Minor: Split heap recorder stats into young/non-young

This avoids "muddying" the waters for our stats, as young object updates will have more objects skipped, and different mixes of alive/dead.
DataDog · Oct 23, 2024 · dd653ce · dd653ce
1 parent 6494eee
commit dd653ce
Showing 1 changed file with 17 additions and 6 deletions.
diff --git a/ext/datadog_profiling_native_extension/heap_recorder.c b/ext/datadog_profiling_native_extension/heap_recorder.c
@@ -190,6 +190,10 @@ struct heap_recorder {
     unsigned long updates_skipped_gcgen;
     unsigned long updates_skipped_time;
 
+    double ewma_young_objects_alive;
+    double ewma_young_objects_dead;
+    double ewma_young_objects_skipped; // Note: Here "young" refers to the young update; objects skipped includes non-young objects
+
     double ewma_objects_alive;
     double ewma_objects_dead;
     double ewma_objects_skipped;
@@ -491,12 +495,15 @@ static void heap_recorder_update(heap_recorder *heap_recorder, bool full_update)
   heap_recorder->stats_lifetime.updates_successful++;
 
   // Lifetime stats updating
-  // TODO: Discuss with Alex -- should we separate these out between young objects only and full updates?
-  // Tracking them together in this way seems to be muddying the waters -- young object updates will have more objects
-  // skipped, and different mixes of alive/dead
-  heap_recorder->stats_lifetime.ewma_objects_alive = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_alive, heap_recorder->stats_last_update.objects_alive);
-  heap_recorder->stats_lifetime.ewma_objects_dead = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_dead, heap_recorder->stats_last_update.objects_dead);
-  heap_recorder->stats_lifetime.ewma_objects_skipped = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_skipped, heap_recorder->stats_last_update.objects_skipped);
+  if (!full_update) {
+    heap_recorder->stats_lifetime.ewma_young_objects_alive = ewma_stat(heap_recorder->stats_lifetime.ewma_young_objects_alive, heap_recorder->stats_last_update.objects_alive);
+    heap_recorder->stats_lifetime.ewma_young_objects_dead = ewma_stat(heap_recorder->stats_lifetime.ewma_young_objects_dead, heap_recorder->stats_last_update.objects_dead);
+    heap_recorder->stats_lifetime.ewma_young_objects_skipped = ewma_stat(heap_recorder->stats_lifetime.ewma_young_objects_skipped, heap_recorder->stats_last_update.objects_skipped);
+  } else {
+    heap_recorder->stats_lifetime.ewma_objects_alive = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_alive, heap_recorder->stats_last_update.objects_alive);
+    heap_recorder->stats_lifetime.ewma_objects_dead = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_dead, heap_recorder->stats_last_update.objects_dead);
+    heap_recorder->stats_lifetime.ewma_objects_skipped = ewma_stat(heap_recorder->stats_lifetime.ewma_objects_skipped, heap_recorder->stats_last_update.objects_skipped);
+  }
 
   heap_recorder->updating = false;
 }
@@ -582,6 +589,10 @@ VALUE heap_recorder_state_snapshot(heap_recorder *heap_recorder) {
     ID2SYM(rb_intern("lifetime_updates_skipped_concurrent")), /* => */ LONG2NUM(heap_recorder->stats_lifetime.updates_skipped_concurrent),
     ID2SYM(rb_intern("lifetime_updates_skipped_gcgen")), /* => */ LONG2NUM(heap_recorder->stats_lifetime.updates_skipped_gcgen),
     ID2SYM(rb_intern("lifetime_updates_skipped_time")), /* => */ LONG2NUM(heap_recorder->stats_lifetime.updates_skipped_time),
+    ID2SYM(rb_intern("lifetime_ewma_young_objects_alive")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_young_objects_alive),
+    ID2SYM(rb_intern("lifetime_ewma_young_objects_dead")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_young_objects_dead),
+      // Note: Here "young" refers to the young update; objects skipped includes non-young objects
+    ID2SYM(rb_intern("lifetime_ewma_young_objects_skipped")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_young_objects_skipped),
     ID2SYM(rb_intern("lifetime_ewma_objects_alive")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_objects_alive),
     ID2SYM(rb_intern("lifetime_ewma_objects_dead")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_objects_dead),
     ID2SYM(rb_intern("lifetime_ewma_objects_skipped")), /* => */ DBL2NUM(heap_recorder->stats_lifetime.ewma_objects_skipped),