Re: [PATCH] move xchg/cmpxchg to atomic.h

[Alan Cox]

> > We really can't.  We _only_ have load-and-zero.  And it has to be 16-byte
> > aligned.  xchg() is just not something the CPU implements.
> 
> The network code relies on the reader-xchg semantics David described in 
> several places.

I guess the network code will just have to change for 2.5. read_xchg_val()
can be a null macro for everyone else at least