diff --git a/racket/src/racket/include/schthread.h b/racket/src/racket/include/schthread.h
index 574d653671..44cd9e4495 100644
--- a/racket/src/racket/include/schthread.h
+++ b/racket/src/racket/include/schthread.h
@@ -311,6 +311,7 @@ typedef struct Thread_Local_Variables {
   volatile short delayed_break_ready_;
   struct Scheme_Thread *main_break_target_thread_;
   intptr_t scheme_code_page_total_;
+  intptr_t scheme_code_total_;
   intptr_t max_gc_pre_used_bytes_;
   int num_major_garbage_collections_;
   int num_minor_garbage_collections_;
@@ -358,6 +359,7 @@ typedef struct Thread_Local_Variables {
   struct Scheme_Object *is_syntax_proc_;
   struct Scheme_Object *expander_syntax_to_datum_proc_;
   struct Scheme_Hash_Table *local_primitive_tables_;
+  struct Scheme_Object *current_linklet_native_lambdas_;
 } Thread_Local_Variables;
 
 #if defined(IMPLEMENT_THREAD_LOCAL_VIA_PTHREADS)
@@ -690,6 +692,7 @@ XFORM_GC_VARIABLE_STACK_THROUGH_THREAD_LOCAL;
 #define delayed_break_ready XOA (scheme_get_thread_local_variables()->delayed_break_ready_)
 #define main_break_target_thread XOA (scheme_get_thread_local_variables()->main_break_target_thread_)
 #define scheme_code_page_total XOA (scheme_get_thread_local_variables()->scheme_code_page_total_)
+#define scheme_code_total XOA (scheme_get_thread_local_variables()->scheme_code_total_)
 #define max_gc_pre_used_bytes XOA (scheme_get_thread_local_variables()->max_gc_pre_used_bytes_)
 #define num_major_garbage_collections XOA (scheme_get_thread_local_variables()->num_major_garbage_collections_)
 #define num_minor_garbage_collections XOA (scheme_get_thread_local_variables()->num_minor_garbage_collections_)
@@ -737,6 +740,7 @@ XFORM_GC_VARIABLE_STACK_THROUGH_THREAD_LOCAL;
 #define is_syntax_proc XOA (scheme_get_thread_local_variables()->is_syntax_proc_)
 #define expander_syntax_to_datum_proc XOA (scheme_get_thread_local_variables()->expander_syntax_to_datum_proc_)
 #define local_primitive_tables XOA (scheme_get_thread_local_variables()->local_primitive_tables_)
+#define current_linklet_native_lambdas XOA (scheme_get_thread_local_variables()->current_linklet_native_lambdas_)
 
 /* **************************************** */
 
diff --git a/racket/src/racket/src/env.c b/racket/src/racket/src/env.c
index 7b76871b2e..6f4d702a54 100644
--- a/racket/src/racket/src/env.c
+++ b/racket/src/racket/src/env.c
@@ -190,6 +190,7 @@ Scheme_Env *scheme_basic_env()
   scheme_init_validate();
 #ifdef MZ_USE_JIT
   scheme_init_jit();
+  scheme_init_jitprep();
 #endif
 
   scheme_init_process_globals();
diff --git a/racket/src/racket/src/jit.c b/racket/src/racket/src/jit.c
index 88f178c721..da16ee9c96 100644
--- a/racket/src/racket/src/jit.c
+++ b/racket/src/racket/src/jit.c
@@ -456,6 +456,8 @@ static Scheme_Object *extract_closure_local(int pos, mz_jit_state *jitter, int g
 {
   if (PAST_LIMIT()) return NULL;
 
+  if (!jitter->nc) return NULL;
+
   if (pos >= jitter->self_pos - jitter->self_to_closure_delta) {
     pos -= (jitter->self_pos - jitter->self_to_closure_delta);
     if (pos < jitter->nc->code->u2.orig_code->closure_size) {
@@ -493,6 +495,8 @@ Scheme_Object *scheme_specialize_to_constant(Scheme_Object *obj, mz_jit_state *j
 
   if (PAST_LIMIT()) return obj;
 
+  if (!jitter->nc) return obj;
+
   if (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED) {
     if (SAME_TYPE(SCHEME_TYPE(obj), scheme_local_type)) {
       c = scheme_extract_closure_local(obj, jitter, extra_push, 1);
@@ -1361,7 +1365,7 @@ static int generate_closure_fill(Scheme_Lambda *lam,
   for (j = 0; j < size; j++) {
     CHECK_LIMIT();
 
-    if (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED)
+    if (jitter->nc && (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED))
       v = extract_closure_local(map[j], jitter, 1);
     else
       v = NULL;
@@ -2116,7 +2120,7 @@ int scheme_generate(Scheme_Object *obj, mz_jit_state *jitter, int is_tail, int w
         START_JIT_DATA();
         LOG_IT(("top-level\n"));
         mz_rs_sync_fail_branch();
-        if (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED) {
+        if (jitter->nc && (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED)) {
           /* Must be a top-level that is not yet defined. */
           Scheme_Object *b;
           mz_rs_sync_fail_branch();
@@ -2271,7 +2275,7 @@ int scheme_generate(Scheme_Object *obj, mz_jit_state *jitter, int is_tail, int w
       START_JIT_DATA();
       LOG_IT(("unbox local\n"));
 
-      if (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED)
+      if (jitter->nc && (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED))
         specialized = scheme_extract_closure_local(obj, jitter, 0, 1);
 
       pos = mz_remap(SCHEME_LOCAL_POS(obj));
@@ -2996,7 +3000,7 @@ int scheme_generate(Scheme_Object *obj, mz_jit_state *jitter, int is_tail, int w
       if (lv->count == 1) {
 	/* Expect one result: */
         Scheme_Object *specialized = NULL;
-        if (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED)
+        if (jitter->nc && (SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED))
           specialized = extract_closure_local(lv->position, jitter, 1);
 	scheme_generate_non_tail(lv->value, jitter, 0, 1, 0); /* no sync */
 	CHECK_LIMIT();
@@ -3801,7 +3805,10 @@ static int do_generate_closure(mz_jit_state *jitter, void *_data)
   to_args = 0;
 #endif
 
-  specialized = SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED;
+  if (jitter->nc)
+    specialized = SCHEME_NATIVE_LAMBDA_FLAGS(jitter->nc->code) & NATIVE_SPECIALIZED;
+  else
+    specialized = 0;
 
   /* Extract closure to runstack: */
   cnt = lam->closure_size;
@@ -3970,9 +3977,9 @@ static int do_generate_closure(mz_jit_state *jitter, void *_data)
   return 1;
 }
 
-static void on_demand_generate_lambda(Scheme_Native_Closure *nc, int argc, Scheme_Object **argv, int argv_delta)
+static void on_demand_generate_lambda(Scheme_Native_Closure *nc, Scheme_Native_Lambda *nlam,
+                                      int argc, Scheme_Object **argv, int argv_delta)
 {
-  Scheme_Native_Lambda *nlam = nc->code;
   Scheme_Lambda *lam;
   Generate_Lambda gdata;
   void *start_code, *tail_code, *arity_code;
@@ -4065,7 +4072,7 @@ static void on_demand_generate_lambda(Scheme_Native_Closure *nc, int argc, Schem
 
 void scheme_on_demand_generate_lambda(Scheme_Native_Closure *nc, int argc, Scheme_Object **argv, int argv_delta)
 {
-  on_demand_generate_lambda(nc, argc, argv, argv_delta);
+  on_demand_generate_lambda(nc, nc->code, argc, argv, argv_delta);
 }
 
 Scheme_Object **scheme_on_demand_with_args(Scheme_Object **in_argv, Scheme_Object **argv, int argv_delta)
@@ -4087,6 +4094,12 @@ Scheme_Object **scheme_on_demand(Scheme_Object **rs)
   return scheme_on_demand_with_args(MZ_RUNSTACK, rs, 0);
 }
 
+void scheme_force_jit_generate(Scheme_Native_Lambda *nlam)
+{
+  if (nlam->start_code == scheme_on_demand_jit_code)
+    on_demand_generate_lambda(NULL, nlam, 0, NULL, 0);
+}
+
 static Scheme_Native_Lambda *create_native_lambda(Scheme_Lambda *lam, int clear_code_after_jit,
                                                   Scheme_Native_Lambda *case_lam)
 {
@@ -4121,11 +4134,6 @@ static Scheme_Native_Lambda *create_native_lambda(Scheme_Lambda *lam, int clear_
   nlam->max_let_depth = (JIT_RUNSTACK_RESERVE * sizeof(void*)) | (case_lam ? 0x2 : 0) | (clear_code_after_jit ? 0x1 : 0);
   nlam->tl_map = lam->tl_map;
 
-#if 0
-  /* Compile immediately: */
-  on_demand_generate_lambda(nlam);
-#endif
-
   return nlam;
 }
 
diff --git a/racket/src/racket/src/jitprep.c b/racket/src/racket/src/jitprep.c
index 807bed567d..d77afde166 100644
--- a/racket/src/racket/src/jitprep.c
+++ b/racket/src/racket/src/jitprep.c
@@ -33,8 +33,19 @@
 #include "schpriv.h"
 #include "schrunst.h"
 
+THREAD_LOCAL_DECL(static Scheme_Object *current_linklet_native_lambdas);
+static int force_jit;
+
 #ifdef MZ_USE_JIT
 
+void scheme_init_jitprep()
+{
+  REGISTER_SO(current_linklet_native_lambdas);
+
+  if (getenv("PLT_EAGER_JIT"))
+    force_jit = 1;
+}
+
 static Scheme_Object *jit_expr(Scheme_Object *expr);
 
 static Scheme_Object *jit_application(Scheme_Object *o)
@@ -434,6 +445,8 @@ Scheme_Object *scheme_case_lambda_jit(Scheme_Object *expr)
       ((Scheme_Lambda *)val)->name = name;
       if (((Scheme_Lambda *)val)->closure_size)
 	all_closed = 0;
+      if (current_linklet_native_lambdas)
+        current_linklet_native_lambdas = scheme_make_pair(val, current_linklet_native_lambdas);
     }
 
     /* Generating the code may cause empty closures to be formed: */
@@ -561,6 +574,10 @@ Scheme_Object *scheme_jit_closure(Scheme_Object *code, Scheme_Object *context)
     ndata = scheme_generate_lambda(data2, 1, NULL);
     data2->u.native_code = ndata;
 
+    if (current_linklet_native_lambdas)
+      current_linklet_native_lambdas = scheme_make_pair((Scheme_Object *)ndata,
+                                                        current_linklet_native_lambdas);
+
     if (!context)
       data->u.jit_clone = data2;
   }
@@ -664,6 +681,9 @@ Scheme_Linklet *scheme_jit_linklet(Scheme_Linklet *linklet, int step)
     return new_linklet;
   }
 
+  if (force_jit)
+    current_linklet_native_lambdas = scheme_null;
+
   i = SCHEME_VEC_SIZE(linklet->bodies);
   bodies = scheme_make_vector(i, NULL);
   while (i--) {
@@ -675,6 +695,9 @@ Scheme_Linklet *scheme_jit_linklet(Scheme_Linklet *linklet, int step)
 
   new_linklet->jit_ready = 2;
 
+  new_linklet->native_lambdas = current_linklet_native_lambdas;
+  current_linklet_native_lambdas = NULL;
+
   return new_linklet;
 }
 
diff --git a/racket/src/racket/src/linklet.c b/racket/src/racket/src/linklet.c
index fa90b73a1e..1f939af89d 100644
--- a/racket/src/racket/src/linklet.c
+++ b/racket/src/racket/src/linklet.c
@@ -1411,6 +1411,36 @@ static void *instantiate_linklet_k(void)
   if (!multi)
     v = scheme_check_one_value(v);
 
+  if (linklet->native_lambdas) {
+    int mc;
+    Scheme_Object **mv, *l;
+
+    if (SAME_OBJ(v, SCHEME_MULTIPLE_VALUES)) {
+      p = scheme_current_thread;
+      mv = p->ku.multiple.array;
+      mc = p->ku.multiple.count;
+      if (SAME_OBJ(mv, p->values_buffer))
+        p->values_buffer = NULL;
+    } else {
+      mv = NULL;
+      mc = 0;
+    }
+
+    l = linklet->native_lambdas;
+    linklet->native_lambdas = NULL;
+
+    while (SCHEME_PAIRP(l)) {
+      scheme_force_jit_generate((Scheme_Native_Lambda *)SCHEME_CAR(l));
+      l = SCHEME_CDR(l);
+    }
+
+    if (mv) {
+      p = scheme_current_thread;
+      p->ku.multiple.array = mv;
+      p->ku.multiple.count = mc;
+    }
+  }
+
   scheme_performance_record_end("instantiate", &perf_state);
 
   return (void *)v;
@@ -1912,7 +1942,7 @@ static void show_perf(Performance_Entry *perf_entries, int perf_count,
     }
   }
 
-  if (!depth)
+  if (!depth) {
     fprintf(stderr, ";; %stotal%s  %s%"PRIdPTR " [%s%"PRIdPTR"] ms\n",
             tab_number(total, tab, len),
             tab_string("total", name_tab, name_len),
@@ -1920,6 +1950,12 @@ static void show_perf(Performance_Entry *perf_entries, int perf_count,
             total,
             tab_number(gc_total, gc_tab, gc_len),
             gc_total);
+#ifdef MZ_PRECISE_GC
+    fprintf(stderr, ";; [JIT code: %"PRIdPTR" bytes   JIT code+admin: %"PRIdPTR" bytes]\n",
+            scheme_code_total,
+            scheme_code_page_total);
+#endif
+  }
 }
 
 static void show_all_perf()
diff --git a/racket/src/racket/src/mzmark_type.inc b/racket/src/racket/src/mzmark_type.inc
index 444821bb0e..e619de8b2e 100644
--- a/racket/src/racket/src/mzmark_type.inc
+++ b/racket/src/racket/src/mzmark_type.inc
@@ -160,7 +160,7 @@ static int toplevel_obj_FIXUP(void *p, struct NewGC *gc) {
 
 static int static_toplevel_obj_SIZE(void *p, struct NewGC *gc) {
 #ifndef GC_NO_SIZE_NEEDED_FROM_PROCS
-  gcBYTES_TO_WORDS(sizeof(Scheme_Static_Toplevel));
+  gcBYTES_TO_WORDS(sizeof(Scheme_Toplevel));
 #else
   return 0;
 #endif
@@ -173,7 +173,7 @@ static int static_toplevel_obj_MARK(void *p, struct NewGC *gc) {
   return 0;
 # else
   return
-  gcBYTES_TO_WORDS(sizeof(Scheme_Static_Toplevel));
+  gcBYTES_TO_WORDS(sizeof(Scheme_Toplevel));
 # endif
 #endif
 }
@@ -185,7 +185,7 @@ static int static_toplevel_obj_FIXUP(void *p, struct NewGC *gc) {
   return 0;
 # else
   return
-  gcBYTES_TO_WORDS(sizeof(Scheme_Static_Toplevel));
+  gcBYTES_TO_WORDS(sizeof(Scheme_Toplevel));
 # endif
 #endif
 }
@@ -3507,6 +3507,7 @@ static int linklet_val_MARK(void *p, struct NewGC *gc) {
   gcMARK2(l->bodies, gc);
   gcMARK2(l->constants, gc);
   gcMARK2(l->static_prefix, gc);
+  gcMARK2(l->native_lambdas, gc);
 # ifdef GC_NO_SIZE_NEEDED_FROM_PROCS
   return 0;
 # else
@@ -3528,6 +3529,7 @@ static int linklet_val_FIXUP(void *p, struct NewGC *gc) {
   gcFIXUP2(l->bodies, gc);
   gcFIXUP2(l->constants, gc);
   gcFIXUP2(l->static_prefix, gc);
+  gcFIXUP2(l->native_lambdas, gc);
 # ifdef GC_NO_SIZE_NEEDED_FROM_PROCS
   return 0;
 # else
diff --git a/racket/src/racket/src/mzmarksrc.c b/racket/src/racket/src/mzmarksrc.c
index 1ab8b5ac97..49ee37d241 100644
--- a/racket/src/racket/src/mzmarksrc.c
+++ b/racket/src/racket/src/mzmarksrc.c
@@ -992,6 +992,7 @@ linklet_val {
   gcMARK2(l->bodies, gc);
   gcMARK2(l->constants, gc);
   gcMARK2(l->static_prefix, gc);
+  gcMARK2(l->native_lambdas, gc);
  size:
   gcBYTES_TO_WORDS(sizeof(Scheme_Linklet));
 }
diff --git a/racket/src/racket/src/salloc.c b/racket/src/racket/src/salloc.c
index 6b0a181ffd..ca1b6310a8 100644
--- a/racket/src/racket/src/salloc.c
+++ b/racket/src/racket/src/salloc.c
@@ -943,6 +943,7 @@ START_XFORM_SKIP;
 THREAD_LOCAL_DECL(static void *code_allocation_page_list);
 
 THREAD_LOCAL_DECL(intptr_t scheme_code_page_total);
+THREAD_LOCAL_DECL(intptr_t scheme_code_total);
 
 #if defined(MZ_CODE_ALLOC_USE_MPROTECT) && !defined(MAP_ANON)
 static int fd, fd_created;
@@ -1161,6 +1162,7 @@ void *scheme_malloc_code(intptr_t size)
     sz = (sz + page_size - 1) & ~(page_size - 1);
     pg = malloc_page(sz);
     scheme_code_page_total += sz;
+    scheme_code_total += sz;
     *(intptr_t *)pg = sz;
     chain_page(pg);
     LOG_CODE_MALLOC(1, printf("allocated large %p (%ld) [now %ld]\n", 
@@ -1170,6 +1172,8 @@ void *scheme_malloc_code(intptr_t size)
     bucket = free_list_find_bucket(size);
     size2 = free_list[bucket].size;
 
+    scheme_code_total += size2;
+
     if (!free_list[bucket].elems) {
       /* add a new page's worth of items to the free list */
       int i, count = 0;
@@ -1266,6 +1270,7 @@ void scheme_free_code(void *p)
   if (size >= page_size) {
     /* it was a large object on its own page(s) */
     scheme_code_page_total -= size;
+    scheme_code_total -= size;
     LOG_CODE_MALLOC(1, printf("freeing large %p (%ld) [%ld left]\n", 
                               p, size, scheme_code_page_total));
     unchain_page((char *)p - CODE_HEADER_SIZE);
@@ -1279,6 +1284,7 @@ void scheme_free_code(void *p)
     }
 
     size2 = free_list[bucket].size;
+    scheme_code_total -= size2;
 
     LOG_CODE_MALLOC(0, printf("freeing %ld / %ld\n", size2, bucket));
 
diff --git a/racket/src/racket/src/schpriv.h b/racket/src/racket/src/schpriv.h
index 5be0cba9f7..1e4f819b2c 100644
--- a/racket/src/racket/src/schpriv.h
+++ b/racket/src/racket/src/schpriv.h
@@ -313,6 +313,7 @@ void scheme_init_stack_check(void);
 void scheme_init_overflow(void);
 #ifdef MZ_USE_JIT
 void scheme_init_jit(void);
+void scheme_init_jitprep(void);
 #endif
 #ifdef MZ_PRECISE_GC
 void scheme_register_traversers(void);
@@ -2995,6 +2996,7 @@ void scheme_jit_fill_threadlocal_table();
 
 #ifdef MZ_USE_JIT
 void scheme_on_demand_generate_lambda(Scheme_Native_Closure *nc, int argc, Scheme_Object **argv, int delta);
+void scheme_force_jit_generate(Scheme_Native_Lambda *nlam);
 #endif
 
 struct Start_Module_Args;
@@ -3292,6 +3294,8 @@ struct Scheme_Linklet
   Scheme_Hash_Table *constants; /* holds info about the linklet's body for inlining */
 
   Scheme_Prefix *static_prefix; /* non-NULL for a linklet compiled in static mode */
+
+  Scheme_Object *native_lambdas; /* non-NULL => native lambdas to force-JIT on instantiation */
 };
 
 #define SCHEME_DEFN_VAR_COUNT(d) (SCHEME_VEC_SIZE(d)-1)