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, 60 insertions, 14 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index b2f81b6861..5ff1f794df 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -543,6 +543,8 @@ static Eterm pi_args[] = {
     am_last_calls,
     am_total_heap_size,
     am_suspending,
+    am_min_heap_size,
+    am_min_bin_vheap_size,
 #ifdef HYBRID
     am_message_binary
 #endif
@@ -589,8 +591,10 @@ pi_arg2ix(Eterm arg)
     case am_last_calls:				return 24;
     case am_total_heap_size:			return 25;
     case am_suspending:				return 26;
+    case am_min_heap_size:			return 27;
+    case am_min_bin_vheap_size:			return 28;
 #ifdef HYBRID
-    case am_message_binary:			return 27;
+    case am_message_binary:			return 29;
 #endif
     default:					return -1;
     }
@@ -1355,6 +1359,30 @@ process_info_aux(Process *BIF_P,
 	break;
     }
 
+    case am_fullsweep_after: {
+	Uint hsz = 3;
+	(void) erts_bld_uint(NULL, &hsz, MAX_GEN_GCS(rp));
+	hp = HAlloc(BIF_P, hsz);
+	res = erts_bld_uint(&hp, NULL, MAX_GEN_GCS(rp));
+	break;
+    }
+
+    case am_min_heap_size: {
+	Uint hsz = 3;
+	(void) erts_bld_uint(NULL, &hsz, MIN_HEAP_SIZE(rp));
+	hp = HAlloc(BIF_P, hsz);
+	res = erts_bld_uint(&hp, NULL, MIN_HEAP_SIZE(rp));
+	break;
+    }
+
+    case am_min_bin_vheap_size: {
+	Uint hsz = 3;
+	(void) erts_bld_uint(NULL, &hsz, MIN_VHEAP_SIZE(rp));
+	hp = HAlloc(BIF_P, hsz);
+	res = erts_bld_uint(&hp, NULL, MIN_VHEAP_SIZE(rp));
+	break;
+    }
+
     case am_total_heap_size: {
 	ErlMessage *mp;
 	Uint total_heap_size;
@@ -1433,15 +1461,17 @@ process_info_aux(Process *BIF_P,
         DECL_AM(minor_gcs);
         Eterm t;
 
-	hp = HAlloc(BIF_P, 3+2+3+2+3);
-	t = TUPLE2(hp, AM_minor_gcs, make_small(GEN_GCS(rp)));
-	hp += 3;
-	res = CONS(hp, t, NIL);
-	hp += 2;
-	t = TUPLE2(hp, am_fullsweep_after, make_small(MAX_GEN_GCS(rp)));
-	hp += 3;
-	res = CONS(hp, t, res);
-	hp += 2;
+	hp = HAlloc(BIF_P, 3+2 + 3+2 + 3+2 + 3+2 + 3); /* last "3" is for outside tuple */
+
+	t = TUPLE2(hp, AM_minor_gcs, make_small(GEN_GCS(rp))); hp += 3;
+	res = CONS(hp, t, NIL); hp += 2;
+	t = TUPLE2(hp, am_fullsweep_after, make_small(MAX_GEN_GCS(rp))); hp += 3;
+	res = CONS(hp, t, res); hp += 2;
+
+	t = TUPLE2(hp, am_min_heap_size, make_small(MIN_HEAP_SIZE(rp))); hp += 3;
+	res = CONS(hp, t, res); hp += 2;
+	t = TUPLE2(hp, am_min_bin_vheap_size, make_small(MIN_VHEAP_SIZE(rp))); hp += 3;
+	res = CONS(hp, t, res); hp += 2;
 	break;
     }
 
@@ -1897,16 +1927,32 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(res);
     } else if (BIF_ARG_1 == am_garbage_collection){
 	Uint val = (Uint) erts_smp_atomic_read(&erts_max_gen_gcs);
-	hp = HAlloc(BIF_P, 3+2);
-	res = TUPLE2(hp, am_fullsweep_after, make_small(val));
-	hp += 3;
-	res = CONS(hp, res, NIL);
+	Eterm tup;
+	hp = HAlloc(BIF_P, 3+2 + 3+2 + 3+2);
+
+	tup = TUPLE2(hp, am_fullsweep_after, make_small(val)); hp += 3;
+	res = CONS(hp, tup, NIL); hp += 2;
+
+	tup = TUPLE2(hp, am_min_heap_size, make_small(H_MIN_SIZE)); hp += 3;
+	res = CONS(hp, tup, res); hp += 2;
+
+	tup = TUPLE2(hp, am_min_bin_vheap_size, make_small(BIN_VH_MIN_SIZE)); hp += 3;
+	res = CONS(hp, tup, res); hp += 2;
+
 	BIF_RET(res);
     } else if (BIF_ARG_1 == am_fullsweep_after){
 	Uint val = (Uint) erts_smp_atomic_read(&erts_max_gen_gcs);
 	hp = HAlloc(BIF_P, 3);
 	res = TUPLE2(hp, am_fullsweep_after, make_small(val));
 	BIF_RET(res);
+    } else if (BIF_ARG_1 == am_min_heap_size) {
+	hp = HAlloc(BIF_P, 3);
+	res = TUPLE2(hp, am_min_heap_size,make_small(H_MIN_SIZE));
+	BIF_RET(res);
+    } else if (BIF_ARG_1 == am_min_bin_vheap_size) {
+	hp = HAlloc(BIF_P, 3);
+	res = TUPLE2(hp, am_min_bin_vheap_size,make_small(BIN_VH_MIN_SIZE));
+	BIF_RET(res);
     } else if (BIF_ARG_1 == am_process_count) {
 	BIF_RET(make_small(erts_process_count()));
     } else if (BIF_ARG_1 == am_process_limit) {