diff --git a/drd/Makefile.am b/drd/Makefile.am
index fd63505..153b384 100644
--- a/drd/Makefile.am
+++ b/drd/Makefile.am
@@ -54,7 +54,6 @@
 
 DRD_SOURCES_COMMON =    \
   drd_barrier.c         \
-  drd_bitmap2_node.c    \
   drd_clientobj.c       \
   drd_clientreq.c       \
   drd_cond.c            \
diff --git a/drd/drd_bitmap.c b/drd/drd_bitmap.c
index afd3654..d7e4f91 100644
--- a/drd/drd_bitmap.c
+++ b/drd/drd_bitmap.c
@@ -45,6 +45,7 @@
 
 /* Local variables. */
 
+static OSet* s_bm2_set_template;
 static ULong s_bitmap_creation_count;
 static ULong s_bitmap_merge_count;
 static ULong s_bitmap2_merge_count;
@@ -52,6 +53,21 @@
 
 /* Function definitions. */
 
+void DRD_(bm_module_init)(void)
+{
+   tl_assert(!s_bm2_set_template);
+   s_bm2_set_template
+      = VG_(OSetGen_Create_With_Pool)(0, 0, VG_(malloc), "drd.bitmap.bn.2",
+                                      VG_(free), 512, sizeof(struct bitmap2));
+}
+
+void DRD_(bm_module_cleanup)(void)
+{
+   tl_assert(s_bm2_set_template);
+   VG_(OSetGen_Destroy)(s_bm2_set_template);
+   s_bm2_set_template = NULL;
+}
+
 struct bitmap* DRD_(bm_new)()
 {
    struct bitmap* bm;
@@ -90,8 +106,7 @@
       bm->cache[i].a1  = ~(UWord)1;
       bm->cache[i].bm2 = 0;
    }
-   bm->oset = VG_(OSetGen_Create)(0, 0, DRD_(bm2_alloc_node),
-                                  "drd.bitmap.bn.2", DRD_(bm2_free_node));
+   bm->oset = VG_(OSetGen_EmptyClone)(s_bm2_set_template);
 
    s_bitmap_creation_count++;
 }
diff --git a/drd/drd_bitmap2_node.c b/drd/drd_bitmap2_node.c
deleted file mode 100644
index 3deb644..0000000
--- a/drd/drd_bitmap2_node.c
+++ /dev/null
@@ -1,177 +0,0 @@
-/*
-  This file is part of drd, a thread error detector.
-
-  Copyright (C) 2006-2011 Bart Van Assche <bvanassche@acm.org>.
-
-  This program is free software; you can redistribute it and/or
-  modify it under the terms of the GNU General Public License as
-  published by the Free Software Foundation; either version 2 of the
-  License, or (at your option) any later version.
-
-  This program is distributed in the hope that it will be useful, but
-  WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with this program; if not, write to the Free Software
-  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
-  02111-1307, USA.
-
-  The GNU General Public License is contained in the file COPYING.
-*/
-
-/*
- * Block allocator for second-level bitmap nodes. Each node consists of
- * an OSetGen node and a struct bitmap2. The code below allocates
- * NODES_PER_CHUNK nodes at a time.
- */
-
-
-#include "drd_basics.h"           /* DRD_() */
-#include "drd_bitmap.h"           /* struct bitmap2 */
-#include "pub_drd_bitmap.h"
-#include "pub_tool_basics.h"      /* Addr, SizeT */
-#include "pub_tool_libcassert.h"  /* tl_assert() */
-#include "pub_tool_libcbase.h"    /* VG_ROUNDUP() */
-#include "pub_tool_libcprint.h"   /* VG_(message)() */
-#include "pub_tool_mallocfree.h"  /* VG_(malloc), VG_(free) */
-
-
-#define NODES_PER_CHUNCK 512
-
-
-/* Local type definitions. */
-
-struct block_allocator_chunk {
-   struct block_allocator_chunk* next;
-   struct block_allocator_chunk* prev;
-   int   nallocated;
-   void* data;
-   void* data_end;
-   void* first_free;
-};
-
-
-/* Local variables. */
-
-static SizeT s_root_node_size;
-static SizeT s_bm2_node_size;
-static struct block_allocator_chunk* s_first;
-
-
-/* Function definitions. */
-
-/**
- * Allocate a new chunk and insert it at the start of the doubly-linked list
- * s_first.
- */
-static struct block_allocator_chunk* allocate_new_chunk(void)
-{
-   struct block_allocator_chunk* p;
-   int i;
-
-   tl_assert(s_bm2_node_size > 0);
-
-   p = VG_(malloc)("drd.bitmap.bac",
-                   sizeof(*p) + NODES_PER_CHUNCK * s_bm2_node_size);
-   tl_assert(p);
-   p->next = s_first;
-   if (s_first)
-      p->next->prev = p;
-   s_first = p;
-   p->prev = 0;
-   p->nallocated = 0;
-   p->data = (char*)p + sizeof(*p);
-   tl_assert(p->data);
-   p->data_end = (char*)(p->data) + NODES_PER_CHUNCK * s_bm2_node_size;
-   p->first_free = p->data;
-   for (i = 0; i < NODES_PER_CHUNCK - 1; i++)
-   {
-      *(void**)((char*)(p->data) + i * s_bm2_node_size)
-         = (char*)(p->data) + (i + 1) * s_bm2_node_size;
-   }
-   tl_assert(i == NODES_PER_CHUNCK - 1);
-   *(void**)((char*)(p->data) + i * s_bm2_node_size) = NULL;
-
-   return p;
-}
-
-/** Free a chunk and remove it from the list of chunks. */
-static void free_chunk(struct block_allocator_chunk* const p)
-{
-   tl_assert(p);
-   tl_assert(p->nallocated == 0);
-
-   if (p == s_first)
-      s_first = p->next;
-   else if (p->prev)
-      p->prev->next = p->next;
-   if (p->next)
-      p->next->prev = p->prev;
-   VG_(free)(p);
-}
-
-/** Allocate a node. */
-void* DRD_(bm2_alloc_node)(HChar* const ec, const SizeT szB)
-{
-   /*
-    * If szB < sizeof(struct bitmap2) then this function has been called to
-    * allocate an AVL tree root node. Otherwise it has been called to allocate
-    * an AVL tree branch or leaf node.
-    */
-   if (s_root_node_size == 0)
-      s_root_node_size = szB;
-   if (szB == s_root_node_size)
-      return VG_(malloc)(ec, szB);
-
-   while (True)
-   {
-      struct block_allocator_chunk* p;
-
-      if (s_bm2_node_size == 0)
-         s_bm2_node_size = szB;
-      else
-         tl_assert(s_bm2_node_size == szB);
-
-      for (p = s_first; p; p = p->next)
-      {
-         if (p->first_free)
-         {
-            void* result;
-
-            p->nallocated++;
-            result = p->first_free;
-            p->first_free = *(void**)(p->first_free);
-            return result;
-         }
-      }
-
-      allocate_new_chunk();
-   }
-}
-
-/** Free a node. */
-void  DRD_(bm2_free_node)(void* const bm2)
-{
-   struct block_allocator_chunk* p;
-
-   tl_assert(bm2);
-
-   if (s_bm2_node_size > 0) {
-      for (p = s_first; p; p = p->next) {
-	 if (p->data <= bm2 && bm2 < p->data_end) {
-	    /* Free a non-root AVL tree node. */
-	    tl_assert(((char*)bm2 - (char*)(p->data)) % s_bm2_node_size == 0);
-	    *(void**)bm2 = p->first_free;
-	    p->first_free = bm2;
-	    tl_assert(p->nallocated >= 1);
-	    if (--(p->nallocated) == 0)
-	       free_chunk(p);
-	    return;
-	 }
-      }
-   }
-   /* Free the memory that was allocated for an AVL tree root node. */
-   VG_(free)(bm2);
-}
diff --git a/drd/drd_main.c b/drd/drd_main.c
index 815b5a2..de8613c 100644
--- a/drd/drd_main.c
+++ b/drd/drd_main.c
@@ -758,6 +758,8 @@
                    DRD_(get_mutex_lock_count)());
       DRD_(print_malloc_stats)();
    }
+
+   DRD_(bm_module_cleanup)();
 }
 
 static
@@ -810,6 +812,8 @@
    DRD_(register_malloc_wrappers)(drd_start_using_mem_w_ecu,
                                   drd_stop_using_nonstack_mem);
 
+   DRD_(bm_module_init)();
+
    DRD_(clientreq_init)();
 
    DRD_(suppression_init)();
diff --git a/drd/pub_drd_bitmap.h b/drd/pub_drd_bitmap.h
index 68b5707..b0981ec 100644
--- a/drd/pub_drd_bitmap.h
+++ b/drd/pub_drd_bitmap.h
@@ -75,6 +75,8 @@
 
 /* Function declarations. */
 
+void DRD_(bm_module_init)(void);
+void DRD_(bm_module_cleanup)(void);
 struct bitmap* DRD_(bm_new)(void);
 void DRD_(bm_delete)(struct bitmap* const bm);
 void DRD_(bm_init)(struct bitmap* const bm);
@@ -148,7 +150,4 @@
 ULong DRD_(bm_get_bitmap2_creation_count)(void);
 ULong DRD_(bm_get_bitmap2_merge_count)(void);
 
-void* DRD_(bm2_alloc_node)(HChar* const ec, const SizeT szB);
-void  DRD_(bm2_free_node)(void* const bm2);
-
 #endif /* __PUB_DRD_BITMAP_H */
diff --git a/drd/tests/unit_bitmap.c b/drd/tests/unit_bitmap.c
index 891d4e2..b64c496 100644
--- a/drd/tests/unit_bitmap.c
+++ b/drd/tests/unit_bitmap.c
@@ -11,7 +11,6 @@
 #include "coregrind/m_poolalloc.c"
 #include "coregrind/m_oset.c"
 #include "drd/drd_bitmap.c"
-#include "drd/drd_bitmap2_node.c"
 #include "drd/pub_drd_bitmap.h"
 
 
@@ -344,9 +343,11 @@
 
   fprintf(stderr, "Start of DRD BM unit test.\n");
 
+  DRD_(bm_module_init)();
   bm_test1();
   bm_test2();
   bm_test3(outer_loop_step, inner_loop_step);
+  DRD_(bm_module_cleanup)();
 
   fprintf(stderr, "End of DRD BM unit test.\n");