PERFORCE change 131556 for review

[Robert Watson]

http://perforce.freebsd.org/chv.cgi?CH=131556

Change 131556 by rwatson at rwatson_cinnamon on 2007/12/24 22:53:47

	Remove memory barrier/atomic XXX's, since that is now addressed.

Affected files ...

.. //depot/projects/zcopybpf/src/sys/net/bpf_zerocopy.c#26 edit

Differences ...

==== //depot/projects/zcopybpf/src/sys/net/bpf_zerocopy.c#26 (text+ko) ====

@@ -339,11 +339,6 @@
  * Notification from the BPF framework that a buffer has moved into the held
  * slot on a descriptor.  Zero-copy BPF will update the shared page to let
  * the user process know.
- *
- * XXXRW: Do we need to use a memory barrier, atomic operation, or the like
- * to make sure that the generation update is the last write to make it out
- * after any packet date so that user space sees the generation increase only
- * at or after the last packet data change?
  */
 void
 bpf_zerocopy_bufheld(struct bpf_d *d)
@@ -364,8 +359,6 @@
  * held position can be moved to the free position, which can be indicated by
  * the user process making their generation number equal to the kernel
  * generation number.
- *
- * XXXRW: Memory ordering also an issue here?
  */
 int
 bpf_zerocopy_canfreebuf(struct bpf_d *d)