On Sun, 26 Sep 1999, Jason Thorpe wrote:

> Solaris has a B_ORDERED flag which is a hint specifically for this type
> of thing.
> 
> Basically, metadata writes (and any other writes that need to be ordered)
> would set B_ORDERED, and this would affect disksort() (for disks which
> don't supported tagged commands) and the type of tag used (for disks that do).
> 
> A B_URGENT (Head-Of-Queue tag) flag might also be useful.

I don't believe that any queue types other than simple queue are used,
primarily due to buggy implementations of other tag types in target
devices.  You must be thinking of some other OS.

=========================================================================
Eduardo Horvath				eeh@one-o.com
	"I need to find a pithy new quote." -- me