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Date: Mon, 13 Jun 2011 13:13:06 +0400
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From: Dmitry Konishchev <konishchev@gmail.com>
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Subject: Re: [Qemu-devel] [PATCH] CPU consumption optimization of 'qemu-img
 convert' using bdrv_is_allocated()
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To: Stefan Hajnoczi <stefanha@gmail.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org

On Mon, Jun 13, 2011 at 12:26 PM, Stefan Hajnoczi <stefanha@gmail.com> wrot=
e:
> The optimization is to check allocation metadata instead of
> unconditionally reading and then checking for all zeroes?
Yeah, exactly.

On Mon, Jun 13, 2011 at 12:26 PM, Stefan Hajnoczi <stefanha@gmail.com> wrot=
e:
> Why introduce a new constant instead of using BDRV_SECTOR_SIZE?
OK, I'll fix this.

On Mon, Jun 13, 2011 at 12:26 PM, Stefan Hajnoczi <stefanha@gmail.com> wrot=
e:
> "iff" is not a typo. =A0It means "if and only if".
Sorry, I don't know English so good. :) Will revert this.

On Mon, Jun 13, 2011 at 12:26 PM, Stefan Hajnoczi <stefanha@gmail.com> wrot=
e:
> I think the recursive is_allocated() needs its own function. =A0This
> function is already long/complex enough :).
I haven't done this because in this case I have to pass too lot of
local variables to this function. Just not sure that it'll look
better. But if you mind I surely can do this.

--=20
Dmitry Konishchev
mailto:konishchev@gmail.com