diff --git a/mps/src/buffer.c b/mps/src/buffer.c
index 24b549fc18f..55bcefeb858 100644
--- a/mps/src/buffer.c
+++ b/mps/src/buffer.c
@@ -1,6 +1,6 @@
 /* impl.c.buffer: ALLOCATION BUFFER IMPLEMENTATION
  *
- * $HopeName: MMsrc!buffer.c(trunk.61) $
+ * $HopeName: MMsrc!buffer.c(trunk.62) $
  * Copyright (C) 2000 Harlequin Limited.  All rights reserved.
  *
  * .purpose: This is (part of) the implementation of allocation buffers.
@@ -26,7 +26,7 @@
 
 #include "mpm.h"
 
-SRCID(buffer, "$HopeName: MMsrc!buffer.c(trunk.61) $");
+SRCID(buffer, "$HopeName: MMsrc!buffer.c(trunk.62) $");
 
 
 /* forward declarations */
@@ -334,12 +334,12 @@ void BufferDetach(Buffer buffer, Pool pool)
     buffer->emptySize += spare;
     if (buffer->isMutator) {
       buffer->pool->emptyMutatorSize += spare;
-      buffer->arena->emptyMutatorSize += spare;
-      buffer->arena->allocMutatorSize +=
+      ArenaGlobals(buffer->arena)->emptyMutatorSize += spare;
+      ArenaGlobals(buffer->arena)->allocMutatorSize +=
         AddrOffset(buffer->base, init);
     } else {
       buffer->pool->emptyInternalSize += spare;
-      buffer->arena->emptyInternalSize += spare;
+      ArenaGlobals(buffer->arena)->emptyInternalSize += spare;
     }
 
     /* Reset the buffer. */
@@ -661,13 +661,13 @@ void BufferAttach(Buffer buffer, Addr base, Addr limit,
   if (buffer->isMutator) {
     if (base != init) { /* see design.mps.buffer.count.alloc.how */
       Size prealloc = AddrOffset(base, init);
-      buffer->arena->allocMutatorSize -= prealloc;
+      ArenaGlobals(buffer->arena)->allocMutatorSize -= prealloc;
     }
     buffer->pool->fillMutatorSize += filled;
-    buffer->arena->fillMutatorSize += filled;
+    ArenaGlobals(buffer->arena)->fillMutatorSize += filled;
   } else {
     buffer->pool->fillInternalSize += filled;
-    buffer->arena->fillInternalSize += filled;
+    ArenaGlobals(buffer->arena)->fillInternalSize += filled;
   }
 
   /* run any class-specific attachment method */
diff --git a/mps/src/pool.c b/mps/src/pool.c
index 8b74fba50d1..b02f41f638b 100644
--- a/mps/src/pool.c
+++ b/mps/src/pool.c
@@ -1,6 +1,6 @@
 /* impl.c.pool: POOL IMPLEMENTATION
  *
- * $HopeName: MMsrc!pool.c(trunk.74) $
+ * $HopeName: MMsrc!pool.c(trunk.75) $
  * Copyright (C) 2001 Harlequin Limited.  All rights reserved.
  *
  * DESIGN
@@ -31,7 +31,7 @@
 
 #include "mpm.h"
 
-SRCID(pool, "$HopeName: MMsrc!pool.c(trunk.74) $");
+SRCID(pool, "$HopeName: MMsrc!pool.c(trunk.75) $");
 
 
 /* PoolClassCheck -- check a pool class */
@@ -300,7 +300,7 @@ Res PoolAlloc(Addr *pReturn, Pool pool, Size size,
   /* All PoolAllocs should advance the allocation clock, so we count */
   /* it all in the fillMutatorSize field. */
   pool->fillMutatorSize += size;
-  PoolArena(pool)->fillMutatorSize += size;
+  ArenaGlobals(PoolArena(pool))->fillMutatorSize += size;
 
   EVENT_PAW(PoolAlloc, pool, *pReturn, size);
 
@@ -540,6 +540,12 @@ Bool PoolFormat(Format *formatReturn, Pool pool)
 }
 
 
+/* PoolOfAddr -- return the pool containing the given address
+ *
+ * If the address points to a page assigned to a pool, this returns TRUE
+ * and sets *poolReturn to that pool.  Otherwise, it returns FALSE, and
+ * *poolReturn is unchanged. */
+
 Bool PoolOfAddr(Pool *poolReturn, Arena arena, Addr addr)
 {
   Tract tract;
@@ -568,10 +574,3 @@ Bool PoolHasAddr(Pool pool, Addr addr)
   managed = PoolOfAddr(&addrPool, arena, addr);
   return (managed && addrPool == pool);
 }
-
-
-double PoolMutatorAllocSize(Pool pool)
-{
-  AVERT(Pool, pool);
-  return pool->fillMutatorSize - pool->emptyMutatorSize;
-}
diff --git a/mps/src/walk.c b/mps/src/walk.c
index a5d87a6444a..9a3bd0122e3 100644
--- a/mps/src/walk.c
+++ b/mps/src/walk.c
@@ -1,13 +1,13 @@
 /* impl.c.walk: OBJECT WALKER
  *
- * $HopeName: MMsrc!walk.c(trunk.5) $
+ * $HopeName: MMsrc!walk.c(trunk.6) $
  * Copyright (C) 2001 Harlequin Limited.  All rights reserved.
  */
 
 #include "mpm.h"
 #include "mps.h"
 
-SRCID(walk, "$HopeName: MMsrc!walk.c(trunk.5) $");
+SRCID(walk, "$HopeName: MMsrc!walk.c(trunk.6) $");
 
 
 /* Heap Walking
@@ -354,7 +354,7 @@ void mps_arena_roots_walk(mps_arena_t mps_arena, mps_roots_stepper_t f,
   AVER(FUNCHECK(f));
   /* p and s are arbitrary closures, hence can't be checked */
 
-  AVER(arena->clamped);                /* .assume.parked */
+  AVER(ArenaGlobals(arena)->clamped);          /* .assume.parked */
   AVER(arena->busyTraces == TraceSetEMPTY);    /* .assume.parked */
 
   res = ArenaRootsWalk(ArenaGlobals(arena), f, p, s);