> bimerge only currently occurs in the kernel, where no amaps are
> involved.

Doesn't it occur theoretically, or just stat counter doesn't count up?

> entries involving amaps aren't forward (or bi) merged, only possibly
> back merged.

I can read the code that forwared merge won't occur if next entry has
amap, but can't find the code to inhibit bimerge when prev_entry has
amap.

enami.
Index: uvm_map.c
===================================================================
RCS file: /cvsroot/syssrc/sys/uvm/uvm_map.c,v
retrieving revision 1.121
diff -u -r1.121 uvm_map.c
--- uvm_map.c	2002/10/18 13:18:42	1.121
+++ uvm_map.c	2002/10/24 13:35:58
@@ -776,11 +776,10 @@
 				UVMCNT_DECR(map_kbackmerge);
 				UVMCNT_INCR(map_kbimerge);
 			} else {
-				UVMCNT_DECR(map_kbackmerge);
-				UVMCNT_INCR(map_kbimerge);
+				UVMCNT_DECR(map_ubackmerge);
+				UVMCNT_INCR(map_ubimerge);
 			}
-		}
-		else {
+		} else {
 			if (kmap)
 				UVMCNT_INCR(map_kforwmerge);
 			else