Re: [Qemu-devel] [PATCH v8 3/4] block: add block timer and throttling algorithm

[Marcelo Tosatti]

On Thu, Sep 08, 2011 at 06:11:07PM +0800, Zhi Yong Wu wrote:
> Note:
>      1.) When bps/iops limits are specified to a small value such as 511 
> bytes/s, this VM will hang up. We are considering how to handle this senario.

You can increase the length of the slice, if the request is larger than
slice_time * bps_limit.

>      2.) When "dd" command is issued in guest, if its option bs is set to a 
> large value such as "bs=1024K", the result speed will slightly bigger than 
> the limits.

Why?

There is lots of debugging leftovers in the patch.