wow, cool.

   this is safer than the loaning-for-read()/write() stuff, since applications
   must explicitly ask for the new behaviour and the interface to do this is
   fairly standard already.  the interface is just a new open/fcntl flag,
   O_DIRECT, which is a hint that I/O done via this file descriptor be performed


WRT implementation, is this irix-alike or solaris-alike?  ie, for irix
it is a per-fd thing, but for solaris, it is a per-vnode thing (ie, 
turing on O_DIRECT for a file does it for all users, not just this fd.)


.mrg.