Merge pull request #9670 from lpw25/stat-full-major-collections

Report full major collections in Gc stats

Changes

@@ -62,6 +62,9 @@ Working version
   (Xavier Leroy, review by Jacques-Henri Jourdan, Damien Doligez, and
   Stephen Dolan)
 
+- #9670: Report full major collections in Gc stats.
+  (Leo White, review by Gabriel Scherer)
+
 - #9675: Remove the caml_static_{alloc,free,resize} primitives, now unused.
   (Xavier Leroy, review by Gabriel Scherer)
 

runtime/caml/domain_state.tbl

@@ -71,6 +71,7 @@ DOMAIN_STATE(intnat, stat_major_collections)
 DOMAIN_STATE(intnat, stat_heap_wsz)
 DOMAIN_STATE(intnat, stat_top_heap_wsz)
 DOMAIN_STATE(intnat, stat_compactions)
+DOMAIN_STATE(intnat, stat_forced_major_collections)
 DOMAIN_STATE(intnat, stat_heap_chunks)
 /* See gc_ctrl.c */
 

runtime/compact.c

@@ -562,6 +562,7 @@ void caml_compact_heap_maybe (void)
     caml_gc_message (0x200, "Automatic compaction triggered.\n");
     caml_empty_minor_heap ();  /* minor heap must be empty for compaction */
     caml_finish_major_cycle ();
+    ++ Caml_state->stat_forced_major_collections;
 
     fw = caml_fl_cur_wsz;
     fp = 100.0 * fw / (Caml_state->stat_heap_wsz - fw);

runtime/domain.c

@@ -69,6 +69,7 @@ void caml_init_domain ()
   Caml_state->stat_heap_wsz = 0;
   Caml_state->stat_top_heap_wsz = 0;
   Caml_state->stat_compactions = 0;
+  Caml_state->stat_forced_major_collections = 0;
   Caml_state->stat_heap_chunks = 0;
 
   Caml_state->backtrace_active = 0;

runtime/gc_ctrl.c

@@ -233,9 +233,10 @@ static value heap_stats (int returnstats)
     intnat majcoll = Caml_state->stat_major_collections;
     intnat heap_words = Caml_state->stat_heap_wsz;
     intnat cpct = Caml_state->stat_compactions;
+    intnat forcmajcoll = Caml_state->stat_forced_major_collections;
     intnat top_heap_words = Caml_state->stat_top_heap_wsz;
 
-    res = caml_alloc_tuple (16);
+    res = caml_alloc_tuple (17);
     Store_field (res, 0, caml_copy_double (minwords));
     Store_field (res, 1, caml_copy_double (prowords));
     Store_field (res, 2, caml_copy_double (majwords));
@@ -252,6 +253,7 @@ static value heap_stats (int returnstats)
     Store_field (res, 13, Val_long (cpct));
     Store_field (res, 14, Val_long (top_heap_words));
     Store_field (res, 15, Val_long (caml_stack_usage()));
+    Store_field (res, 16, Val_long (forcmajcoll));
     CAMLreturn (res);
   }else{
     CAMLreturn (Val_unit);
@@ -292,9 +294,10 @@ CAMLprim value caml_gc_quick_stat(value v)
   intnat heap_words = Caml_state->stat_heap_wsz;
   intnat top_heap_words = Caml_state->stat_top_heap_wsz;
   intnat cpct = Caml_state->stat_compactions;
+  intnat forcmajcoll = Caml_state->stat_forced_major_collections;
   intnat heap_chunks = Caml_state->stat_heap_chunks;
 
-  res = caml_alloc_tuple (16);
+  res = caml_alloc_tuple (17);
   Store_field (res, 0, caml_copy_double (minwords));
   Store_field (res, 1, caml_copy_double (prowords));
   Store_field (res, 2, caml_copy_double (majwords));
@@ -311,6 +314,7 @@ CAMLprim value caml_gc_quick_stat(value v)
   Store_field (res, 13, Val_long (cpct));
   Store_field (res, 14, Val_long (top_heap_words));
   Store_field (res, 15, Val_long (caml_stack_usage()));
+  Store_field (res, 16, Val_long (forcmajcoll));
   CAMLreturn (res);
 }
 
@@ -504,6 +508,7 @@ CAMLprim value caml_gc_set(value v)
     caml_empty_minor_heap ();
     caml_finish_major_cycle ();
     caml_finish_major_cycle ();
+    ++ Caml_state->stat_forced_major_collections;
     caml_compact_heap (newpolicy);
     caml_gc_message (0x20, "New allocation policy: %"
                      ARCH_INTNAT_PRINTF_FORMAT "u\n", newpolicy);
@@ -583,6 +588,7 @@ CAMLprim value caml_gc_full_major(value v)
   if (Is_exception_result(exn)) goto cleanup;
   caml_empty_minor_heap ();
   caml_finish_major_cycle ();
+  ++ Caml_state->stat_forced_major_collections;
   test_and_compact ();
   // call finalisers
   exn = caml_process_pending_actions_exn();
@@ -617,6 +623,7 @@ CAMLprim value caml_gc_compaction(value v)
   if (Is_exception_result(exn)) goto cleanup;
   caml_empty_minor_heap ();
   caml_finish_major_cycle ();
+  ++ Caml_state->stat_forced_major_collections;
   caml_compact_heap (-1);
   // call finalisers
   exn = caml_process_pending_actions_exn();

runtime/sys.c

@@ -130,6 +130,7 @@ CAMLprim value caml_sys_exit(value retcode_v)
     intnat heap_chunks = Caml_state->stat_heap_chunks;
     intnat top_heap_words = Caml_state->stat_top_heap_wsz;
     intnat cpct = Caml_state->stat_compactions;
+    intnat forcmajcoll = Caml_state->stat_forced_major_collections;
     caml_gc_message(0x400, "allocated_words: %.0f\n", allocated_words);
     caml_gc_message(0x400, "minor_words: %.0f\n", minwords);
     caml_gc_message(0x400, "promoted_words: %.0f\n", prowords);
@@ -146,6 +147,9 @@ CAMLprim value caml_sys_exit(value retcode_v)
                     top_heap_words);
     caml_gc_message(0x400, "compactions: %"ARCH_INTNAT_PRINTF_FORMAT"d\n",
                     cpct);
+    caml_gc_message(0x400,
+                    "forced_major_collections: %"ARCH_INTNAT_PRINTF_FORMAT"d\n",
+                    forcmajcoll);
   }
 
 #ifndef NATIVE_CODE

stdlib/gc.ml

@@ -31,6 +31,7 @@ type stat = {
   compactions : int;
   top_heap_words : int;
   stack_size : int;
+  forced_major_collections: int;
 }
 
 type control = {
@@ -70,9 +71,10 @@ open Printf
 
 let print_stat c =
   let st = stat () in
-  fprintf c "minor_collections: %d\n" st.minor_collections;
-  fprintf c "major_collections: %d\n" st.major_collections;
-  fprintf c "compactions:       %d\n" st.compactions;
+  fprintf c "minor_collections:      %d\n" st.minor_collections;
+  fprintf c "major_collections:      %d\n" st.major_collections;
+  fprintf c "compactions:            %d\n" st.compactions;
+  fprintf c "forced_major_collections: %d\n" st.forced_major_collections;
   fprintf c "\n";
   let l1 = String.length (sprintf "%.0f" st.minor_words) in
   fprintf c "minor_words:    %*.0f\n" l1 st.minor_words;

stdlib/gc.mli

@@ -72,6 +72,10 @@ type stat =
 
     stack_size: int;
     (** Current size of the stack, in words. @since 3.12.0 *)
+
+    forced_major_collections: int;
+    (** Number of forced full major collections completed since the program
+        was started. @since 4.12.0 *)
 }
 (** The memory management counters are returned in a [stat] record.