PERFORCE change 95433 for review

[tkuik]

http://perforce.freebsd.org/chv.cgi?CH=95433

Change 95433 by tkuik at tkuik_freebsd on 2006/04/17 18:58:32

	Added memory barrier definitions; fixes networking lock-up
	Submitted by:	Tim Kuik

Affected files ...

.. //depot/projects/xen3/src/sys/i386-xen/include/xen-os.h#4 edit

Differences ...

==== //depot/projects/xen3/src/sys/i386-xen/include/xen-os.h#4 (text+ko) ====

@@ -148,9 +148,9 @@
 #define spin_unlock_irqrestore mtx_unlock_irqrestore
 
 
-#define mb()
-#define rmb()
-#define wmb()
+#define mb() __asm__ __volatile__("lock; addl $0, 0(%%esp)": : :"memory")
+#define rmb() mb()
+#define wmb() barrier()
 #ifdef SMP
 #define smp_mb() mb() 
 #define smp_rmb() rmb()