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Date: Thu, 11 Sep 2008 09:04:16 -0500
From: Anthony Liguori <aliguori@us.ibm.com>
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Subject: [Qemu-devel] Re: [PATCH][RFC] Refactor AIO to allow multiple AIO
	implementations
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To: Gerd Hoffmann <kraxel@redhat.com>
Cc: Ryan Harper <ryanh@us.ibm.com>, qemu-devel@nongnu.org, kvm@vger.kernel.org

Gerd Hoffmann wrote:
> Anthony Liguori wrote:
>   
>> Gerd Hoffmann wrote:
>>     
>>> Hmm, what is the long-term plan for this?
>>>       
>> Step one is to move the generic aio bits out of block-raw-posix (which
>> this patch does).
>>
>> Step two is to move the posix-aio routines out of block-raw-posix.
>>
>> Step three would be to add a generic interface to allow block-raw-posix
>> to use multiple aio implementations
>>
>> Step four would be to add a new aio implementation
>>     
>
> Sounds good.
>
>   
>> (I think the best
>> route is a thread-pool based implementation).
>>     
>
> Not sure about that.  linux-aio would have the advantage that the kernel
> knows about all the requests in flight and probably can do a better job
> on I/O ordering and scheduling then.  But once we can have multiple
> different implementations we can just try ;)
>   

But linux-aio doesn't work unless you're using O_DIRECT so for a lot of 
users, it's not very helpful.

Regards,

Anthony Liguori

> cheers,
>   Gerd
>
>