[maglev] Add trace events for maglev compilation

Similar to existing v8.compile trace events for Turbofan. Also, augment
both with flow events.

Bug: v8:7700
Change-Id: I1de96120ce1da98fe3ea1670b5f52cc7d65929cd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3918090
Commit-Queue: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Jakob Linke <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83425}

src/codegen/compiler.cc

@@ -1075,8 +1075,9 @@ bool CompileTurbofan_Concurrent(Isolate* isolate,
 
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
   RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeConcurrentPrepare);
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.OptimizeConcurrentPrepare");
+  TRACE_EVENT_WITH_FLOW0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                         "V8.OptimizeConcurrentPrepare", job.get(),
+                         TRACE_EVENT_FLAG_FLOW_OUT);
 
   if (!PrepareJobWithHandleScope(job.get(), isolate, compilation_info,
                                  ConcurrencyMode::kConcurrent)) {
@@ -1210,6 +1211,10 @@ MaybeHandle<CodeT> CompileMaglev(Isolate* isolate, Handle<JSFunction> function,
   auto job = maglev::MaglevCompilationJob::New(isolate, function);
 
   {
+    TRACE_EVENT_WITH_FLOW0(
+        TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+        IsSynchronous(mode) ? "V8.MaglevPrepare" : "V8.MaglevConcurrentPrepare",
+        job.get(), TRACE_EVENT_FLAG_FLOW_OUT);
     CompilerTracer::TraceStartMaglevCompile(isolate, function, mode);
     CompilationJob::Status status = job->PrepareJob(isolate);
     CHECK_EQ(status, CompilationJob::SUCCEEDED);  // TODO(v8:7700): Use status.
@@ -3915,8 +3920,9 @@ void Compiler::FinalizeTurbofanCompilationJob(TurbofanCompilationJob* job,
 
   TimerEventScope<TimerEventRecompileSynchronous> timer(isolate);
   RCS_SCOPE(isolate, RuntimeCallCounterId::kOptimizeConcurrentFinalize);
-  TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-               "V8.OptimizeConcurrentFinalize");
+  TRACE_EVENT_WITH_FLOW0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                         "V8.OptimizeConcurrentFinalize", job,
+                         TRACE_EVENT_FLAG_FLOW_IN);
 
   Handle<JSFunction> function = compilation_info->closure();
   Handle<SharedFunctionInfo> shared = compilation_info->shared_info();

src/compiler-dispatcher/optimizing-compile-dispatcher.cc

@@ -50,8 +50,10 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
                 RuntimeCallCounterId::kOptimizeBackgroundDispatcherJob);
 
       TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
-      TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
-                   "V8.OptimizeBackground");
+      TurbofanCompilationJob* job = dispatcher_->NextInput(&local_isolate);
+      TRACE_EVENT_WITH_FLOW0(
+          TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.OptimizeBackground", job,
+          TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT);
 
       if (dispatcher_->recompilation_delay_ != 0) {
         base::OS::Sleep(base::TimeDelta::FromMilliseconds(
@@ -62,8 +64,7 @@ class OptimizingCompileDispatcher::CompileTask : public CancelableTask {
       // code space in order to be able to get a bytecode array from a baseline
       // code. See SharedFunctionInfo::GetActiveBytecodeArray() for details.
       RwxMemoryWriteScope::SetDefaultPermissionsForNewThread();
-      dispatcher_->CompileNext(dispatcher_->NextInput(&local_isolate),
-                               &local_isolate);
+      dispatcher_->CompileNext(job, &local_isolate);
     }
     {
       base::MutexGuard lock_guard(&dispatcher_->ref_count_mutex_);

src/maglev/maglev-concurrent-dispatcher.cc

@@ -138,6 +138,9 @@ class MaglevConcurrentDispatcher::JobTask final : public v8::JobTask {
       std::unique_ptr<MaglevCompilationJob> job;
       if (!incoming_queue()->Dequeue(&job)) break;
       DCHECK_NOT_NULL(job);
+      TRACE_EVENT_WITH_FLOW0(
+          TRACE_DISABLED_BY_DEFAULT("v8.compile"), "V8.MaglevBackground",
+          job.get(), TRACE_EVENT_FLAG_FLOW_IN | TRACE_EVENT_FLAG_FLOW_OUT);
       RuntimeCallStats* rcs = nullptr;  // TODO(v8:7700): Implement.
       CompilationJob::Status status = job->ExecuteJob(rcs, &local_isolate);
       CHECK_EQ(status, CompilationJob::SUCCEEDED);
@@ -192,6 +195,9 @@ void MaglevConcurrentDispatcher::FinalizeFinishedJobs() {
   while (!outgoing_queue_.IsEmpty()) {
     std::unique_ptr<MaglevCompilationJob> job;
     outgoing_queue_.Dequeue(&job);
+    TRACE_EVENT_WITH_FLOW0(TRACE_DISABLED_BY_DEFAULT("v8.compile"),
+                           "V8.MaglevConcurrentFinalize", job.get(),
+                           TRACE_EVENT_FLAG_FLOW_IN);
     Compiler::FinalizeMaglevCompilationJob(job.get(), isolate_);
   }
 }