Disable jit dump output by default

runtime/vm/os_linux.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"
 #if defined(TARGET_OS_LINUX)
 
 #include "vm/os.h"
 
 #include <errno.h>  // NOLINT
@@ skipping 23 matching lines @@
 // Linux CodeObservers.
 
 DEFINE_FLAG(bool, generate_gdb_symbols, false,
     "Generate symbols of generated dart functions for debugging with GDB");
 DEFINE_FLAG(bool, generate_perf_events_symbols, false,
     "Generate events symbols for profiling with perf");
 DEFINE_FLAG(bool, ll_prof, false,
     "Generate compiled code log file for processing with ll_prof.py.");
 DEFINE_FLAG(charp, generate_pprof_symbols, NULL,
     "Writes pprof events symbols to the provided file");
-DEFINE_FLAG(bool, generate_perf_jitdump, true,
+DEFINE_FLAG(bool, generate_perf_jitdump, false,
     "Writes jitdump data for profiling with perf annotate");
 
 class LowLevelProfileCodeObserver : public CodeObserver {
  public:
   LowLevelProfileCodeObserver() {
     Dart_FileOpenCallback file_open = Isolate::file_open_callback();
     if (file_open == NULL) {
       return;
     }
     const char* filename = "v8.log.ll";
@@ skipping 714 matching lines @@
 }
 
 
 void OS::Exit(int code) {
   exit(code);
 }
 
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_LINUX)