From mboxrd@z Thu Jan  1 00:00:00 1970
From: Asias He <asias@redhat.com>
Subject: Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk
Date: Mon, 18 Jun 2012 16:03:23 +0800
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Cc: kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>,
	linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org,
	Christoph Hellwig <hch@lst.de>
To: Rusty Russell <rusty@rustcorp.com.au>
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On 06/18/2012 03:46 PM, Rusty Russell wrote:
> On Mon, 18 Jun 2012 14:53:10 +0800, Asias He <asias@redhat.com> wrote:
>> This patch introduces bio-based IO path for virtio-blk.
>
> Why make it optional?

request-based IO path is useful for users who do not want to bypass the 
IO scheduler in guest kernel, e.g. users using spinning disk. For users 
using fast disk device, e.g. SSD device, they can use bio-based IO path.

-- 
Asias