PERFORCE change 137400 for review

[Robert Watson]

http://perforce.freebsd.org/chv.cgi?CH=137400

Change 137400 by rwatson at rwatson_cinnamon on 2008/03/11 14:44:35

	Attempt to clarify the setup checks being done a little more.

Affected files ...

.. //depot/projects/zcopybpf/src/sys/net/bpf_zerocopy.c#32 edit

Differences ...

==== //depot/projects/zcopybpf/src/sys/net/bpf_zerocopy.c#32 (text+ko) ====

@@ -479,7 +479,8 @@
 	}
 
 	/*
-	 * Perform atomic check-and-exchange.
+	 * We only allow buffers to be installed once, so atomically check
+	 * that no buffers are currently installed and install new buffers.
 	 */
 	BPFD_LOCK(d);
 	if (d->bd_hbuf != NULL || d->bd_sbuf != NULL || d->bd_fbuf != NULL ||