Re: [PATCH V3 11/12] blktrace: add an option to allow displying cgroup path

[Tejun Heo <tj@kernel.org>]

Hello,

On Thu, Jun 15, 2017 at 11:17:19AM -0700, Shaohua Li wrote:
> From: Shaohua Li <shli@fb.com>
> 
> By default we output cgroup id in blktrace. This adds an option to
> display cgroup path. Since get cgroup path is a relativly heavy
> operation, we don't enable it by default.
> 
> with the option enabled, blktrace will output something like this:
> dd-1353  [007] d..2   293.015252:   8,0   /test/level  D   R 24 + 8 [dd]
> 
> Signed-off-by: Shaohua Li <shli@fb.com>
> @@ -613,6 +613,9 @@ static inline struct kernfs_node_id *cgroup_get_node_id(struct cgroup *cgrp)
>  {
>  	return &cgrp->kn->id;
>  }
> +
> +void cgroup_path_from_node_id(const struct kernfs_node_id *id,
> +					char *buf, size_t buflen);

Maybe cgroup_path_from_kernfs_id()?  We eventually can replace
cgrp->id w/ kernfs id and drop the kernfs qualifier.

Thanks.

-- 
tejun