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Description of problem:
There may be a condition where nptl and the 2.6 kernel are causing
problems.

I use the SLIME package under GNU emacs to work with lisp.  I am using
SBCL as my preferred lisp package.  SBCL has been compiled with nptl
enabled.

This package worked under FC1 and the 2.4 kernel.  However, taking my
same .emacs file and running under FC2 causes the system to lock up
during the initialization of the SWANK portion of SLIME.  There is
also some discussion on this topic under comp.lang.lisp, where the
general consensus is that it is the use of nptl in SBCL and the 2.6
kernel that is causing the problem.

I have duplicated this problem on two different hosts.  One of those
hosts acts as a gateway for my home network.  When the lock up
happened, I was unable to get any response from the keyboard, mouse,
or even by trying to ssh to the box.  Interestingly enough though, the
box continued to act as a gateway even though all other processing
appeared to be dead so the entire kernel is not locked up.

Version-Release number of selected component (if applicable):
kernel-2.6.5-1.358

How reproducible:
Always

Steps to Reproduce:
1.Add the SLIME package to your local elisp directory
(http://common-lisp.net/project/slime/)
2.Install SBCL (SBCL 0.8.10 is what I'm using with nptl)
3.From emacs start slime (M-x slime) 
    

Actual Results:  The inferior lisp starts up and you see some status
messages scroll by and then the system locks up hard.

Expected Results:  Under FC1, it starts up perfectly.

Additional info: