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From: Anthony Liguori <anthony@codemonkey.ws>
Date: Tue, 25 Jul 2006 09:55:14 -0500
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Subject: [Qemu-devel] Re: high CPU load / async IO?
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To: qemu-devel@nongnu.org

On Tue, 25 Jul 2006 00:51:23 +0200, Sven Köhler wrote:

>> IDE only supports one outstanding request, so having a thread that runs
>> the synchronous block routines appears reasonable.  However, SATA and SCSI
>> both support multiple outstanding requests.  The extension to the existing
>> patch would be simple--increase the number of threads.
> 
> ???
> 
> Wasn't there another variant using the async-I/O support of the Host OS
> and thereby supporting a larger number of outstanding requests?

Not that I know of.  Do you have a pointer?

> The approch that i mentioned above (using the host's async I/O) is what
> you mean with using linux-aio, right?

It depends on what you mean by the host's async I/O implementation.

>> So the current thread-based async dma patch is really just the wrong long
>> term solution.  A more long term solution is likely in the works.  It
>> requires quite a bit of code modification though.
> 
> I see. So in other words:
> 
> don't ask for simple async I/O now. The more complex and flexible
> sollution will follow soon.

Yes, hopefully really soon.

Regards,

Anthony Liguori

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