diff --git a/collects/scribblings/inside/memory.scrbl b/collects/scribblings/inside/memory.scrbl
index 09a571d380..2e5b672c93 100644
--- a/collects/scribblings/inside/memory.scrbl
+++ b/collects/scribblings/inside/memory.scrbl
@@ -56,12 +56,15 @@ The basic collector allocation functions are:
  object for future garbage collection (as described
  in @secref["im:3m"]).}
 
- @item{@cppi{scheme_malloc_allow_interior} --- Allocates a large
- array of pointers such that references are allowed into the middle of
- the block under 3m, and such pointers prevent the block from being
- collected. This procedure is the same as @cppi{scheme_malloc} with
- the conservative collector, but in the that case, having @italic{only}
- a pointer into the interior will not prevent the array from being
+ @item{@cppi{scheme_malloc_allow_interior} --- Allocates an array of
+ pointers such that the array is never moved by the garbage collector
+ and references are allowed into the middle of the block under 3m (and
+ pointers to the middle prevent the block from being collected). Use
+ this procedure sparingly, because small, non-moving objects are
+ handled less efficiently than movable objects by the 3m collector.
+ This procedure is the same as @cppi{scheme_malloc} with the
+ conservative collector, but in the that case, having @italic{only} a
+ pointer into the interior will not prevent the array from being
  collected.}
 
  @item{@cppi{scheme_malloc_atomic_allow_interior} --- Like
@@ -651,13 +654,13 @@ Like @cpp{scheme_malloc}, but in 3m, the type tag determines how the
 @function[(void* scheme_malloc_allow_interior
            [size_t n])]{
 
-Like @cpp{scheme_malloc}, but in 3m, pointers are allowed to
+Like @cpp{scheme_malloc}, but in 3m, the object never moves, and pointers are allowed to
  reference the middle of the object; see @secref["im:memoryalloc"].}
 
 @function[(void* scheme_malloc_atomic_allow_interior
            [size_t n])]{
 
-Like @cpp{scheme_malloc_atomic}, but in 3m, pointers are allowed to
+Like @cpp{scheme_malloc_atomic}, but in 3m, the object never moves, and pointers are allowed to
  reference the middle of the object; see @secref["im:memoryalloc"].}
 
 @function[(char* scheme_strdup
diff --git a/collects/tests/plot/contour-out.png b/collects/tests/plot/contour-out.png
deleted file mode 100644
index c1d2dc736b..0000000000
Binary files a/collects/tests/plot/contour-out.png and /dev/null differ
diff --git a/src/racket/gc2/newgc.c b/src/racket/gc2/newgc.c
index 13e79149b8..9808bddb86 100644
--- a/src/racket/gc2/newgc.c
+++ b/src/racket/gc2/newgc.c
@@ -1251,7 +1251,7 @@ void *GC_malloc_array_tagged(size_t s)            { return allocate(s, PAGE_TARR
 void *GC_malloc_atomic(size_t s)                  { return allocate(s, PAGE_ATOMIC); }
 void *GC_malloc_atomic_uncollectable(size_t s)    { return ofm_malloc_zero(s); }
 void *GC_malloc_allow_interior(size_t s)          { return allocate_medium(s, PAGE_ARRAY); }
-void *GC_malloc_atomic_allow_interior(size_t s)   { return allocate_big(s, PAGE_ATOMIC); }
+void *GC_malloc_atomic_allow_interior(size_t s)   { return allocate_medium(s, PAGE_ATOMIC); }
 void *GC_malloc_tagged_allow_interior(size_t s)   { return allocate_medium(s, PAGE_TAGGED); }
 void *GC_malloc_one_small_dirty_tagged(size_t s)  { return fast_malloc_one_small_tagged(s, 1); }
 void *GC_malloc_one_small_tagged(size_t s)        { return fast_malloc_one_small_tagged(s, 0); }