Using __kuser_cmpxchg

[Andrew Haley]

David Daney writes:
 > Andrew Haley wrote:
 > > David Daney writes:
 > >  > 
 > >  > Am I missing something here?
 > >  > 
 > >  > Is it really impossible to implement compare_and_swap on these ARM 
 > >  > platforms?
 > > 
 > > No, but it is exceedingly difficult to do it *efficiently*.
 > > 
 > 
 > Right, I think you told me that once before.
 > 
 > I forget, is the arm-linuxeabi port of libgcj currently sacrificing 
 > correctness for speed?

Yeah, that's right, and it's what I'm trying to fix.  Unfortunately,
the suggested cure seems to be worse than the disease.

Andrew.