Change the default policy to best-fit and space overhead to 100

Author: lpw25

runtime/caml/config.h

@@ -220,7 +220,7 @@ typedef uint64_t uintnat;
 /* Default speed setting for the major GC.  The heap will grow until
    the dead objects and the free list represent this percentage of the
    total size of live objects. */
-#define Percent_free_def 80
+#define Percent_free_def 100
 
 /* Default setting for the compacter: 500%
    (i.e. trigger the compacter when 5/6 of the heap is free or garbage)

runtime/freelist.c

@@ -1780,20 +1780,20 @@ typedef enum caml_policy_t {
   policy_best_fit = 2,
 } caml_policy_t;
 
-uintnat caml_allocation_policy = policy_next_fit;
+uintnat caml_allocation_policy = policy_best_fit;
 
 /* These pointers are changed when switching between allocation
    policies. */
-static header_t *(*p_allocate) (mlsize_t wo_sz) = &nf_allocate;
-static void (*p_init_merge) (void) = &nf_init_merge;
-static void (*p_reset) (void) = &nf_reset;
-static header_t *(*p_merge_block) (value bp, char *limit) = &nf_merge_block;
-static void (*p_add_blocks) (value bp) = &nf_add_blocks;
+static header_t *(*p_allocate) (mlsize_t wo_sz) = &bf_allocate;
+static void (*p_init_merge) (void) = &bf_init_merge;
+static void (*p_reset) (void) = &bf_reset;
+static header_t *(*p_merge_block) (value bp, char *limit) = &bf_merge_block;
+static void (*p_add_blocks) (value bp) = &bf_add_blocks;
 static void (*p_make_free_blocks)
   (value *p, mlsize_t size, int do_merge, int color)
-  = &nf_make_free_blocks;
+  = &bf_make_free_blocks;
 #ifdef DEBUG
-static void (*p_check) (void) = &nf_check;
+static void (*p_check) (void) = &bf_check;
 #endif
 
 /********************* exported functions *****************************/