[ELDK] glibc change for eldk 3.1.1

[Detlev Zundel]

Hi Levend,

> What I know is just you said. Yes NPTL needs 2.6 series kernel. So I
> have a chance to use 4.2 ELDK.  But currently this is not applicable,
> since we are too near to release. Changing 2.4 kernel to 2.6 kernel
> would be huge impact right now.

Changing the thread library will also have a significant impact.

> So I did not see this as a applicable solution right now. And
> especially your paper about comparison of 2.4 and 2.6 kernels on ppc
> platforms made us to choose 2.4.
>
> But I have a RedHat 9.0 box. Its kernel is 2.4.20 and when you
>
> getconf GNU_LIBC_VERSION =>  glibc 2.3.2
> getconf GNU_LIBPTHREAD_VERSION =>  NPTL 0.29
>
> This configuration NPTL on 2.4 series gave me a hope.

A quick check on wikipedia would have quenched this hope[1]:

  NPTL has been part of Red Hat Enterprise Linux since version 3, and in
  the Linux kernel since version 2.6.

So NPTL in Linux 2.4 was a Red Hat only backport.  Such code certainly
is not in any of our 2.4 trees.

> I dowloaded 2.3.2 glibc. But I saw that no NPTL code is in its code
> base.  So I tried 2.3.3 glibc and I saw that NPTL 0.60 is in the code
> base. So I started to build it.
>
> I am using ELDK 3.1.1 toolchain. Configuration says ""thread-local
> storage not supported for this target".
>
> I read Ulrich Drepper's paper about TLS and checked ABI for
> powerpc. Nothing about tls on powerpc.
>
> But I think ELDK 4.2 has NPTL support on ppc. So how can it be
> possible ? Is this a hardware problem or software problem ?  Is TLS
> software emulated on powerpc ?

ELDK 4.2 needs a 2.6 kernel and the toolchain was built with NPTL
support.  Nothing more and nothing less.

Stepping back a little bit, what exact problem do you try to solve by
such desperate actions as switching to a new thread library very close
to release?

Cheers
  Detlev

[1] http://en.wikipedia.org/wiki/Native_POSIX_Thread_Library
 
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