Status of bio patches
---------------------

Functional and stable for IDE and SCSI, the various RAID controllers
(cpqarray, cciss, DAC960) have not been tested as I don't have the hw but
they should work too. The cciss/cpqarray maintainer is currently testing
cciss.

Highmem I/O should work on:

	- IDE (DMA of course, various PIO modes checked for correction
	  mapping and it seems good)
	- cpqarray and cciss (untested)
	- SCSI

SCSI support is currently enabled for aic7xxx and sym53c8xx. aic7xxx has
been tested a lot without problems. Same goes for IDE highmem. I'd be
surprised if there are any big show-stopper bugs left there.

ll_rw_kio works, and brw_kiovec was greatly simplified by this. No real
performance testing on this yet, just a simple dd for testing:

(clean kernel, 2.4.5-pre4)
bart:~ # time dd if=/dev/raw1 of=/dev/null bs=4k
128008+0 records in
128008+0 records out

real    0m43.130s
user    0m0.290s
sys     0m7.060s

(2.4.5-pre4 + bio)
bart:~ # time dd if=/dev/raw1 of=/dev/null bs=4k
128008+0 records in
128008+0 records out
real    0m38.478s
user    0m0.204s
sys     0m5.091s


Pending / TODO
--------------

- Convert more drivers that support I/O to higher memory pages to do so instead
  of using bounce buffers.
- Drop plug_tq and convert to per-queue unplugging.
- Merge my queue-barrier patch
- Look into moving more of the per-major arrays into the request_queue
- Fix md and lvm
- Fix ide-scsi
- Fix drivers/s390 block stuff
- Probably still some drivers that aren't converted and not listed, look

Feel free to jump in and start hacking on the TODO list :-)

Jens Axboe <axboe@suse.de>