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From: Stephen Hemminger <shemminger@vyatta.com>
To: David Miller <davem@davemloft.net>,
	Robert Olsson <robert.olsson@its.uu.se>
Cc: netdev@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 05/14] pktgen: xmit logic reorganization
Date: Thu, 27 Aug 2009 16:55:11 -0700	[thread overview]
Message-ID: <20090827235705.493721319@vyatta.com> (raw)
In-Reply-To: 20090827235506.624381734@vyatta.com

[-- Attachment #1: pktgen-reorg1.patch --]
[-- Type: text/plain, Size: 3236 bytes --]

Do some reorganization of transmit logic path:
   * move transmit queue full idle to separate routine
   * add a cpu_relax()
   * eliminate some of the uneeded goto's
   * if queue is still stopped, go back to main thread loop.
   * don't give up transmitting if quantum is exhausted (be greedy)

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>


---
 net/core/pktgen.c |   55 +++++++++++++++++++++++-------------------------------
 1 file changed, 24 insertions(+), 31 deletions(-)

--- a/net/core/pktgen.c	2009-08-27 11:35:23.959966151 -0700
+++ b/net/core/pktgen.c	2009-08-27 11:57:10.525500312 -0700
@@ -3339,6 +3339,18 @@ static void pktgen_rem_thread(struct pkt
 	mutex_unlock(&pktgen_thread_lock);
 }
 
+static void idle(struct pktgen_dev *pkt_dev)
+{
+	u64 idle_start = getCurUs();
+
+	if (need_resched())
+		schedule();
+	else
+		cpu_relax();
+
+	pkt_dev->idle_acc += getCurUs() - idle_start;
+}
+
 static void pktgen_xmit(struct pktgen_dev *pkt_dev)
 {
 	struct net_device *odev = pkt_dev->odev;
@@ -3361,7 +3373,7 @@ static void pktgen_xmit(struct pktgen_de
 		if (pkt_dev->delay_us == 0x7FFFFFFF) {
 			pkt_dev->next_tx_us = getCurUs() + pkt_dev->delay_us;
 			pkt_dev->next_tx_ns = pkt_dev->delay_ns;
-			goto out;
+			return;
 		}
 	}
 
@@ -3373,26 +3385,14 @@ static void pktgen_xmit(struct pktgen_de
 	}
 
 	txq = netdev_get_tx_queue(odev, queue_map);
-	if (netif_tx_queue_stopped(txq) ||
-	    netif_tx_queue_frozen(txq) ||
-	    need_resched()) {
-		u64 idle_start = getCurUs();
-
-		if (!netif_running(odev)) {
+	/* Did we saturate the queue already? */
+	if (netif_tx_queue_stopped(txq) || netif_tx_queue_frozen(txq)) {
+		/* If device is down, then all queues are permnantly frozen */
+		if (netif_running(odev))
+			idle(pkt_dev);
+		else
 			pktgen_stop_device(pkt_dev);
-			goto out;
-		}
-		if (need_resched())
-			schedule();
-
-		pkt_dev->idle_acc += getCurUs() - idle_start;
-
-		if (netif_tx_queue_stopped(txq) ||
-		    netif_tx_queue_frozen(txq)) {
-			pkt_dev->next_tx_us = getCurUs();	/* TODO */
-			pkt_dev->next_tx_ns = 0;
-			goto out;	/* Try the next interface */
-		}
+		return;
 	}
 
 	if (pkt_dev->last_ok || !pkt_dev->skb) {
@@ -3407,7 +3407,7 @@ static void pktgen_xmit(struct pktgen_de
 				       "allocate skb in fill_packet.\n");
 				schedule();
 				pkt_dev->clone_count--;	/* back out increment, OOM */
-				goto out;
+				return;
 			}
 			pkt_dev->allocated_skbs++;
 			pkt_dev->clone_count = 0;	/* reset counter */
@@ -3419,9 +3419,9 @@ static void pktgen_xmit(struct pktgen_de
 	txq = netdev_get_tx_queue(odev, queue_map);
 
 	__netif_tx_lock_bh(txq);
-	if (!netif_tx_queue_stopped(txq) &&
-	    !netif_tx_queue_frozen(txq)) {
-
+	if (unlikely(netif_tx_queue_stopped(txq) || netif_tx_queue_frozen(txq)))
+		pkt_dev->last_ok = 0;
+	else {
 		atomic_inc(&(pkt_dev->skb->users));
 	      retry_now:
 		ret = (*xmit)(pkt_dev->skb, odev);
@@ -3458,13 +3458,6 @@ static void pktgen_xmit(struct pktgen_de
 			pkt_dev->next_tx_ns -= 1000;
 		}
 	}
-
-	else {			/* Retry it next time */
-		pkt_dev->last_ok = 0;
-		pkt_dev->next_tx_us = getCurUs();	/* TODO */
-		pkt_dev->next_tx_ns = 0;
-	}
-
 	__netif_tx_unlock_bh(txq);
 
 	/* If pkt_dev->count is zero, then run forever */

-- 


  parent reply	other threads:[~2009-08-27 23:59 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-27 23:55 [PATCH 00/14] pktgen update for net-next (2.6.32) Stephen Hemminger
2009-08-27 23:55 ` [PATCH 01/14] pktgen: minor cleanup Stephen Hemminger
2009-08-27 23:55 ` [PATCH 02/14] pktgen: change inlining Stephen Hemminger
2009-08-27 23:55 ` [PATCH 03/14] pktgen: mark read-only/mostly variables Stephen Hemminger
2009-08-27 23:55 ` [PATCH 04/14] pktgen: stop_device cleanup Stephen Hemminger
2009-08-27 23:55 ` Stephen Hemminger [this message]
2009-08-27 23:55 ` [PATCH 06/14] pktgen: cleanup clone count test Stephen Hemminger
2009-08-27 23:55 ` [PATCH 07/14] pktgen: use netdev_alloc_skb Stephen Hemminger
2009-08-27 23:55 ` [PATCH 08/14] pktgen: reorganize transmit loop Stephen Hemminger
2009-08-28  3:52   ` Ben Greear
2009-08-28  5:49     ` Stephen Hemminger
2009-08-28 16:01       ` Ben Greear
2009-08-29  6:04       ` David Miller
2009-09-01 21:30         ` Stephen Hemminger
2009-09-02 13:06           ` Patrick McHardy
2009-08-27 23:55 ` [PATCH 09/14] pktgen: avoid calling gettimeofday Stephen Hemminger
2009-08-27 23:55 ` [PATCH 10/14] pktgen: convert to use ktime_t Stephen Hemminger
2009-08-27 23:55 ` [PATCH 11/14] pktgen: spin using hrtimer Stephen Hemminger
2009-08-27 23:55 ` [PATCH 12/14] pktgen: use common idle routine Stephen Hemminger
2009-08-27 23:55 ` [PATCH 13/14] pktgen: cleanup checkpatch warnings Stephen Hemminger
2009-08-27 23:55 ` [PATCH 14/14] pktgen: increase version Stephen Hemminger
2009-08-29  6:33 ` [PATCH 00/14] pktgen update for net-next (2.6.32) David Miller
2009-08-29  6:42   ` David Miller
2009-09-08 11:52 ` robert
2009-09-08 12:21   ` Jesper Dangaard Brouer
2009-09-08 15:41     ` robert
2009-09-09  7:53       ` Jesper Dangaard Brouer
2009-09-11 14:29         ` Jesper Dangaard Brouer

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