Re: [Qemu-devel] [Qemu-discuss] iolimits for virtio-9p

[Pradeep Kiruvale]

On 26 April 2016 at 14:08, Alberto Garcia <address@hidden> wrote:

On Tue 19 Apr 2016 02:09:24 PM CEST, Pradeep Kiruvale wrote:

> We are planning to implement the io-limits for the virtio-9p driver
> i.e for fsdev devices.
> So, I am looking into the code base and how it has done for the block
> io devices.
>
> I would like to know how difficult is this and is there some one out
> there who has any plan to do this?

Hi,

as Stefan said already, the common API is in throttle.h.

It should be generic enough to be used in other parts of QEMU, but tell
me if you feel that it needs changes.

Once you configure the throttling settings you essentially only need to
call throttle_schedule_timer() to see if a request needs to be
throttled, and afterwards throttle_account() to register the I/O that
has been peformed.

You'll see that there's also throttle-group.c, but that's specific to
the block layer and not meant to be generic.

Hi Alberto,

Thanks for the reply. I am still in the early phase, I will let you know

if any changes are needed for the APIs. 

We might also have to implement throttle-group.c for 9p devices, if we want to

apply throttle for group of devices.

I just want some one from virtio-9p side to jump in to the discussion 

as well. That will help me a lot to understand from virtio-9p perspective.

Regards,

Pradeep