- change the buffer size from a constant to a

  TUNABLE variable (hw.netmap.buf_size) so we can experiment
  with values different from 2048 which may give better cache performance.

- rearrange the memory allocation code so it will be easier
  to replace it with a different implementation. The current code
  relies on a single large contiguous chunk of memory obtained through
  contigmalloc.
  The new implementation (not committed yet) uses multiple
  smaller chunks which are easier to fit in a fragmented address
  space.

2 files changed, 1 insertions, 13 deletions

diff --git a/sys/net/netmap.h b/sys/net/netmap.h
index 4dec1fd..0ba1537 100644
--- a/sys/net/netmap.h
+++ b/sys/net/netmap.h
@@ -258,12 +258,6 @@ struct nmreq {
 #define NETMAP_RING_MASK 0xfff		/* the ring number */
 };
 
-/*
- * default buf size is 2048, but it may make sense to have
- * it shorter for better cache usage.
- */
-
-#define	NETMAP_BUF_SIZE	(2048)
 #define NIOCGINFO	_IOWR('i', 145, struct nmreq) /* return IF info */
 #define NIOCREGIF	_IOWR('i', 146, struct nmreq) /* interface register */
 #define NIOCUNREGIF	_IO('i', 147) /* interface unregister */
diff --git a/sys/net/netmap_user.h b/sys/net/netmap_user.h
index c9443b8..6449045 100644
--- a/sys/net/netmap_user.h
+++ b/sys/net/netmap_user.h
@@ -73,14 +73,8 @@
 	((struct netmap_ring *)((char *)(nifp) +	\
 	    (nifp)->ring_ofs[index + (nifp)->ni_num_queues+1] ) )
 
-#if NETMAP_BUF_SIZE != 2048
-#error cannot handle odd size
 #define NETMAP_BUF(ring, index)				\
-	((char *)(ring) + (ring)->buf_ofs + ((index)*NETMAP_BUF_SIZE))
-#else
-#define NETMAP_BUF(ring, index)				\
-	((char *)(ring) + (ring)->buf_ofs + ((index)<<11))
-#endif
+	((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size))
 
 #define	NETMAP_RING_NEXT(r, i)				\
 	((i)+1 == (r)->num_slots ? 0 : (i) + 1 )