Subj : Re: architectures supported with nptl???
To   : comp.programming.threads
From : Randy
Date : Tue Jun 14 2005 06:53 pm

Joe Dupre wrote:
> I have seen mentioned in several places that CHOST or machine type must be
> i686 (or "higher"?) to have NPTL support enabled.  Is this true?
> 
> Am I wasting my time attemting to build in NPTL support for an i486 machine?
> I have not found anything clear on this subject.  (Then again, I  am not
> digging in the source code either).
> 
> -jmd

No, a 486 won't work.  According to Ulrich Drepper of Red Hat in 2002:
"
....
Everything before i686 lacks certain instructions which are necessary
for the current code.  Support for obsolete processors like i586
requires writing replacements for the missing files.  If nobody else
does it I'll do it sometime in the future but for now it is much more
important to support current, non-obsolete hardware.
"
https://listman.redhat.com/archives/phil-list/2002-November/msg00139.html

And according to Barry K. Nathan on Red Hat's RPM list in 2003:
"
....
Well, to the best of my knowledge, this is the NPTL situation:

(a) NPTL requires an x86 instruction that was added in the 486.
(b) As a result, glibc/NPTL has to be compiled for i486 or up.
(c) Red Hat compiles glibc for i386 and i686, but not i586.
(d) Therefore, Red Hat 9 only supports NPTL on i686 and up.
"
http://www.redhat.com/archives/rpm-list/2003-June/msg00068.html

So it sounds like it should be possible to put NPTL on a i586 (any
Pentium class machine), but not a 486.

For some background on the transition to NPTL:

  http://linuxdevices.com/articles/AT6753699732.html

For some in-depth up-to-date background on NPTL:

  http://people.redhat.com/drepper/nptl-design.pdf

    Randy

-- 
Randy Crawford   http://www.ruf.rice.edu/~rand   rand AT rice DOT edu

.