Messages in this thread | | | Date | Fri, 9 Nov 2012 17:13:01 +0800 | From | Li Zefan <> | Subject | Re: [PATCH 3/9 v2] cgroup: implement generic child / descendant walk macros |
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On 2012/11/9 1:59, Tejun Heo wrote: > Currently, cgroup doesn't provide any generic helper for walking a > given cgroup's children or descendants. This patch adds the following > three macros. > > * cgroup_for_each_child() - walk immediate children of a cgroup. > > * cgroup_for_each_descendant_pre() - visit all descendants of a cgroup > in pre-order tree traversal. > > * cgroup_for_each_descendant_post() - visit all descendants of a > cgroup in post-order tree traversal. > > All three only require the user to hold RCU read lock during > traversal. Verifying that each iterated cgroup is online is the > responsibility of the user. When used with proper synchronization, > cgroup_for_each_descendant_pre() can be used to propagate state > updates to descendants in reliable way. See comments for details. > > v2: s/config/state/ in commit message and comments per Michal. More > documentation on synchronization rules. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujisu.com> > Reviewed-by: Michal Hocko <mhocko@suse.cz>
I don't see anything wrong with the comment on cgroup_next_descendant_pre().
Acked-by: Li Zefan <lizefan@huawei.com>
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