Document left mrbconfs.

doc/mrbconf/README.md

@@ -86,6 +86,10 @@ will be defined as `mrb_int`.
 * Ignored when `MRB_GC_FIXED_ARENA` isn't defined.
 * Defines fixed GC arena size.
 
+`MRB_HEAP_PAGE_SIZE`
+* Defines value is `1024`.
+* Specifies number of `RBasic` per each heap page.
+
 ## Memory pool configuration.
 
 `POOL_ALIGNMENT`
@@ -123,3 +127,34 @@ largest value of required alignment.
 `MRB_WORD_BOXING`
 * If defined represent `mrb_value` as a word.
 * If defined `Float` will be a mruby object with `RBasic`.
+
+## Instance variable configuration.
+`MRB_USE_IV_SEGLIST`
+* If defined enable segmented list in instance variable table instead of khash.
+* Segmented list is a linked list of key and value segments.
+* It will linear search instead of hash search.
+
+`MRB_SEGMENT_SIZE`
+* Default value is `4`.
+* Specifies size of each segment in segment list.
+* Ignored when `MRB_USE_IV_SEGLIST` isn't defined.
+
+`MRB_IVHASH_INIT_SIZE`
+* Default value is `8`.
+* Specifies initial size for instance variable table.
+* Ignored when `MRB_USE_IV_SEGLIST` is defined.
+
+## Other configuration.
+`MRB_FUNCALL_ARGC_MAX`
+* Default value is `16`.
+* Specifies 4th argument(`argc`) max value of `mrb_funcall`.
+* Raises `ArgumentError` when the `argc` argument is bigger then this value `mrb_funcall`.
+
+`KHASH_DEFAULT_SIZE`
+* Default value is `32`.
+* Specifies default size of khash table bucket.
+* Used in `kh_init_ ## name` function.
+
+`MRB_STR_BUF_MIN_SIZE`
+* Default value is `128`.
+* Specifies initial capacity of `RString` created by `mrb_str_buf_new` function..