mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Stephen Hemminger <shemminger@osdl.org>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] netpoll: retry logic cleanup
Date: Fri, 20 Oct 2006 15:35:09 -0700	[thread overview]
Message-ID: <20061020153509.228c7103@dxpl.pdx.osdl.net> (raw)
In-Reply-To: <20061020.140149.125893169.davem@davemloft.net>

Change retry logic of netpoll.  Always requeue if unable to send
instead of dropping. Make retry counter per send rather than causing
mass migration when tries gets less than zero. Since callers are
either netpoll_send_arp or netpoll_send_udp, we knwo that np and np->dev
can't be null.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>


--- netpoll.orig/include/linux/netpoll.h
+++ netpoll/include/linux/netpoll.h
@@ -27,7 +27,6 @@ struct netpoll {
 struct netpoll_info {
 	spinlock_t poll_lock;
 	int poll_owner;
-	int tries;
 	int rx_flags;
 	spinlock_t rx_lock;
 	struct netpoll *rx_np; /* netpoll that registered an rx_hook */
--- netpoll.orig/net/core/netpoll.c
+++ netpoll/net/core/netpoll.c
@@ -232,50 +232,43 @@ static struct sk_buff * find_skb(struct 
 
 static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 {
-	int status;
-	struct netpoll_info *npinfo;
-
-	if (!np || !np->dev || !netif_running(np->dev))
-		goto free_skb;
+	struct net_device *dev = np->dev;
+	struct netpoll_info *npinfo = dev->npinfo;
+	int status, tries;
 
-	npinfo = np->dev->npinfo;
+	if (!netif_running(dev) || !netif_device_present(dev))
+		__kfree_skb(skb);
 
 	/* avoid recursion */
 	if (npinfo->poll_owner == smp_processor_id() ||
-	    np->dev->xmit_lock_owner == smp_processor_id()) {
-		if (np->drop)
-			np->drop(skb);
-		else
-			__kfree_skb(skb);
-		return;
-	}
-
-	do {
-		npinfo->tries--;
-		netif_tx_lock(np->dev);
+	    dev->xmit_lock_owner == smp_processor_id())
+		goto busy;
 
+	for (tries = MAX_RETRIES; tries; --tries) {
 		/*
 		 * network drivers do not expect to be called if the queue is
 		 * stopped.
 		 */
-		status = NETDEV_TX_BUSY;
-		if (!netif_queue_stopped(np->dev))
-			status = np->dev->hard_start_xmit(skb, np->dev);
-
-		netif_tx_unlock(np->dev);
+		if (netif_queue_stopped(dev))
+			status = NETDEV_TX_BUSY;
+		else
+			status = dev->hard_start_xmit(skb, dev);
+		netif_tx_unlock(dev);
 
 		/* success */
-		if(!status) {
-			npinfo->tries = MAX_RETRIES; /* reset */
+		if(status == NETDEV_TX_OK)
 			return;
-		}
 
 		/* transmit busy */
 		netpoll_poll(np);
 		udelay(50);
-	} while (npinfo->tries > 0);
-free_skb:
-	__kfree_skb(skb);
+	}
+
+busy:
+	if (np->drop)
+		np->drop(skb);
+	else
+		__kfree_skb(skb);
 }
 
 void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
@@ -628,7 +621,7 @@ int netpoll_setup(struct netpoll *np)
 		npinfo->rx_np = NULL;
 		spin_lock_init(&npinfo->poll_lock);
 		npinfo->poll_owner = -1;
-		npinfo->tries = MAX_RETRIES;
+
 		spin_lock_init(&npinfo->rx_lock);
 		skb_queue_head_init(&npinfo->arp_tx);
 	} else

  parent reply	other threads:[~2006-10-20 22:35 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-10-19 17:15 [PATCH 0/3] netpoll/netconsole fixes Stephen Hemminger
2006-10-19 17:15 ` [PATCH 1/3] netpoll: initialize skb for UDP Stephen Hemminger
2006-10-20  6:58   ` David Miller
2006-10-19 17:15 ` [PATCH 2/3] netpoll: rework skb transmit queue Stephen Hemminger
2006-10-20  7:15   ` David Miller
2006-10-20 15:18     ` Stephen Hemminger
2006-10-20 19:24       ` David Miller
2006-10-20 19:25         ` Stephen Hemminger
2006-10-20 19:52           ` David Miller
2006-10-20 20:14             ` Stephen Hemminger
2006-10-20 20:25             ` Stephen Hemminger
2006-10-21  5:00               ` Dave Jones
2006-10-21  6:38                 ` David Miller
2006-10-20 15:40     ` Stephen Hemminger
2006-10-20 19:27       ` David Miller
2006-10-20 19:31         ` Stephen Hemminger
2006-10-20 20:42       ` David Miller
2006-10-20 20:48         ` Stephen Hemminger
2006-10-20 21:01           ` Andi Kleen
2006-10-20 21:08             ` David Miller
2006-10-20 21:16               ` Andi Kleen
2006-10-20 21:41                 ` Stephen Hemminger
2006-10-20 21:01           ` David Miller
2006-10-20 22:30             ` [PATCH 1/3] netpoll: use sk_buff_head for txq Stephen Hemminger
2006-10-23  3:42               ` David Miller
     [not found]                 ` <20061023115337.1f636ffb@dxpl.pdx.osdl.net>
2006-10-23 19:02                   ` [PATCH 4/5] netpoll: move drop hook inline Stephen Hemminger
2006-10-23 19:03                   ` [PATCH 3/5] netpoll: cleanup transmit retry logic Stephen Hemminger
2006-10-23 19:02                 ` [PATCH 1/5] netpoll: use sk_buff_head for txq Stephen Hemminger
2006-10-23 19:04                   ` [PATCH 5/5] netpoll: interface cleanup Stephen Hemminger
2006-10-24  6:03                   ` [PATCH 1/5] netpoll: use sk_buff_head for txq David Miller
2006-10-24 14:51                     ` Stephen Hemminger
2006-10-24 14:14                       ` Stephen Hemminger
     [not found]                 ` <20061023115111.0d69846e@dxpl.pdx.osdl.net>
2006-10-23 19:02                   ` [PATCH 2/5] netpoll: cleanup queued transmit Stephen Hemminger
2006-10-20 22:32             ` [PATCH 2/3] netpoll: use device xmit directly Stephen Hemminger
2006-10-20 22:35             ` Stephen Hemminger [this message]
2006-10-19 17:15 ` [PATCH 3/3] netpoll: use skb_buff_head for skb cache Stephen Hemminger
2006-10-20  6:57 ` [PATCH 0/3] netpoll/netconsole fixes Andrew Morton
2006-10-20  7:16   ` David Miller

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20061020153509.228c7103@dxpl.pdx.osdl.net \
    --to=shemminger@osdl.org \
    --cc=davem@davemloft.net \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®