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Date: Wed, 26 Jul 2006 19:54:44 +0200
From: Jens Axboe <qemu@kernel.dk>
Subject: Re: [Qemu-devel] Re: high CPU load / async IO?
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To: qemu-devel@nongnu.org

On Wed, Jul 26 2006, Sven K=F6hler wrote:
> >>>>> Sounds good, so at least it's on its way :-)
> >>>>> It's on of those big items left on the TODO, so will be good to s=
ee go
> >>>>> in. Then one should implement an ahci host controller for queued
> >>>>> command support next...
> >>>> Or use the scsi emulation :-)
> >>> Ah, did not know that queueing was fully implemented there yet!
> >> It isn't, but it's nearer than the SATA emulation!
> >=20
> > ahci wouldn't be too much work, but definitely more so than finishing
> > the scsi bits!
>=20
> That sounds great! I feel, like my dreams come true.
>=20
>=20
> BTW: Fabrice said, he will use the POSIX AIO (i guess, he means
> http://www.bullopensource.org/posix/ in case of Linux, right?)

Well I would assume that he just would use the glibc posix aio, which is
suboptimal but at least the code can be reused. The bull project looks
like it's trying to mimic posix aio on top of linux aio, so (if they got
the details right) that should be faster. I didn't check their sources,
though. You should be able to use the bull stuff with qemu, it would
most likely overloading the glibc function for posix aio.

> Which other OS do also support the POSIX AIO API?

No idea really, but I would guess any "unixy" OS out there.

--=20
Jens Axboe