Support profiling based on linux kernel performance events.

src/log.cc

Index: src/log.cc
diff --git a/src/log.cc b/src/log.cc
index 4230cba91ada710b9e0372cf86f70c5e3a88202a..98e9b92873665d53d91ca05c90875a0b72724a45 100644
--- a/src/log.cc
+++ b/src/log.cc
@@ -765,6 +765,7 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag,
     msg.Append(*p);
   }
   msg.Append('"');
+  LowLevelCodeCreateEvent(code, &msg);
   if (FLAG_compress_log) {
     ASSERT(compression_helper_ != NULL);
     if (!compression_helper_->HandleMessage(&msg)) return;
@@ -784,6 +785,7 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag, Code* code, String* name) {
   msg.Append("%s,%s,", log_events_[CODE_CREATION_EVENT], log_events_[tag]);
   msg.AppendAddress(code->address());
   msg.Append(",%d,\"%s\"", code->ExecutableSize(), *str);
+  LowLevelCodeCreateEvent(code, &msg);
   if (FLAG_compress_log) {
     ASSERT(compression_helper_ != NULL);
     if (!compression_helper_->HandleMessage(&msg)) return;
@@ -808,6 +810,7 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag,
   msg.AppendAddress(code->address());
   msg.Append(",%d,\"%s %s:%d\"",
              code->ExecutableSize(), *str, *sourcestr, line);
+  LowLevelCodeCreateEvent(code, &msg);
   if (FLAG_compress_log) {
     ASSERT(compression_helper_ != NULL);
     if (!compression_helper_->HandleMessage(&msg)) return;
@@ -825,6 +828,7 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag, Code* code, int args_count) {
   msg.Append("%s,%s,", log_events_[CODE_CREATION_EVENT], log_events_[tag]);
   msg.AppendAddress(code->address());
   msg.Append(",%d,\"args_count: %d\"", code->ExecutableSize(), args_count);
+  LowLevelCodeCreateEvent(code, &msg);
   if (FLAG_compress_log) {
     ASSERT(compression_helper_ != NULL);
     if (!compression_helper_->HandleMessage(&msg)) return;
@@ -835,6 +839,17 @@ void Logger::CodeCreateEvent(LogEventsAndTags tag, Code* code, int args_count) {
 }
 
 
+void Logger::CodeMovingGCEvent() {
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  if (!Log::IsEnabled() || !FLAG_log_code || !FLAG_ll_prof) return;
+  LogMessageBuilder msg;
+  msg.Append("%s\n", log_events_[CODE_MOVING_GC]);
+  msg.WriteToLogFile();
+  OS::SignalCodeMovingGC();
+#endif
+}
+
+
 void Logger::RegExpCodeCreateEvent(Code* code, String* source) {
 #ifdef ENABLE_LOGGING_AND_PROFILING
   if (!Log::IsEnabled() || !FLAG_log_code) return;
@@ -845,6 +860,7 @@ void Logger::RegExpCodeCreateEvent(Code* code, String* source) {
   msg.Append(",%d,\"", code->ExecutableSize());
   msg.AppendDetailed(source, false);
   msg.Append('\"');
+  LowLevelCodeCreateEvent(code, &msg);
   if (FLAG_compress_log) {
     ASSERT(compression_helper_ != NULL);
     if (!compression_helper_->HandleMessage(&msg)) return;
@@ -1340,6 +1356,34 @@ void Logger::LogCodeObject(Object* object) {
 }
 
 
+void Logger::LogCodeInfo() {
+#ifdef ENABLE_LOGGING_AND_PROFILING
+  if (!Log::IsEnabled() || !FLAG_log_code || !FLAG_ll_prof) return;
+#if V8_TARGET_ARCH_IA32
+  const char arch[] = "ia32";
+#elif V8_TARGET_ARCH_X64
+  const char arch[] = "x64";
+#elif V8_TARGET_ARCH_ARM
+  const char arch[] = "arm";
+#else
+  const char arch[] = "unknown";
+#endif
+  LogMessageBuilder msg;
+  msg.Append("code-info,%s,%d\n", arch, Code::kHeaderSize);
+  msg.WriteToLogFile();
+#endif  // ENABLE_LOGGING_AND_PROFILING
+}
+
+
+void Logger::LowLevelCodeCreateEvent(Code* code, LogMessageBuilder* msg) {
+  if (!FLAG_ll_prof || Log::output_code_handle_ == NULL) return;
+  int pos = static_cast<int>(ftell(Log::output_code_handle_));
+  fwrite(code->instruction_start(), 1, code->instruction_size(),
+         Log::output_code_handle_);
+  msg->Append(",%d", pos);
+}
+
+
 void Logger::LogCodeObjects() {
   AssertNoAllocation no_alloc;
   HeapIterator iterator;
@@ -1451,6 +1495,12 @@ bool Logger::Setup() {
   // --prof implies --log-code.
   if (FLAG_prof) FLAG_log_code = true;
 
+  // --ll-prof implies --log-code and --log-snapshot-positions.
+  if (FLAG_ll_prof) {
+    FLAG_log_code = true;
+    FLAG_log_snapshot_positions = true;
+  }
+
   // --prof_lazy controls --log-code, implies --noprof_auto.
   if (FLAG_prof_lazy) {
     FLAG_log_code = false;
@@ -1512,6 +1562,8 @@ bool Logger::Setup() {
 
   ASSERT(VMState::is_outermost_external());
 
+  if (FLAG_ll_prof) LogCodeInfo();
+
   ticker_ = new Ticker(kSamplingIntervalMs);
 
   if (FLAG_sliding_state_window && sliding_state_window_ == NULL) {