[erlang-questions] is Linux's clock_gettime still "not stable" enough for Erlang?

[mats cronqvist]

Adam Kocoloski <adam.kocoloski@REDACTED> writes:

> Hi, it seems to me that cpu_timestamp tracing is automatically  
> disabled on Linux.  configure spits out
>
>> checking if clock_gettime can be used to get process CPU time... not  
>> stable, disabled
>
> and in aclocal.m4 I see
>
>> case $host_os in
>> 	linux*)
>> 		AC_MSG_RESULT([not stable, disabled])
>> 		LIBRT=$xrtlib
>> 		;;
>> 	*)
>
> I'm wondering what the rationale was behind that, and in particular  
> whether newer kernels might have fixed the problem.  Does anyone  
> around here know a little more of the backstory? Best,

  I'm not really familiar with this, so the following is at best partly
  right.

  configure checks for a syscall;
http://www.linuxhowtos.org/manpages/2/clock_gettime.htm

  On linuxen, this needs support from hardware, the kernel and libc.

  E.g. on debian, with a 2.6 kernel, on i686 HW, you need to install
  libc6-i686. That will give you a variant of clock_gettime that is
  deemed "stable" by configure.

  mats