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Date: Thu, 1 May 2008 17:35:51 +0300
From: "Blue Swirl" <blauwirbel@gmail.com>
Subject: Re: [Qemu-devel] [PATCH] Align file accesses with cache=off (O_DIRECT)
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To: Kevin Wolf <mail@kevin-wolf.de>
Cc: Laurent Vivier <Laurent.Vivier@bull.net>, qemu-devel@nongnu.org

On 5/1/08, Kevin Wolf <mail@kevin-wolf.de> wrote:
> Am Mittwoch, 30. April 2008 16:30:27 schrieb Blue Swirl:
>
> > Maybe the alignment could be handled like AIO and synchronous IO
>  > emulation layers are added in bdrv_register, but at open stage?
>
>
> You mean to preserve the original pread if the file is opened without O_DIRECT
>  and replace it by the emulation function only if O_DIRECT is really used?

Right.

>  Certainly possible in some way (having a function pointer in BDRVRawState),
>  but this won't save us anything.
>
>  But maybe I'm just missing your point. How exactly do you want to handle
>  things and what does it improve?

Maybe it's slightly faster that way and it would be closer to how
other block emulations are handled. It's just an idea.