Improve sampler resolution on Linux.

test/cctest/test-log.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 //
 // Tests of logging functions from log.h
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 #ifdef __linux__
 #include <math.h>
 #include <pthread.h>
 #include <signal.h>
@@ skipping 319 matching lines @@
   CompileAndRunScript("var a = (function(x) { return x + 1; })(10);");
 
   // No new data beyond last retrieved position.
   CHECK_EQ(0, matcher.GetNextChunk());
 
   // Check that profiling can be resumed again.
   CheckThatProfilerWorks(&matcher);
 }
 
 
-// Profiling multiple threads that use V8 is currently only available on Linux.
-#ifdef __linux__
+// BUG(913). Need to implement support for profiling multiple VM threads.
+#if 0
 
 namespace {
 
 class LoopingThread : public v8::internal::Thread {
  public:
   LoopingThread()
       : v8::internal::Thread(),
         semaphore_(v8::internal::OS::CreateSemaphore(0)),
         run_(true) {
   }
@@ skipping 837 matching lines @@
   // Make sure that all log data is written prior crash due to CHECK failure.
   fflush(stdout);
   CHECK(results_equal);
 
   env->Exit();
   Logger::TearDown();
   i::FLAG_always_compact = saved_always_compact;
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING