Hi, I used valgrind to check the memory usage of my OCaml byte code, but I found that a memory leak. I'm very confused what the problem is. I tried a very simple code as following, and compileed it. +++++++++++++++++++++++ let test = let a = 1 in let b = a + 5 in printf "%d\n" b; ;; test;; +++++++++++++++++++++++ And I run valgrind to check: valgrind --leak-check=yes ./obj/x86_LINUX/test5.byte.exe I got the following report: ==21692== Memcheck, a memory error detector ==21692== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al. ==21692== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info ==21692== Command: ./obj/x86_LINUX/test5.byte.exe ==21692== 6 ==21692== ==21692== HEAP SUMMARY: ==21692== in use at exit: 430,488 bytes in 20 blocks ==21692== total heap usage: 68 allocs, 48 frees, 446,837 bytes allocated ==21692== ==21692== 120 bytes in 1 blocks are definitely lost in loss record 9 of 17 ==21692== at 0x4A05E1C: malloc (vg_replace_malloc.c:195) ==21692== by 0x9AA510: caml_init_major_heap (in /home/kecheng/symbolic_simulation/cvc_test/cvc_1.5/obj/x86_LINUX/test5.byte.exe) ==21692== by 0x9A2A1A: caml_init_gc (in /home/kecheng/symbolic_simulation/cvc_test/cvc_1.5/obj/x86_LINUX/test5.byte.exe) ==21692== by 0x997E9D: caml_main (in /home/kecheng/symbolic_simulation/cvc_test/cvc_1.5/obj/x86_LINUX/test5.byte.exe) ==21692== by 0x9981CB: main (in /home/kecheng/symbolic_simulation/cvc_test/cvc_1.5/obj/x86_LINUX/test5.byte.exe) ==21692== ==21692== LEAK SUMMARY: ==21692== definitely lost: 120 bytes in 1 blocks ==21692== indirectly lost: 0 bytes in 0 blocks ==21692== possibly lost: 0 bytes in 0 blocks ==21692== still reachable: 430,368 bytes in 19 blocks ==21692== suppressed: 0 bytes in 0 blocks ==21692== Reachable blocks (those to which a pointer was found) are not shown. ==21692== To see them, rerun with: --leak-check=full --show-reachable=yes ==21692== ==21692== For counts of detected and suppressed errors, rerun with: -v ==21692== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 4 from 4) Kecheng 2010-11-23