Just curious

[utzoo!decvax!duke!chico!harpo!utah-cs!utah-gr!thomas]

In indone, at least, the code is running at interrupt level - iodone
is usually called from the interrupt service routine, thus it is already
spl'ed.  The reason for running the test at spl6 is so nobody sneaks in
and sets the B_WANTED flag after you've looked, but before you've cleared
the B_BUSY (or whatever) further down.  If nobody sets B_WANTED at interrupt
level, then the spl's are superfluous.
=S