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@xxxxxxxxxx> > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxx> > Reviewed-by: Michal Hocko <mhocko@xxxxxxx> I don't see anything wrong with the comment on cgroup_next_descendant_pre(). Acked-by: Li Zefan <lizefan@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
