On Fri, Dec 14, 2007 at 11:08:04AM +0000, Chris Gilbert wrote:
> [...]
> Note that -current kernels seem to hang when unmounting the fs.  This
> is a seperate issue, and appears to be because interrupts need to be
> enabled to unmount filesystems.

that's true; and it also needs scheduling. Almost all disk subsystems
(raidframe, ata, atapi, scsi, usb, ...) use kernel threads for
non-polled transfers.

-- 
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
     NetBSD: 26 ans d'experience feront toujours la difference
--