$ poly -v
Poly/ML 5.9.2 Release    RTS version: X86_64-5.9.2

$ cat code.sml
(* This allocates ~80MB of live data that cannot be GC'd *)
fun make_list 0 acc = acc
  | make_list n acc = make_list (n-1) ((n, Array.array(10000, n)) :: acc)
val _ = print "Allocating 1000 arrays of 10000 ints each (~80MB)...\n"
val big = make_list 1000 [];
val _ = print ("Success: Created " ^ Int.toString (length big) ^ " arrays\n");
val _ = OS.Process.exit OS.Process.success;

$ poly <code.sml
Poly/ML 5.9.2 Release
Allocating 1000 arrays of 10000 ints each (~80MB)...
val big =
   [(1, fromList[1, 1, 1, 1, 1, 1, 1, 1, 1, ...]),
    (2, fromList[2, 2, 2, 2, 2, 2, 2, 2, ...]),
    (3, fromList[3, 3, 3, 3, 3, 3, 3, ...]),
    (4, fromList[4, 4, 4, 4, 4, 4, ...]), (5, fromList[5, 5, 5, 5, 5, ...]),
    (6, fromList[6, 6, 6, 6, ...]), (7, fromList[7, 7, 7, ...]),
    (8, fromList[8, 8, ...]), (9, fromList[9, ...]), (10, fromList[...]),
    ...]: (int * int array) list
val make_list = fn: int -> (int * int array) list -> (int * int array) list
Success: Created 1000 arrays

$ poly --maxheap=2 <code.sml
Poly/ML 5.9.2 Release
Run out of store - interrupting threads
Run out of store - interrupting threads
Run out of store - interrupting threads
Run out of store - interrupting threads
Run out of store - interrupting threads
[...truncated...]

$ poly --maxheap=1 <code.sml
Poly/ML 5.9.2 Release
Allocating 1000 arrays of 10000 ints each (~80MB)...
val big =
   [(1, fromList[1, 1, 1, 1, 1, 1, 1, 1, 1, ...]),
    (2, fromList[2, 2, 2, 2, 2, 2, 2, 2, ...]),
    (3, fromList[3, 3, 3, 3, 3, 3, 3, ...]),
    (4, fromList[4, 4, 4, 4, 4, 4, ...]), (5, fromList[5, 5, 5, 5, 5, ...]),
    (6, fromList[6, 6, 6, 6, ...]), (7, fromList[7, 7, 7, ...]),
    (8, fromList[8, 8, ...]), (9, fromList[9, ...]), (10, fromList[...]),
    ...]: (int * int array) list
val make_list = fn: int -> (int * int array) list -> (int * int array) list
Success: Created 1000 arrays