From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx111.postini.com [74.125.245.111]) by kanga.kvack.org (Postfix) with SMTP id ED60F8D0001 for ; Mon, 8 Apr 2013 11:57:33 -0400 (EDT) Received: by mail-pa0-f47.google.com with SMTP id bj3so3331122pad.20 for ; Mon, 08 Apr 2013 08:57:33 -0700 (PDT) Date: Mon, 8 Apr 2013 08:57:26 -0700 From: Tejun Heo Subject: Re: [PATCH 1/8] cgroup: implement cgroup_is_ancestor() Message-ID: <20130408155726.GG3021@htj.dyndns.org> References: <51627DA9.7020507@huawei.com> <51627DBB.5050005@huawei.com> <20130408144750.GK17178@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130408144750.GK17178@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Li Zefan , Andrew Morton , Glauber Costa , KAMEZAWA Hiroyuki , Johannes Weiner , LKML , Cgroups , linux-mm@kvack.org Hello, On Mon, Apr 08, 2013 at 04:47:50PM +0200, Michal Hocko wrote: > On Mon 08-04-13 16:20:11, Li Zefan wrote: > [...] > > @@ -5299,6 +5300,26 @@ struct cgroup_subsys_state *cgroup_css_from_dir(struct file *f, int id) > > return css ? css : ERR_PTR(-ENOENT); > > } > > > > +/** > > + * cgroup_is_ancestor - test "root" cgroup is an ancestor of "child" > > + * @child: the cgroup to be tested. > > + * @root: the cgroup supposed to be an ancestor of the child. > > + * > > + * Returns true if "root" is an ancestor of "child" in its hierarchy. > > + */ > > +bool cgroup_is_ancestor(struct cgroup *child, struct cgroup *root) > > +{ > > + int depth = child->depth; > > Is this functionality helpful for other controllers but memcg? > css_is_ancestor is currently used only by memcg code AFAICS and we can > get the same functionality easily by using something like: It's a basic hierarchy operation. I'd prefer it to be in cgroup and in general let's try to avoid memcg-specific infrastructure. It doesn't seem to end well. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org