core(driver): reduce required traceCategories again (#6271)

GoogleChrome · Oct 15, 2018 · 94d8e30 · 94d8e30
1 parent c3e15ca
commit 94d8e30
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Showing 2 changed files with 31 additions and 18 deletions.
diff --git a/lighthouse-core/gather/driver.js b/lighthouse-core/gather/driver.js
@@ -82,22 +82,38 @@ class Driver {
 
   static get traceCategories() {
     return [
-      '-*', // exclude default
-      'disabled-by-default-lighthouse', // used instead of 'toplevel' in Chrome 71+
+      // Exclude default categories. We'll be selective to minimize trace size
+      '-*',
+
+      // Used instead of 'toplevel' in Chrome 71+
+      'disabled-by-default-lighthouse',
+
+      // All compile/execute events are captured by parent events in devtools.timeline..
+      // But the v8 category provides some nice context for only <0.5% of the trace size
+      'v8',
+      // Same situation here. This category is there for RunMicrotasks only, but with other teams
+      // accidentally excluding microtasks, we don't want to assume a parent event will always exist
       'v8.execute',
-      'blink.console',
+
+      // For extracting UserTiming marks/measures
       'blink.user_timing',
-      'benchmark',
-      'loading',
-      'latencyInfo',
+
+      // Not mandatory but not used much
+      'blink.console',
+
+      // Most the events we need come in on these two
       'devtools.timeline',
       'disabled-by-default-devtools.timeline',
-      'disabled-by-default-devtools.timeline.frame',
+
+      // Up to 450 (https://goo.gl/rBfhn4) JPGs added to the trace
+      'disabled-by-default-devtools.screenshot',
+
+      // This doesn't add its own events, but adds a `stackTrace` property to devtools.timeline events
       'disabled-by-default-devtools.timeline.stack',
-      // Flipped off until bugs.chromium.org/p/v8/issues/detail?id=5820 is fixed in Stable
+
+      // CPU sampling profiler data only enabled for debugging purposes
       // 'disabled-by-default-v8.cpu_profiler',
       // 'disabled-by-default-v8.cpu_profiler.hires',
-      'disabled-by-default-devtools.screenshot',
     ];
   }
 

diff --git a/lighthouse-core/lib/task-groups.js b/lighthouse-core/lib/task-groups.js
@@ -31,8 +31,7 @@ const taskGroups = {
     label: 'Style & Layout',
     traceEventNames: [
       'ScheduleStyleRecalculation',
-      'RecalculateStyles',
-      'UpdateLayoutTree',
+      'UpdateLayoutTree', // previously RecalculateStyles
       'InvalidateLayout',
       'Layout',
     ],
@@ -42,15 +41,11 @@ const taskGroups = {
     label: 'Rendering',
     traceEventNames: [
       'Animation',
-      'RequestMainThreadFrame',
-      'ActivateLayerTree',
-      'DrawFrame',
       'HitTest',
       'PaintSetup',
       'Paint',
       'PaintImage',
-      'Rasterize',
-      'RasterTask',
+      'RasterTask', // Previously Rasterize
       'ScrollLayer',
       'UpdateLayer',
       'UpdateLayerTree',
@@ -81,9 +76,11 @@ const taskGroups = {
     id: 'garbageCollection',
     label: 'Garbage Collection',
     traceEventNames: [
-      'GCEvent',
-      'MinorGC',
+      'MinorGC', // Previously GCEvent
       'MajorGC',
+      'BlinkGC.AtomicPhase', // Previously ThreadState::performIdleLazySweep, ThreadState::completeSweep, BlinkGCMarking
+
+      // Kept for compatibility on older traces
       'ThreadState::performIdleLazySweep',
       'ThreadState::completeSweep',
       'BlinkGCMarking',