Linux perf support update.

src/base/platform/platform-posix.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Platform-specific code for POSIX goes here. This is not a platform on its
 // own, but contains the parts which are the same across the POSIX platforms
 // Linux, MacOS, FreeBSD, OpenBSD, NetBSD and QNX.
 
 #include <dlfcn.h>
 #include <errno.h>
 #include <limits.h>
 #include <pthread.h>
 #if defined(__DragonFly__) || defined(__FreeBSD__) || defined(__OpenBSD__)
 #include <pthread_np.h>  // for pthread_set_name_np
 #endif
 #include <sched.h>  // for sched_yield
 #include <time.h>
 #include <unistd.h>
 
 #include <sys/mman.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
+#include <sys/syscall.h>
 #include <sys/time.h>
 #include <sys/types.h>
-
 #if defined(__linux__)
 #include <sys/prctl.h>  // NOLINT, for prctl
 #endif
 #if defined(__APPLE__) || defined(__DragonFly__) || defined(__FreeBSD__) || \
     defined(__NetBSD__) || defined(__OpenBSD__)
 #include <sys/sysctl.h>  // NOLINT, for sysctl
 #endif
 
 #include <arpa/inet.h>
 #include <netdb.h>
@@ skipping 275 matching lines @@
   // NAN from math.h is defined in C99 and not in POSIX.
   return NAN;
 }
 
 
 int OS::GetCurrentProcessId() {
   return static_cast<int>(getpid());
 }
 
 
+int OS::GetCurrentThreadId() {
+  return static_cast<int>(syscall(SYS_gettid));
+}
+
+
 // ----------------------------------------------------------------------------
 // POSIX date/time support.
 //
 
 int OS::GetUserTime(uint32_t* secs,  uint32_t* usecs) {
   struct rusage usage;
 
   if (getrusage(RUSAGE_SELF, &usage) < 0) return -1;
   *secs = usage.ru_utime.tv_sec;
   *usecs = usage.ru_utime.tv_usec;
@@ skipping 386 matching lines @@
 
 void Thread::SetThreadLocal(LocalStorageKey key, void* value) {
   pthread_key_t pthread_key = LocalKeyToPthreadKey(key);
   int result = pthread_setspecific(pthread_key, value);
   ASSERT_EQ(0, result);
   USE(result);
 }
 
 
 } }  // namespace v8::base