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Date: Fri, 19 Nov 2010 19:39:02 +0100
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] [PATCH 12/16] scsi-generic: use plain ioctl
Message-ID: <20101119183901.GI32461@lst.de>
References: <20101118144736.C183DF90AB@ochil.suse.de>
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To: Hannes Reinecke <hare@suse.de>
Cc: stefanha@gmail.com, qemu-devel@nongnu.org, nab@linux-iscsi.org, kraxel@redhat.com

On Thu, Nov 18, 2010 at 03:47:36PM +0100, Hannes Reinecke wrote:
> 
> aio_ioctl is emulated anyway and currently broken.

What's broken about it currently?

> So better use 'normal' ioctl here as there are no benefits
> on using the emulated async I/O call.

There are huge benefits.  Without it the whole scsi command execution
happens synchronously in the qemu main loop, blocking guest execution.