Bug 1164982 - Record telemetry for GC max pause during animations; r=sfink

--HG--
extra : rebase_source : 1a774dca8b27f9280dc41676c58307e74eb47441

js/public/SliceBudget.h

@@ -70,9 +70,9 @@ struct JS_PUBLIC_API(SliceBudget)
         return checkOverBudget();
     }
 
-    bool isUnlimited() const {
-        return deadline == unlimitedDeadline;
-    }
+    bool isWorkBudget() const { return deadline == 0; }
+    bool isTimeBudget() const { return deadline > 0 && !isUnlimited(); }
+    bool isUnlimited() const { return deadline == unlimitedDeadline; }
 
     int describe(char* buffer, size_t maxlen) const;
 

js/src/gc/GCRuntime.h

@@ -771,28 +771,30 @@ class GCRuntime
     JS::Zone* getCurrentZoneGroup() { return currentZoneGroup; }
     void setFoundBlackGrayEdges() { foundBlackGrayEdges = true; }
 
-    uint64_t gcNumber() { return number; }
+    uint64_t gcNumber() const { return number; }
     void incGcNumber() { ++number; }
 
-    uint64_t minorGCCount() { return minorGCNumber; }
+    uint64_t minorGCCount() const { return minorGCNumber; }
     void incMinorGcNumber() { ++minorGCNumber; }
 
-    uint64_t majorGCCount() { return majorGCNumber; }
+    uint64_t majorGCCount() const { return majorGCNumber; }
     void incMajorGcNumber() { ++majorGCNumber; }
 
-    bool isIncrementalGc() { return isIncremental; }
-    bool isFullGc() { return isFull; }
+    int64_t defaultSliceBudget() const { return sliceBudget; }
+
+    bool isIncrementalGc() const { return isIncremental; }
+    bool isFullGc() const { return isFull; }
 
     bool shouldCleanUpEverything() { return cleanUpEverything; }
 
-    bool areGrayBitsValid() { return grayBitsValid; }
+    bool areGrayBitsValid() const { return grayBitsValid; }
     void setGrayBitsInvalid() { grayBitsValid = false; }
 
     bool minorGCRequested() const { return minorGCTriggerReason != JS::gcreason::NO_REASON; }
     bool majorGCRequested() const { return majorGCTriggerReason != JS::gcreason::NO_REASON; }
     bool isGcNeeded() { return minorGCRequested() || majorGCRequested(); }
 
-    bool fullGCForAtomsRequested() { return fullGCForAtomsRequested_; }
+    bool fullGCForAtomsRequested() const { return fullGCForAtomsRequested_; }
 
     double computeHeapGrowthFactor(size_t lastBytes);
     size_t computeTriggerBytes(double growthFactor, size_t lastBytes);
@@ -1161,7 +1163,7 @@ class GCRuntime
      */
     bool interFrameGC;
 
-    /* Default budget for incremental GC slice. See SliceBudget in jsgc.h. */
+    /* Default budget for incremental GC slice. See js/SliceBudget.h. */
     int64_t sliceBudget;
 
     /*

js/src/gc/Statistics.cpp

@@ -954,8 +954,16 @@ Statistics::endSlice()
         slices.back().end = PRMJ_Now();
         slices.back().endFaults = GetPageFaultCount();
 
-        runtime->addTelemetry(JS_TELEMETRY_GC_SLICE_MS, t(slices.back().end - slices.back().start));
+        int64_t sliceTime = slices.back().end - slices.back().start;
+        runtime->addTelemetry(JS_TELEMETRY_GC_SLICE_MS, t(sliceTime));
         runtime->addTelemetry(JS_TELEMETRY_GC_RESET, !!slices.back().resetReason);
+
+        if (slices.back().budget.isTimeBudget()) {
+            int64_t budget = slices.back().budget.timeBudget.budget;
+            runtime->addTelemetry(JS_TELEMETRY_GC_BUDGET_MS, t(budget));
+            if (budget == runtime->gc.defaultSliceBudget())
+                runtime->addTelemetry(JS_TELEMETRY_GC_ANIMATION_MS, t(sliceTime));
+        }
     }
 
     bool last = !runtime->gc.isIncrementalGCInProgress();

js/src/jsfriendapi.h

@@ -104,6 +104,8 @@ enum {
     JS_TELEMETRY_GC_REASON,
     JS_TELEMETRY_GC_IS_COMPARTMENTAL,
     JS_TELEMETRY_GC_MS,
+    JS_TELEMETRY_GC_BUDGET_MS,
+    JS_TELEMETRY_GC_ANIMATION_MS,
     JS_TELEMETRY_GC_MAX_PAUSE_MS,
     JS_TELEMETRY_GC_MARK_MS,
     JS_TELEMETRY_GC_SWEEP_MS,

js/src/jsgc.cpp

@@ -3004,7 +3004,7 @@ SliceBudget::describe(char* buffer, size_t maxlen) const
 {
     if (isUnlimited())
         return JS_snprintf(buffer, maxlen, "unlimited");
-    else if (deadline == 0)
+    else if (isWorkBudget())
         return JS_snprintf(buffer, maxlen, "work(%lld)", workBudget.budget);
     else
         return JS_snprintf(buffer, maxlen, "%lldms", timeBudget.budget);

js/xpconnect/src/XPCJSRuntime.cpp

@@ -3107,6 +3107,12 @@ AccumulateTelemetryCallback(int id, uint32_t sample, const char* key)
       case JS_TELEMETRY_GC_MS:
         Telemetry::Accumulate(Telemetry::GC_MS, sample);
         break;
+      case JS_TELEMETRY_GC_BUDGET_MS:
+        Telemetry::Accumulate(Telemetry::GC_BUDGET_MS, sample);
+        break;
+      case JS_TELEMETRY_GC_ANIMATION_MS:
+        Telemetry::Accumulate(Telemetry::GC_ANIMATION_MS, sample);
+        break;
       case JS_TELEMETRY_GC_MAX_PAUSE_MS:
         Telemetry::Accumulate(Telemetry::GC_MAX_PAUSE_MS, sample);
         break;

toolkit/components/telemetry/Histograms.json

@@ -275,6 +275,22 @@
     "n_buckets": 50,
     "description": "Time spent running JS GC (ms)"
   },
+  "GC_BUDGET_MS": {
+    "alert_emails": ["dev-telemetry-gc-alerts@mozilla.org"],
+    "expires_in_version": "never",
+    "kind": "linear",
+    "high": "100",
+    "n_buckets": 10,
+    "description": "Requested GC slice budget (ms)"
+  },
+  "GC_ANIMATION_MS": {
+    "alert_emails": ["dev-telemetry-gc-alerts@mozilla.org"],
+    "expires_in_version": "never",
+    "kind": "exponential",
+    "high": "10000",
+    "n_buckets": 50,
+    "description": "Time spent running JS GC when animating (ms)"
+  },
   "GC_MAX_PAUSE_MS": {
     "alert_emails": ["dev-telemetry-gc-alerts@mozilla.org"],
     "expires_in_version": "never",