Fix perfjit printf format for filename

src/perf-jit.cc

 // Copyright 2014 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
@@ skipping 20 matching lines @@
 #endif
 
 #include "src/perf-jit.h"
 
 
 namespace v8 {
 namespace internal {
 
 #ifdef __linux__
 
-const char PerfJitLogger::kFilenameFormatString[] = "perfjit.dump";
+const char PerfJitLogger::kFilenameFormatString[] = "perfjit-%d.dump";
 
 // Timestamp module name
 const char PerfJitLogger::kTraceClockDevice[] = "/dev/trace_clock";
 
 // Extra padding for the PID in the filename
 const int PerfJitLogger::kFilenameBufferPadding = 16;
 
 
 static clockid_t get_clockid(int fd) {
   return ((~(clockid_t) (fd) << 3) | 3);
@@ skipping 108 matching lines @@
   header.elf_mach = GetElfMach();
   header.pid = base::OS::GetCurrentProcessId();
   header.timestamp =
       static_cast<uint64_t>(base::OS::TimeCurrentMillis() * 1000.0);
   LogWriteBytes(reinterpret_cast<const char*>(&header), sizeof(header));
 }
 
 #endif  // defined(__linux__)
 
 } }   // namespace v8::internal