Re: [PATCH 02/13] block: introduce bio_issue_as_root_blkg

From: Tejun Heo
Date: Wed May 30 2018 - 11:53:27 EST


On Tue, May 29, 2018 at 05:17:13PM -0400, Josef Bacik wrote:
> From: Josef Bacik <jbacik@xxxxxx>
>
> Instead of forcing all file systems to get the right context on their
> bio's, simply check for REQ_META to see if we need to issue as the root
> blkg. We don't want to force all bio's to have the root blkg associated
> with them if REQ_META is set, as some controllers (blk-iolatency) need
> to know who the originating cgroup is so it can backcharge them for the
> work they are doing. This helper will make sure that the controllers do
> the proper thing wrt the IO priority and backcharging.
>
> Signed-off-by: Josef Bacik <jbacik@xxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks.

--
tejun