QEMU AIO patch

[Sean C. Farley]

Awhile ago, I wrote a patch to take advantage of FreeBSD's
aio_waitcomplete() call in the QEMU raw block code.  It took some doing,
but I finally found a copy of the patch[1] on a laptop that started
dying about a year ago.

Using aio_waitcomplete() should reduce the number of context switches
present in the current code.  I have not truly tested the patch to see
how well it helps.  Since it is FreeBSD-only, I am posting it here
instead of directly to the QEMU mailing list.

Sean
   1. http://www.farley.org/freebsd/tmp/qemu-aio.patch
-- 
scf at FreeBSD.org