pthreads in Linux

[Andreas Jaeger]

Kapish K <kapish@ureach.com> writes:

> Hello,
> 	Well, I looked at the code, and there are a few queries on
> this:
> Firstly, yes, sysdeps/i386/i686, there is a pt-machine.h, which
> includes useldt.h ( which has the #define for the register
> support ) and pt-machine.h is included in internals.h, which is
> included when linuxthreads is compiled.
> But, however, note that the useldt.h include in pt-machine.h
> itself is commented out with the following comment:
> /* Use the LDT implementation only if the kernel is fixed.  */
> //#include "../useldt.h"   

That's an old version of glibc you're looking it.

> Now I am confused.. What does this 'kernel is fixed' supposed to
> mean? Does this get included or not for i686 and why not for
> ix86 other than i686?
> Any pointers?

glibc 2.2.3 uses the LDT implementation if and only if you have a
working kernel (2.4.0 or newer, others had some serious bugs in LDT
handling) and work on i686 because older CPUs don't support all the
features we need.

Andreas
-- 
 Andreas Jaeger
  SuSE Labs aj@suse.de
   private aj@arthur.inka.de
    http://www.suse.de/~aj