Messages in this thread | | | Date | Mon, 17 Dec 2012 13:15:17 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH 06/12] cfq-iosched: implement cfq_group->nr_active and ->level_weight |
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Hello, Vivek.
On Mon, Dec 17, 2012 at 03:46:09PM -0500, Vivek Goyal wrote: > On Fri, Dec 14, 2012 at 02:41:19PM -0800, Tejun Heo wrote: > > To prepare for blkcg hierarchy support, add cfqg->nr_active and > > ->level_weight. cfqg->nr_active counts the number of active cfqgs at > > the cfqg's level and ->level_weight is sum of weights of those cfqgs. > > The level covers itself (cfqg->leaf_weight) and immediate children. > > This notion of level is really confusing. If one says "at cfqg's level" > I immediately associate with cfqg's siblings and not with cfqg's children.
We can explicitly say at children's level but I think it should be enough to explain it clearly in the comment where the field is defined.
> I think confusion happens because we are overloading the definition of > cfqg. It is competing with its siblings at the same time it is competing > against its child groups (on behalf of its children tasks).
While I agree that part is a bit tricky, I can't think of a much better way to describe it. Any better ideas?
Thanks.
-- tejun
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