> | eeh@netbsd.org writes:
> | > Given that this is supposed to reduce confusion, I'd prefer to lop
> | > off some of the letters at the front rather than the part with 
> | > real significance.  Is BUS_SPACE_BARRIER_W_R obvious as to what
> | > it does?
> |
> | Uh, is "BUS_SPACE_BARRIER_WRITE_READ" obvious as to what it does?!
> 
> In my experience it's more difficult to immediately detect the
> difference between BUS_SPACE_BARRIER_WRITE_READ and
> BUS_SPACE_BARRIER_READ_WRITE than BUS_SPACE_BARRIER_W_R
> and BUS_SPACE_BARRIER_R_W, which is likely to result in
> fewere typos.

The thing I think is least obvious about either of these is wheter the 
sequences are X before Y or X after Y; why not

..._RAW
..._RAR
..._WAR
..._WAW

Or a B if that is what it really means?

R.