[perfetto,heap] Fix the order of GC trace event categories

This changes "v8[.gc],devtools.timeline" to "devtools.timeline,v8[.gc"
in some of the GC trace events because perfetto requires all categories
to be predefined.

Change-Id: I0e9a91c826f4e620f4946a1a96713aa2b45da26f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2193591
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67727}

src/heap/gc-tracer.h

@@ -26,7 +26,7 @@ inline BytesAndDuration MakeBytesAndDuration(uint64_t bytes, double duration) {
 enum ScavengeSpeedMode { kForAllObjects, kForSurvivedObjects };
 
 #define TRACE_GC_CATEGORIES \
-  TRACE_DISABLED_BY_DEFAULT("v8.gc") ",devtools.timeline"
+  "devtools.timeline," TRACE_DISABLED_BY_DEFAULT("v8.gc")
 
 #define TRACE_GC(tracer, scope_id)                             \
   GCTracer::Scope::ScopeId gc_tracer_scope_id(scope_id);       \

src/heap/heap.cc

@@ -1444,7 +1444,7 @@ void Heap::ReportExternalMemoryPressure() {
       isolate()->isolate_data()->external_memory_low_since_mark_compact_;
   int64_t limit = isolate()->isolate_data()->external_memory_limit_;
   TRACE_EVENT2(
-      "v8,devtools.timeline", "V8.ExternalMemoryPressure", "external_memory_mb",
+      "devtools.timeline,v8", "V8.ExternalMemoryPressure", "external_memory_mb",
       static_cast<int>((current - baseline) / MB), "external_memory_limit_mb",
       static_cast<int>((limit - baseline) / MB));
   if (current > baseline + external_memory_hard_limit()) {
@@ -3852,11 +3852,11 @@ void Heap::CheckMemoryPressure() {
   // the finalizers.
   memory_pressure_level_ = MemoryPressureLevel::kNone;
   if (memory_pressure_level == MemoryPressureLevel::kCritical) {
-    TRACE_EVENT0("v8,devtools.timeline", "V8.CheckMemoryPressure");
+    TRACE_EVENT0("devtools.timeline,v8", "V8.CheckMemoryPressure");
     CollectGarbageOnMemoryPressure();
   } else if (memory_pressure_level == MemoryPressureLevel::kModerate) {
     if (FLAG_incremental_marking && incremental_marking()->IsStopped()) {
-      TRACE_EVENT0("v8,devtools.timeline", "V8.CheckMemoryPressure");
+      TRACE_EVENT0("devtools.timeline,v8", "V8.CheckMemoryPressure");
       StartIncrementalMarking(kReduceMemoryFootprintMask,
                               GarbageCollectionReason::kMemoryPressure);
     }
@@ -3901,7 +3901,7 @@ void Heap::CollectGarbageOnMemoryPressure() {
 
 void Heap::MemoryPressureNotification(MemoryPressureLevel level,
                                       bool is_isolate_locked) {
-  TRACE_EVENT1("v8,devtools.timeline", "V8.MemoryPressureNotification", "level",
+  TRACE_EVENT1("devtools.timeline,v8", "V8.MemoryPressureNotification", "level",
                static_cast<int>(level));
   MemoryPressureLevel previous = memory_pressure_level_;
   memory_pressure_level_ = level;

src/tracing/trace-categories.h

@@ -33,7 +33,8 @@ PERFETTO_DEFINE_CATEGORIES(
     perfetto::Category("v8.execute"),
     perfetto::Category("v8.runtime"),
     perfetto::Category::Group("devtools.timeline,v8"),
-
+    perfetto::Category::Group("devtools.timeline,"
+                              TRACE_DISABLED_BY_DEFAULT("v8.gc")),
     perfetto::Category(TRACE_DISABLED_BY_DEFAULT("devtools.timeline")),
     perfetto::Category(TRACE_DISABLED_BY_DEFAULT("v8")),
     perfetto::Category(TRACE_DISABLED_BY_DEFAULT("v8.compile")),
@@ -49,9 +50,7 @@ PERFETTO_DEFINE_CATEGORIES(
     perfetto::Category(TRACE_DISABLED_BY_DEFAULT("v8.wasm")),
     perfetto::Category::Group("v8,devtools.timeline"),
     perfetto::Category::Group(TRACE_DISABLED_BY_DEFAULT("v8.turbofan") ","
-                              TRACE_DISABLED_BY_DEFAULT("v8.wasm")),
-    perfetto::Category::Group(TRACE_DISABLED_BY_DEFAULT("v8.gc")
-                              ",devtools.timeline"));
+                              TRACE_DISABLED_BY_DEFAULT("v8.wasm")));
 // clang-format on
 
 #endif  // defined(V8_USE_PERFETTO)