Linux perf integration with the new support for JIT.

Difference from --perf-basic-prof:
- correctly attributes samples when code space gets reused (when unused code object dies and a new code objects is allocated at the same place).
- outputs compiled machine code for instruction-level profile.

Just like --perf-basic-prof, the file writer is not synchronized (even worse, there is a per-isolate file handle), so we will run into trouble with multiple isolates. However, this patch is still an improvement on --perf-basic-prof, and it should be fine to replace ll-prof.

The patch also introduces experimental support for debug info, but it does not seem to be picked by the perf tool.

Usage:

You need the perf tool from Linux kernel >4.5. Then run:

$ perf record -k mono d8 --perf-prof <your JS file>
$ perf inject -j -i perf.data -o perf.data.jitted
$ perf report -i perf.data.jitted

Some explanations:
The "-k mono" switch from "perf record" tells the perf tool to use the monotonic clock for perf sample timestamping. The "perf inject -j" command injects the collected code events into the perf data file, writing the output into perf.data.jitted. The perf report command then creates the report.

Review URL: https://codereview.chromium.org/1809203007

Cr-Commit-Position: refs/heads/master@{#35091}

BUILD.gn

@@ -1198,6 +1198,8 @@ source_set("v8_base") {
     "src/parsing/token.h",
     "src/pending-compilation-error-handler.cc",
     "src/pending-compilation-error-handler.h",
+    "src/perf-jit.cc",
+    "src/perf-jit.h",
     "src/profiler/allocation-tracker.cc",
     "src/profiler/allocation-tracker.h",
     "src/profiler/circular-queue-inl.h",

src/base/platform/time.cc

@@ -520,14 +520,6 @@ bool TimeTicks::IsHighResolutionClockWorking() {
   return high_res_tick_clock.Pointer()->IsHighResolution();
 }
 
-
-// static
-TimeTicks TimeTicks::KernelTimestampNow() { return TimeTicks(0); }
-
-
-// static
-bool TimeTicks::KernelTimestampAvailable() { return false; }
-
 #else  // V8_OS_WIN
 
 TimeTicks TimeTicks::Now() {
@@ -566,82 +558,6 @@ bool TimeTicks::IsHighResolutionClockWorking() {
   return true;
 }
 
-
-#if V8_OS_LINUX
-
-class KernelTimestampClock {
- public:
-  KernelTimestampClock() : clock_fd_(-1), clock_id_(kClockInvalid) {
-    clock_fd_ = open(kTraceClockDevice, O_RDONLY);
-    if (clock_fd_ == -1) {
-      return;
-    }
-    clock_id_ = get_clockid(clock_fd_);
-  }
-
-  virtual ~KernelTimestampClock() {
-    if (clock_fd_ != -1) {
-      close(clock_fd_);
-    }
-  }
-
-  int64_t Now() {
-    if (clock_id_ == kClockInvalid) {
-      return 0;
-    }
-
-    struct timespec ts;
-
-    clock_gettime(clock_id_, &ts);
-    return ((int64_t)ts.tv_sec * kNsecPerSec) + ts.tv_nsec;
-  }
-
-  bool Available() { return clock_id_ != kClockInvalid; }
-
- private:
-  static const clockid_t kClockInvalid = -1;
-  static const char kTraceClockDevice[];
-  static const uint64_t kNsecPerSec = 1000000000;
-
-  int clock_fd_;
-  clockid_t clock_id_;
-
-  static int get_clockid(int fd) { return ((~(clockid_t)(fd) << 3) | 3); }
-};
-
-
-// Timestamp module name
-const char KernelTimestampClock::kTraceClockDevice[] = "/dev/trace_clock";
-
-#else
-
-class KernelTimestampClock {
- public:
-  KernelTimestampClock() {}
-
-  int64_t Now() { return 0; }
-  bool Available() { return false; }
-};
-
-#endif  // V8_OS_LINUX
-
-static LazyStaticInstance<KernelTimestampClock,
-                          DefaultConstructTrait<KernelTimestampClock>,
-                          ThreadSafeInitOnceTrait>::type kernel_tick_clock =
-    LAZY_STATIC_INSTANCE_INITIALIZER;
-
-
-// static
-TimeTicks TimeTicks::KernelTimestampNow() {
-  return TimeTicks(kernel_tick_clock.Pointer()->Now());
-}
-
-
-// static
-bool TimeTicks::KernelTimestampAvailable() {
-  return kernel_tick_clock.Pointer()->Available();
-}
-
 #endif  // V8_OS_WIN
 
 }  // namespace base

src/base/platform/time.h

@@ -318,13 +318,6 @@ class TimeTicks final {
   // Returns true if the high-resolution clock is working on this system.
   static bool IsHighResolutionClockWorking();
 
-  // Returns Linux kernel timestamp for generating profiler events. This method
-  // returns null TimeTicks if the kernel cannot provide the timestamps (e.g.,
-  // on non-Linux OS or if the kernel module for timestamps is not loaded).
-
-  static TimeTicks KernelTimestampNow();
-  static bool KernelTimestampAvailable();
-
   // Returns true if this object has not been initialized.
   bool IsNull() const { return ticks_ == 0; }
 

src/flag-definitions.h

@@ -1024,6 +1024,11 @@ DEFINE_NEG_IMPLICATION(perf_basic_prof, compact_code_space)
 DEFINE_BOOL(perf_basic_prof_only_functions, false,
             "Only report function code ranges to perf (i.e. no stubs).")
 DEFINE_IMPLICATION(perf_basic_prof_only_functions, perf_basic_prof)
+DEFINE_BOOL(perf_prof, false,
+            "Enable perf linux profiler (experimental annotate support).")
+DEFINE_NEG_IMPLICATION(perf_prof, compact_code_space)
+DEFINE_BOOL(perf_prof_debug_info, false,
+            "Enable debug info for perf linux profiler (experimental).")
 DEFINE_STRING(gc_fake_mmap, "/tmp/__v8_gc__",
               "Specify the name of the file for fake gc mmap used in ll_prof")
 DEFINE_BOOL(log_internal_timer_events, false, "Time internal events.")

src/log-utils.h

@@ -30,7 +30,7 @@ class Log {
   static bool InitLogAtStart() {
     return FLAG_log || FLAG_log_api || FLAG_log_code || FLAG_log_gc ||
            FLAG_log_handles || FLAG_log_suspect || FLAG_log_regexp ||
-           FLAG_ll_prof || FLAG_perf_basic_prof ||
+           FLAG_ll_prof || FLAG_perf_basic_prof || FLAG_perf_prof ||
            FLAG_log_internal_timer_events || FLAG_prof_cpp;
   }
 

src/log.cc

@@ -18,6 +18,7 @@
 #include "src/log-inl.h"
 #include "src/log-utils.h"
 #include "src/macro-assembler.h"
+#include "src/perf-jit.h"
 #include "src/profiler/cpu-profiler.h"
 #include "src/runtime-profiler.h"
 #include "src/string-stream.h"
@@ -730,19 +731,18 @@ void Profiler::Run() {
 //
 
 Logger::Logger(Isolate* isolate)
-  : isolate_(isolate),
-    ticker_(NULL),
-    profiler_(NULL),
-    log_events_(NULL),
-    is_logging_(false),
-    log_(new Log(this)),
-    perf_basic_logger_(NULL),
-    ll_logger_(NULL),
-    jit_logger_(NULL),
-    listeners_(5),
-    is_initialized_(false) {
-}
-
+    : isolate_(isolate),
+      ticker_(NULL),
+      profiler_(NULL),
+      log_events_(NULL),
+      is_logging_(false),
+      log_(new Log(this)),
+      perf_basic_logger_(NULL),
+      perf_jit_logger_(NULL),
+      ll_logger_(NULL),
+      jit_logger_(NULL),
+      listeners_(5),
+      is_initialized_(false) {}
 
 Logger::~Logger() {
   delete log_;
@@ -1797,6 +1797,11 @@ bool Logger::SetUp(Isolate* isolate) {
     addCodeEventListener(perf_basic_logger_);
   }
 
+  if (FLAG_perf_prof) {
+    perf_jit_logger_ = new PerfJitLogger();
+    addCodeEventListener(perf_jit_logger_);
+  }
+
   if (FLAG_ll_prof) {
     ll_logger_ = new LowLevelLogger(log_file_name.str().c_str());
     addCodeEventListener(ll_logger_);
@@ -1865,6 +1870,12 @@ FILE* Logger::TearDown() {
     perf_basic_logger_ = NULL;
   }
 
+  if (perf_jit_logger_) {
+    removeCodeEventListener(perf_jit_logger_);
+    delete perf_jit_logger_;
+    perf_jit_logger_ = NULL;
+  }
+
   if (ll_logger_) {
     removeCodeEventListener(ll_logger_);
     delete ll_logger_;

src/log.h

@@ -145,6 +145,7 @@ struct TickSample;
 class JitLogger;
 class PerfBasicLogger;
 class LowLevelLogger;
+class PerfJitLogger;
 class Sampler;
 
 class Logger {
@@ -393,6 +394,7 @@ class Logger {
   bool is_logging_;
   Log* log_;
   PerfBasicLogger* perf_basic_logger_;
+  PerfJitLogger* perf_jit_logger_;
   LowLevelLogger* ll_logger_;
   JitLogger* jit_logger_;
   List<CodeEventListener*> listeners_;

src/perf-jit.cc

@@ -0,0 +1,321 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "src/perf-jit.h"
+
+#include "src/assembler.h"
+#include "src/objects-inl.h"
+
+#if V8_OS_LINUX
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#endif  // V8_OS_LINUX
+
+namespace v8 {
+namespace internal {
+
+#if V8_OS_LINUX
+
+struct PerfJitHeader {
+  uint32_t magic_;
+  uint32_t version_;
+  uint32_t size_;
+  uint32_t elf_mach_target_;
+  uint32_t reserved_;
+  uint32_t process_id_;
+  uint64_t time_stamp_;
+  uint64_t flags_;
+
+  static const uint32_t kMagic = 0x4A695444;
+  static const uint32_t kVersion = 1;
+};
+
+struct PerfJitBase {
+  enum PerfJitEvent { kLoad = 0, kMove = 1, kDebugInfo = 2, kClose = 3 };
+
+  uint32_t event_;
+  uint32_t size_;
+  uint64_t time_stamp_;
+};
+
+struct PerfJitCodeLoad : PerfJitBase {
+  uint32_t process_id_;
+  uint32_t thread_id_;
+  uint64_t vma_;
+  uint64_t code_address_;
+  uint64_t code_size_;
+  uint64_t code_id_;
+};
+
+struct PerfJitDebugEntry {
+  uint64_t address_;
+  int line_number_;
+  int column_;
+  // Followed by null-terminated name or \0xff\0 if same as previous.
+};
+
+struct PerfJitCodeDebugInfo : PerfJitBase {
+  uint64_t address_;
+  uint64_t entry_count_;
+  // Followed by entry_count_ instances of PerfJitDebugEntry.
+};
+
+const char PerfJitLogger::kFilenameFormatString[] = "./jit-%d.dump";
+
+// Extra padding for the PID in the filename
+const int PerfJitLogger::kFilenameBufferPadding = 16;
+
+void PerfJitLogger::OpenJitDumpFile() {
+  // Open the perf JIT dump file.
+  perf_output_handle_ = nullptr;
+
+  int bufferSize = sizeof(kFilenameFormatString) + kFilenameBufferPadding;
+  ScopedVector<char> perf_dump_name(bufferSize);
+  int size = SNPrintF(perf_dump_name, kFilenameFormatString,
+                      base::OS::GetCurrentProcessId());
+  CHECK_NE(size, -1);
+
+  int fd = open(perf_dump_name.start(), O_CREAT | O_TRUNC | O_RDWR, 0666);
+  if (fd == -1) return;
+
+  marker_address_ = OpenMarkerFile(fd);
+  if (marker_address_ == nullptr) return;
+
+  perf_output_handle_ = fdopen(fd, "w+");
+  if (perf_output_handle_ == nullptr) return;
+
+  setvbuf(perf_output_handle_, NULL, _IOFBF, kLogBufferSize);
+}
+
+void PerfJitLogger::CloseJitDumpFile() {
+  if (perf_output_handle_ == nullptr) return;
+  fclose(perf_output_handle_);
+  perf_output_handle_ = nullptr;
+}
+
+void* PerfJitLogger::OpenMarkerFile(int fd) {
+  long page_size = sysconf(_SC_PAGESIZE);  // NOLINT(runtime/int)
+  if (page_size == -1) return nullptr;
+
+  // Mmap the file so that there is a mmap record in the perf_data file.
+  //
+  // The map must be PROT_EXEC to ensure it is not ignored by perf record.
+  void* marker_address =
+      mmap(nullptr, page_size, PROT_READ | PROT_EXEC, MAP_PRIVATE, fd, 0);
+  return (marker_address == MAP_FAILED) ? nullptr : marker_address;
+}
+
+void PerfJitLogger::CloseMarkerFile(void* marker_address) {
+  if (marker_address == nullptr) return;
+  long page_size = sysconf(_SC_PAGESIZE);  // NOLINT(runtime/int)
+  if (page_size == -1) return;
+  munmap(marker_address, page_size);
+}
+
+PerfJitLogger::PerfJitLogger()
+    : perf_output_handle_(nullptr), code_index_(0), marker_address_(nullptr) {
+  OpenJitDumpFile();
+  if (perf_output_handle_ == nullptr) return;
+  LogWriteHeader();
+}
+
+PerfJitLogger::~PerfJitLogger() { CloseJitDumpFile(); }
+
+uint64_t PerfJitLogger::GetTimestamp() {
+  struct timespec ts;
+  int result = clock_gettime(CLOCK_MONOTONIC, &ts);
+  DCHECK_EQ(0, result);
+  USE(result);
+  static const uint64_t kNsecPerSec = 1000000000;
+  return (ts.tv_sec * kNsecPerSec) + ts.tv_nsec;
+}
+
+void PerfJitLogger::LogRecordedBuffer(AbstractCode* abstract_code,
+                                      SharedFunctionInfo* shared,
+                                      const char* name, int length) {
+  if (perf_output_handle_ == nullptr) return;
+  if (FLAG_perf_basic_prof_only_functions &&
+      (abstract_code->kind() != AbstractCode::FUNCTION &&
+       abstract_code->kind() != AbstractCode::INTERPRETED_FUNCTION &&
+       abstract_code->kind() != AbstractCode::OPTIMIZED_FUNCTION)) {
+    return;
+  }
+
+  // We only support non-interpreted functions.
+  if (!abstract_code->IsCode()) return;
+  Code* code = abstract_code->GetCode();
+  DCHECK(code->instruction_start() == code->address() + Code::kHeaderSize);
+
+  const char* code_name = name;
+  uint8_t* code_pointer = reinterpret_cast<uint8_t*>(code->instruction_start());
+  uint32_t code_size = code->is_crankshafted() ? code->safepoint_table_offset()
+                                               : code->instruction_size();
+
+  static const char string_terminator[] = "\0";
+
+  PerfJitCodeLoad code_load;
+  code_load.event_ = PerfJitCodeLoad::kLoad;
+  code_load.size_ = sizeof(code_load) + length + 1 + code_size;
+  code_load.time_stamp_ = GetTimestamp();
+  code_load.process_id_ =
+      static_cast<uint32_t>(base::OS::GetCurrentProcessId());
+  code_load.thread_id_ = static_cast<uint32_t>(base::OS::GetCurrentThreadId());
+  code_load.vma_ = 0x0;  //  Our addresses are absolute.
+  code_load.code_address_ = reinterpret_cast<uint64_t>(code_pointer);
+  code_load.code_size_ = code_size;
+  code_load.code_id_ = code_index_;
+
+  code_index_++;
+
+  LogWriteBytes(reinterpret_cast<const char*>(&code_load), sizeof(code_load));
+  LogWriteBytes(code_name, length);
+  LogWriteBytes(string_terminator, 1);
+  LogWriteBytes(reinterpret_cast<const char*>(code_pointer), code_size);
+
+  if (FLAG_perf_prof_debug_info) {
+    LogWriteDebugInfo(code, shared);
+  }
+}
+
+void PerfJitLogger::LogWriteDebugInfo(Code* code, SharedFunctionInfo* shared) {
+  // Compute the entry count and get the name of the script.
+  uint32_t entry_count = 0;
+  for (RelocIterator it(code, RelocInfo::kPositionMask); !it.done();
+       it.next()) {
+    entry_count++;
+  }
+  if (entry_count == 0) return;
+  Handle<Script> script(Script::cast(shared->script()));
+  Handle<Object> name_or_url(Script::GetNameOrSourceURL(script));
+
+  int name_length = 0;
+  base::SmartArrayPointer<char> name_string;
+  if (name_or_url->IsString()) {
+    name_string =
+        Handle<String>::cast(name_or_url)
+            ->ToCString(DISALLOW_NULLS, FAST_STRING_TRAVERSAL, &name_length);
+    DCHECK_EQ(0, name_string.get()[name_length]);
+  } else {
+    const char unknown[] = "<unknown>";
+    name_length = static_cast<int>(strlen(unknown));
+    char* buffer = NewArray<char>(name_length);
+    base::OS::StrNCpy(buffer, name_length + 1, unknown,
+                      static_cast<size_t>(name_length));
+    name_string = base::SmartArrayPointer<char>(buffer);
+  }
+  DCHECK_EQ(name_length, strlen(name_string.get()));
+
+  PerfJitCodeDebugInfo debug_info;
+
+  debug_info.event_ = PerfJitCodeLoad::kDebugInfo;
+  debug_info.time_stamp_ = GetTimestamp();
+  debug_info.address_ = reinterpret_cast<uint64_t>(code->instruction_start());
+  debug_info.entry_count_ = entry_count;
+
+  uint32_t size = sizeof(debug_info);
+  // Add the sizes of fixed parts of entries.
+  size += entry_count * sizeof(PerfJitDebugEntry);
+  // Add the size of the name after the first entry.
+  size += static_cast<uint32_t>(name_length) + 1;
+  // Add the sizes of the links to previous name (\0xff\0).
+  size += (entry_count - 1) * 2;
+
+  int padding = ((size + 7) & (~7)) - size;
+
+  debug_info.size_ = size + padding;
+
+  LogWriteBytes(reinterpret_cast<const char*>(&debug_info), sizeof(debug_info));
+
+  int script_line_offset = script->line_offset();
+  Handle<FixedArray> line_ends(FixedArray::cast(script->line_ends()));
+
+  bool is_first = true;
+  for (RelocIterator it(code, RelocInfo::kPositionMask); !it.done();
+       it.next()) {
+    int position = static_cast<int>(it.rinfo()->data());
+    int line_number = Script::GetLineNumber(script, position);
+    // Compute column.
+    int relative_line_number = line_number - script_line_offset;
+    int start =
+        (relative_line_number == 0)
+            ? 0
+            : Smi::cast(line_ends->get(relative_line_number - 1))->value() + 1;
+    int column_offset = position - start;
+    if (relative_line_number == 0) {
+      // For the case where the code is on the same line as the script tag.
+      column_offset += script->column_offset();
+    }
+
+    PerfJitDebugEntry entry;
+    entry.address_ = reinterpret_cast<uint64_t>(it.rinfo()->pc());
+    entry.line_number_ = line_number;
+    entry.column_ = column_offset;
+    LogWriteBytes(reinterpret_cast<const char*>(&entry), sizeof(entry));
+
+    if (is_first) {
+      is_first = false;
+      LogWriteBytes(name_string.get(), name_length + 1);
+    } else {
+      LogWriteBytes("\xff", 2);
+    }
+  }
+  char padding_bytes[] = "\0\0\0\0\0\0\0\0";
+  LogWriteBytes(padding_bytes, padding);
+}
+
+void PerfJitLogger::CodeMoveEvent(AbstractCode* from, Address to) {
+  // Code relocation not supported.
+  UNREACHABLE();
+}
+
+void PerfJitLogger::LogWriteBytes(const char* bytes, int size) {
+  size_t rv = fwrite(bytes, 1, size, perf_output_handle_);
+  DCHECK(static_cast<size_t>(size) == rv);
+  USE(rv);
+}
+
+void PerfJitLogger::LogWriteHeader() {
+  DCHECK(perf_output_handle_ != NULL);
+  PerfJitHeader header;
+
+  header.magic_ = PerfJitHeader::kMagic;
+  header.version_ = PerfJitHeader::kVersion;
+  header.size_ = sizeof(header);
+  header.elf_mach_target_ = GetElfMach();
+  header.reserved_ = 0xdeadbeef;
+  header.process_id_ = base::OS::GetCurrentProcessId();
+  header.time_stamp_ =
+      static_cast<uint64_t>(base::OS::TimeCurrentMillis() * 1000.0);
+  header.flags_ = 0;
+
+  LogWriteBytes(reinterpret_cast<const char*>(&header), sizeof(header));
+}
+
+#endif  // V8_OS_LINUX
+}  // namespace internal
+}  // namespace v8

src/perf-jit.h

@@ -0,0 +1,118 @@
+// Copyright 2016 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_PERF_JIT_H_
+#define V8_PERF_JIT_H_
+
+#include "src/log.h"
+
+namespace v8 {
+namespace internal {
+
+#if V8_OS_LINUX
+
+// Linux perf tool logging support
+class PerfJitLogger : public CodeEventLogger {
+ public:
+  PerfJitLogger();
+  virtual ~PerfJitLogger();
+
+  void CodeMoveEvent(AbstractCode* from, Address to) override;
+  void CodeDisableOptEvent(AbstractCode* code,
+                           SharedFunctionInfo* shared) override {}
+
+ private:
+  void OpenJitDumpFile();
+  void CloseJitDumpFile();
+  void* OpenMarkerFile(int fd);
+  void CloseMarkerFile(void* marker_address);
+
+  uint64_t GetTimestamp();
+  void LogRecordedBuffer(AbstractCode* code, SharedFunctionInfo* shared,
+                         const char* name, int length) override;
+
+  // Extension added to V8 log file name to get the low-level log name.
+  static const char kFilenameFormatString[];
+  static const int kFilenameBufferPadding;
+
+  // File buffer size of the low-level log. We don't use the default to
+  // minimize the associated overhead.
+  static const int kLogBufferSize = 2 * MB;
+
+  void LogWriteBytes(const char* bytes, int size);
+  void LogWriteHeader();
+  void LogWriteDebugInfo(Code* code, SharedFunctionInfo* shared);
+
+  static const uint32_t kElfMachIA32 = 3;
+  static const uint32_t kElfMachX64 = 62;
+  static const uint32_t kElfMachARM = 40;
+  static const uint32_t kElfMachMIPS = 10;
+
+  uint32_t GetElfMach() {
+#if V8_TARGET_ARCH_IA32
+    return kElfMachIA32;
+#elif V8_TARGET_ARCH_X64
+    return kElfMachX64;
+#elif V8_TARGET_ARCH_ARM
+    return kElfMachARM;
+#elif V8_TARGET_ARCH_MIPS
+    return kElfMachMIPS;
+#else
+    UNIMPLEMENTED();
+    return 0;
+#endif
+  }
+
+  FILE* perf_output_handle_;
+  uint64_t code_index_;
+  void* marker_address_;
+};
+
+#else
+
+// PerfJitLogger is only implemented on Linux
+class PerfJitLogger : public CodeEventLogger {
+ public:
+  void CodeMoveEvent(AbstractCode* from, Address to) override {
+    UNIMPLEMENTED();
+  }
+
+  void CodeDisableOptEvent(AbstractCode* code,
+                           SharedFunctionInfo* shared) override {
+    UNIMPLEMENTED();
+  }
+
+  void LogRecordedBuffer(AbstractCode* code, SharedFunctionInfo* shared,
+                         const char* name, int length) override {
+    UNIMPLEMENTED();
+  }
+};
+
+#endif  // V8_OS_LINUX
+}  // namespace internal
+}  // namespace v8
+#endif

tools/gyp/v8.gyp

@@ -1026,6 +1026,8 @@
         '../../src/parsing/token.h',
         '../../src/pending-compilation-error-handler.cc',
         '../../src/pending-compilation-error-handler.h',
+        '../../src/perf-jit.cc',
+        '../../src/perf-jit.h',
         '../../src/profiler/allocation-tracker.cc',
         '../../src/profiler/allocation-tracker.h',
         '../../src/profiler/circular-queue-inl.h',