message: add (disabled) MSR write tracing on Linux
diff: @@ -39,6 +39,8 @@ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  #include <sys/cpuctl.h>
  #endif
  +#include <mutex>
  +
  namespace pcm {
  #ifdef _MSC_VER
  @@ -236,6 +238,11 @@ MsrHandle::~MsrHandle()
  int32 MsrHandle::write(uint64 msr_number, uint64 value)
  {
  +#if 0
  + static std::mutex m;
  + std::lock_guard<std::mutex> g(m);
  + std::cout << "DEBUG: writing MSR 0x" << std::hex << msr_number << " value 0x" << value << " on cpu " << std::dec << cpu_id << std::endl;
  +#endif
  return ::pwrite(fd, (const void *)&value, sizeof(uint64), msr_number);
  }
  