Re: [RFC 1/2] block: record blkcss in request

[Tejun Heo]

On Wed, Oct 04, 2017 at 11:02:46AM -0700, Shaohua Li wrote:
> > Each request comes from cgroup specific request_list, so given a
> > request, its blkcg membership can is accessible through
> > 
> > request->rl->blkg->blkcg
> 
> Nice. Seems only used for legacy queue though.

Ah, you're right.  rl isn't used for mq at all, so yeah, we probably
should propagate the association through rq.

Thanks.

-- 
tejun

Re: [RFC 1/2] block: record blkcss in request

[Shaohua Li]

On Wed, Oct 04, 2017 at 10:51:49AM -0700, Tejun Heo wrote:
> Hello, Shaohua.
> 
> On Wed, Oct 04, 2017 at 10:41:19AM -0700, Shaohua Li wrote:
> > From: Shaohua Li 
> > 
> > Currently we record block css info in bio but not in request. Normally
> > we can get a request's css from its bio, but in some situations, we
> > can't access request's bio, for example, after blk_update_request. Add
> > the css to request, so we can access css through the life cycle of a
> > request.
> 
> Each request comes from cgroup specific request_list, so given a
> request, its blkcg membership can is accessible through
> 
>   request->rl->blkg->blkcg

Nice. Seems only used for legacy queue though.

Thanks,
Shaohua

Re: [RFC 1/2] block: record blkcss in request

[Tejun Heo]

Hello, Shaohua.

On Wed, Oct 04, 2017 at 10:41:19AM -0700, Shaohua Li wrote:
> From: Shaohua Li 
> 
> Currently we record block css info in bio but not in request. Normally
> we can get a request's css from its bio, but in some situations, we
> can't access request's bio, for example, after blk_update_request. Add
> the css to request, so we can access css through the life cycle of a
> request.

Each request comes from cgroup specific request_list, so given a
request, its blkcg membership can is accessible through

request->rl->blkg->blkcg

Thanks.

-- 
tejun