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From: "Sven Köhler" <skoehler@upb.de>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: qemu (cvs-version) performance?
Date: Sat, 11 Mar 2006 23:35:48 +0100	[thread overview]
Message-ID: <duvjc7$d7$1@sea.gmane.org> (raw)
In-Reply-To: <200603112225.16535.paul@codesourcery.com>

>> I thought, that qemu-0.8.0's problem would be disk-IO. I installed
>> Windows 2000 and in the task-manager the CPU-Time is 100% during intense
>> IO. A "dir c:\ /A /S /B >NUL:" on the console causes 100% CPU-time and
>> most of it being that red-colored "in-kernel-time".
> 
> Qemu host IO is syncrhonous. ie. the guest is paused on the instruction that 
> issues the IO until the IO completes. As for as the guest is concerned it 
> happens instantly. This is all your test shows.

I have seen thoughts about asynchronous IO for qemu. I thought that they
would have been integrated along with the DMA-patches already.

I would really see how qemu performs with asynch IO enabled. Are there
any patches out there?


Greetings
  Sven

  reply	other threads:[~2006-03-11 22:36 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-03-11  3:34 [Qemu-devel] qemu (cvs-version) performance? Sven Köhler
2006-03-11 22:25 ` Paul Brook
2006-03-11 22:35   ` Sven Köhler [this message]
2006-03-11 22:58     ` [Qemu-devel] " Sven Köhler
2006-03-11 23:01     ` Jim C. Brown

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