST_IP"
+
+    # Inject packet into TX qdisc egress path of stack
+    pg_set $dev "xmit_mode queue_xmit"
+done
+
+# start_run
+echo "Running... ctrl^C to stop" >&2
+pg_ctrl "start"
+echo "Done" >&2
+
+# Print results
+for ((thread = 0; thread < $THREADS; thread++)); do
+    dev=${DEV}@${thread}
+    echo "Device: $dev"
+    cat /proc/net/pktgen/$dev | grep -A2 "Result:"
+done