Re: [PATCH 3/3] virtio-blk: Add bio-based IO path for virtio-blk

[Rusty Russell]

On Mon, 18 Jun 2012 16:03:23 +0800, Asias He <asias@xxxxxxxxxx> wrote:
> On 06/18/2012 03:46 PM, Rusty Russell wrote:
> > On Mon, 18 Jun 2012 14:53:10 +0800, Asias He <asias@xxxxxxxxxx> 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.

Users using a spinning disk still get IO scheduling in the host though.
What benefit is there in doing it in the guest as well?

Cheers,
Rusty.
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