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

On Mon, 18 Jun 2012 16:03:23 +0800, Asias He [off-list ref] wrote:

On 06/18/2012 03:46 PM, Rusty Russell wrote:

quoted

On Mon, 18 Jun 2012 14:53:10 +0800, Asias He [off-list ref] wrote:

quoted

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.