Improve binary garbage collection

The garbage collector in r13b03 is too aggressive in some cases. This
commit raises the level of default initial allowed binary garbage
(virtual heap for binaries) before collecting from 233 words to
46368 words (181 kB on 32-bit).

A new option, min_bin_vheap_size, has been added to spawn_opt,
system_flag and process_flag can be used to change the default values.

The option can also be used with system_info and process_info to
inspect the values.

For symmetry the option min_heap_size has been added to the above
functions where it was previously missing.

Add testcases for min_bin_vheap_size and min_heap_size for
functions process_flag/2, process_info/2, system_info/2 and
spawn_opt/2.

1 files changed, 4 insertions, 2 deletions

diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 1f841b2113..f58b6932b3 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -477,6 +477,7 @@ struct ErtsPendingSuspend_ {
 #  define MSO(p)            (p)->off_heap
 #  define MIN_HEAP_SIZE(p)  (p)->min_heap_size
 
+#  define MIN_VHEAP_SIZE(p)   (p)->min_vheap_size
 #  define BIN_VHEAP_SZ(p)     (p)->bin_vheap_sz
 #  define BIN_OLD_VHEAP_SZ(p) (p)->bin_old_vheap_sz
 #  define BIN_OLD_VHEAP(p)    (p)->bin_old_vheap
@@ -495,6 +496,7 @@ struct process {
     Eterm* hend;		/* Heap end */
     Uint heap_sz;		/* Size of heap in words */
     Uint min_heap_size;         /* Minimum size of heap (in words). */
+    Uint min_vheap_size;        /* Minimum size of virtual heap (in words). */
 
 #if !defined(NO_FPE_SIGNALS)
     volatile unsigned long fp_exception;
@@ -730,8 +732,8 @@ typedef struct {
      * The following items are only initialized if the SPO_USE_ARGS flag is set.
      */
     Uint min_heap_size;		/* Minimum heap size (must be a valued returned
-				 * from next_heap_size()).
-				 */
+				 * from next_heap_size()).  */
+    Uint min_vheap_size;	/* Minimum virtual heap size  */
     int priority;		/* Priority for process. */
     Uint16 max_gen_gcs;		/* Maximum number of gen GCs before fullsweep. */
     int scheduler;