make sure to only enable things meant for DATAS when it's on (#90008)

also reverted a couple of things that were supposed to be temporary

src/coreclr/gc/gc.cpp

@@ -2917,6 +2917,7 @@ BOOL gc_heap::should_expand_in_full_gc = FALSE;
 #endif //!USE_REGIONS
 
 #ifdef DYNAMIC_HEAP_COUNT
+int gc_heap::dynamic_adaptation_mode = dynamic_adaptation_default;
 gc_heap::dynamic_heap_count_data_t SVR::gc_heap::dynamic_heap_count_data;
 #endif // DYNAMIC_HEAP_COUNT
 
@@ -14032,6 +14033,26 @@ HRESULT gc_heap::initialize_gc (size_t soh_segment_size,
 
     HRESULT hres = S_OK;
 
+    conserve_mem_setting = (int)GCConfig::GetGCConserveMem();
+
+#ifdef DYNAMIC_HEAP_COUNT
+    dynamic_adaptation_mode = (int)GCConfig::GetGCDynamicAdaptationMode();
+    if (GCConfig::GetHeapCount() != 0)
+    {
+        dynamic_adaptation_mode = 0;
+    }
+
+    if ((dynamic_adaptation_mode == dynamic_adaptation_to_application_sizes) && (conserve_mem_setting == 0))
+        conserve_mem_setting = 5;
+#endif //DYNAMIC_HEAP_COUNT
+
+    if (conserve_mem_setting < 0)
+        conserve_mem_setting = 0;
+    if (conserve_mem_setting > 9)
+        conserve_mem_setting = 9;
+
+    dprintf (1, ("conserve_mem_setting = %d", conserve_mem_setting));
+
 #ifdef WRITE_WATCH
     hardware_write_watch_api_supported();
 #ifdef BACKGROUND_GC
@@ -14271,7 +14292,7 @@ gc_heap::init_semi_shared()
 #ifdef MULTIPLE_HEAPS
     mark_list_size = min (100*1024, max (8192, soh_segment_size/(2*10*32)));
 #ifdef DYNAMIC_HEAP_COUNT
-    if (GCConfig::GetGCDynamicAdaptationMode() == 1 && GCConfig::GetHeapCount() == 0)
+    if (dynamic_adaptation_mode == dynamic_adaptation_to_application_sizes)
     {
         // we'll actually start with one heap in this case
         g_mark_list_total_size = mark_list_size;
@@ -14480,16 +14501,6 @@ gc_heap::init_semi_shared()
 #endif //FEATURE_LOH_COMPACTION
 #endif //FEATURE_EVENT_TRACE
 
-    conserve_mem_setting  = (int)GCConfig::GetGCConserveMem();
-    if (conserve_mem_setting == 0 && GCConfig::GetGCDynamicAdaptationMode() == 1)
-        conserve_mem_setting = 5;
-    if (conserve_mem_setting < 0)
-        conserve_mem_setting = 0;
-    if (conserve_mem_setting > 9)
-        conserve_mem_setting = 9;
-
-    dprintf (1, ("conserve_mem_setting = %d", conserve_mem_setting));
-
     reset_mm_p = TRUE;
 
     ret = 1;
@@ -21229,7 +21240,7 @@ int gc_heap::generation_to_condemn (int n_initial,
     int n_alloc = n;
     if (heap_number == 0)
     {
-        dprintf (5555, ("init: %d(%d)", n_initial, settings.reason));
+        dprintf (GTC_LOG, ("init: %d(%d)", n_initial, settings.reason));
     }
     int i = 0;
     int temp_gen = 0;
@@ -22570,10 +22581,6 @@ void gc_heap::gc1()
             gc_t_join.restart();
         }
 
-#ifdef USE_REGIONS
-//        rethread_fl_items ();
-#endif //USE_REGIONS
-
         update_end_gc_time_per_heap();
         add_to_history_per_heap();
         alloc_context_count = 0;
@@ -25033,15 +25040,8 @@ void gc_heap::check_heap_count ()
 {
     dynamic_heap_count_data.new_n_heaps = n_heaps;
 
-    if (GCConfig::GetHeapCount() != 0)
-    {
-        // don't change the heap count if we see an environment variable setting it explicitly
-        return;
-    }
-
-    if (GCConfig::GetGCDynamicAdaptationMode() == 0)
+    if (dynamic_adaptation_mode != dynamic_adaptation_to_application_sizes)
     {
-        // don't change the heap count dynamically if the feature isn't explicitly enabled
         return;
     }
 
@@ -43053,7 +43053,8 @@ size_t gc_heap::desired_new_allocation (dynamic_data* dd,
                                           max (min_gc_size, (max_size/3)));
                 }
 
-                if (conserve_mem_setting != 0)
+#ifdef DYNAMIC_HEAP_COUNT
+                if (dynamic_adaptation_mode == dynamic_adaptation_to_application_sizes)
                 {
                     // if this is set, limit gen 0 size to a small multiple of the older generations
                     float f_older_gen = ((10.0f / conserve_mem_setting) - 1) * 0.5f;
@@ -43079,6 +43080,7 @@ size_t gc_heap::desired_new_allocation (dynamic_data* dd,
                         older_size,
                         new_allocation));
                 }
+#endif //DYNAMIC_HEAP_COUNT
             }
         }
 
@@ -48281,9 +48283,9 @@ HRESULT GCHeap::Initialize()
     {
 #ifdef DYNAMIC_HEAP_COUNT
         // if no heap count was specified, and we are told to adjust heap count dynamically ...
-        if (GCConfig::GetHeapCount() == 0 && GCConfig::GetGCDynamicAdaptationMode() == 1)
+        if (gc_heap::dynamic_adaptation_mode == dynamic_adaptation_to_application_sizes)
         {
-            // ... start with only 1 heap
+            // start with only 1 heap
             gc_heap::smoothed_desired_total[0] /= gc_heap::n_heaps;
             gc_heap::g_heaps[0]->change_heap_count (1);
         }
@@ -50746,11 +50748,13 @@ size_t gc_heap::get_gen0_min_size()
         int n_heaps = 1;
 #endif //SERVER_GC
 
-        if (GCConfig::GetGCConserveMem() != 0 || GCConfig::GetGCDynamicAdaptationMode() == 1)
+#ifdef DYNAMIC_HEAP_COUNT
+        if (dynamic_adaptation_mode == dynamic_adaptation_to_application_sizes)
         {
             // if we are asked to be stingy with memory, limit gen 0 size
             gen0size = min (gen0size, (4*1024*1024));
         }
+#endif //DYNAMIC_HEAP_COUNT
 
         dprintf (1, ("gen0size: %zd * %d = %zd, physical mem: %zd / 6 = %zd",
                 gen0size, n_heaps, (gen0size * n_heaps),

src/coreclr/gc/gcpriv.h

@@ -617,6 +617,14 @@ enum gc_type
     gc_type_max = 3
 };
 
+#ifdef DYNAMIC_HEAP_COUNT
+enum gc_dynamic_adaptation_mode
+{
+    dynamic_adaptation_default = 0,
+    dynamic_adaptation_to_application_sizes = 1,
+};
+#endif //DYNAMIC_HEAP_COUNT
+
 //encapsulates the mechanism for the current gc
 class gc_mechanisms
 {
@@ -4427,6 +4435,10 @@ private:
     PER_HEAP_ISOLATED_FIELD_INIT_ONLY size_t youngest_gen_desired_th;
 #endif //HOST_64BIT
 
+#ifdef DYNAMIC_HEAP_COUNT
+    PER_HEAP_ISOLATED_FIELD_INIT_ONLY int dynamic_adaptation_mode;
+#endif //DYNAMIC_HEAP_COUNT
+
     /********************************************/
     // PER_HEAP_ISOLATED_FIELD_DIAG_ONLY fields //
     /********************************************/