netif_wake_queue wrong was Re: [PATCH] NFS Server performance and 8139too

[Andi Kleen]

On Sun, May 13, 2001 at 11:32:00AM +0400, Oleg Makarenko wrote:
> Beware that I am not a kernel hacker so the patch can be completely 
> wrong. But I hope it still can provide some useful information to 
> somebody  who really knows what is going on here :)

The problem is that the netif_wake_queue() 2.4 compatibility macro that
was recently added to 2.2 was wrong. It should do a mark_bh(). 8139too
uses the 2.4 macros, and therefore the netbh was always scheduled for too
late and performance was bad.

This patch should fix all drivers that use the new framework.

--- linux/include/linux/kcomp.h	Tue Dec 19 17:57:30 2000
+++ linux-work/include/linux/kcomp.h	Sun May 13 13:01:11 2001
@@ -17,7 +17,7 @@
 
 #define	net_device			device
 #define dev_kfree_skb_irq(a)		dev_kfree_skb(a)
-#define netif_wake_queue(dev)		clear_bit(0, &dev->tbusy)
+#define netif_wake_queue(dev)		do { clear_bit(0, &dev->tbusy); mark_bh(NET_BH); } while(0)
 #define netif_stop_queue(dev)		set_bit(0, &dev->tbusy)
 #define netif_start_queue(dev)		do { dev->tbusy = 0; dev->interrupt = 0; dev->start = 1; } while (0)
 #define netif_queue_stopped(dev)	dev->tbusy

-Andi