>> - Maybe the uio doesn't know what address space it's for.

> It knows what address space it belongs to, but [...].
> It *could* be changed to use uvm_io(), but uvm_io() requires a fair
> bit of TLB frobbing and consumes KVA space, so it may be more
> overhead to use uvm_io() in some situations.

Perhaps it would be interesting to try uvm_io versus copying through a
kernel buffer and see how it affects performance for various I/O sizes
(and on various machines - I'm sure uvm_io is more expensive on some
architectures than others!).

I've got eight ports running at home; I may try this if nobody does it
first (and if I can figure out enough of uvm).  (Only six
architectures, though, since three of the ports are 68k - mac68k,
next68k, and sun3; the others are sparc, alpha, vax, i386, macppc.)

					der Mouse

			       mouse@rodents.montreal.qc.ca
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