SUGGESTED FIX

Finally, we decided to use fast posix clock implementation for "other" threads
as well, not for current thread only.
Please, see the webrev hs_mm.Nov16.tar.gz in attachmnets.
                                     

EVALUATION

I have some doubt that maybe we need to use the posix clock implementation
on Linux for ThreadMXBean.getThreadCpuTime() as well.
Then fast posix clock implementation can be used for any thread, not for current only.
                                     

SUGGESTED FIX

The suggested fix is to update the src/os/linux/vm/os_linux.cpp as follows:

% sccs sccsdiff -c -r1.242 -r1.243 os_linux.cpp

------- os_linux.cpp -------
*** /tmp/geta8042	Wed Nov 15 02:23:50 2006
--- /tmp/getb8042	Wed Nov 15 02:23:50 2006
***************
*** 3627,3633 ****
  }
  
  jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
!   return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
  }
  
  //
--- 3627,3637 ----
  }
  
  jlong os::current_thread_cpu_time(bool user_sys_cpu_time) {
!   if (user_sys_cpu_time && os::Linux::supports_fast_thread_cpu_time()) {
!     return os::Linux::fast_thread_cpu_time(CLOCK_THREAD_CPUTIME_ID);
!   } else {
!     return os::thread_cpu_time(Thread::current(), user_sys_cpu_time);
!   }
  }
  
  //

*** (#1 of 1): [ UNSAVED ] ###@###.###
                                     

EVALUATION

Fast thread CPU on Linux can be used when os::current_thread_cpu_time(bool user_sys_cpu_time) is called with user_sys_cpu_time == true.