diff options
Diffstat (limited to 'include/linux/cgroup.h')
| -rw-r--r-- | include/linux/cgroup.h | 88 |
1 files changed, 46 insertions, 42 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index c288bce428f8..4bc22f4a1abb 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -779,68 +779,72 @@ static inline struct cgroup *cgroup_from_id(struct cgroup_subsys *ss, int id) return idr_find(&ss->root->cgroup_idr, id); } -struct cgroup *cgroup_next_child(struct cgroup *pos, struct cgroup *cgrp); +struct cgroup_subsys_state *css_next_child(struct cgroup_subsys_state *pos, + struct cgroup_subsys_state *parent); /** - * cgroup_for_each_child - iterate through children of a cgroup - * @pos: the cgroup * to use as the loop cursor - * @cgrp: cgroup whose children to walk + * css_for_each_child - iterate through children of a css + * @pos: the css * to use as the loop cursor + * @parent: css whose children to walk * - * Walk @cgrp's children. Must be called under rcu_read_lock(). A child - * cgroup which hasn't finished ->css_online() or already has finished + * Walk @parent's children. Must be called under rcu_read_lock(). A child + * css which hasn't finished ->css_online() or already has finished * ->css_offline() may show up during traversal and it's each subsystem's * responsibility to verify that each @pos is alive. * * If a subsystem synchronizes against the parent in its ->css_online() and - * before starting iterating, a cgroup which finished ->css_online() is + * before starting iterating, a css which finished ->css_online() is * guaranteed to be visible in the future iterations. * * It is allowed to temporarily drop RCU read lock during iteration. The * caller is responsible for ensuring that @pos remains accessible until * the start of the next iteration by, for example, bumping the css refcnt. */ -#define cgroup_for_each_child(pos, cgrp) \ - for ((pos) = cgroup_next_child(NULL, (cgrp)); (pos); \ - (pos) = cgroup_next_child((pos), (cgrp))) +#define css_for_each_child(pos, parent) \ + for ((pos) = css_next_child(NULL, (parent)); (pos); \ + (pos) = css_next_child((pos), (parent))) -struct cgroup *cgroup_next_descendant_pre(struct cgroup *pos, - struct cgroup *cgroup); -struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos); +struct cgroup_subsys_state * +css_next_descendant_pre(struct cgroup_subsys_state *pos, + struct cgroup_subsys_state *css); + +struct cgroup_subsys_state * +css_rightmost_descendant(struct cgroup_subsys_state *pos); /** - * cgroup_for_each_descendant_pre - pre-order walk of a cgroup's descendants - * @pos: the cgroup * to use as the loop cursor - * @cgroup: cgroup whose descendants to walk + * css_for_each_descendant_pre - pre-order walk of a css's descendants + * @pos: the css * to use as the loop cursor + * @root: css whose descendants to walk * - * Walk @cgroup's descendants. Must be called under rcu_read_lock(). A - * descendant cgroup which hasn't finished ->css_online() or already has + * Walk @root's descendants. Must be called under rcu_read_lock(). A + * descendant css which hasn't finished ->css_online() or already has * finished ->css_offline() may show up during traversal and it's each * subsystem's responsibility to verify that each @pos is alive. * * If a subsystem synchronizes against the parent in its ->css_online() and * before starting iterating, and synchronizes against @pos on each - * iteration, any descendant cgroup which finished ->css_online() is + * iteration, any descendant css which finished ->css_online() is * guaranteed to be visible in the future iterations. * * In other words, the following guarantees that a descendant can't escape * state updates of its ancestors. * - * my_online(@cgrp) + * my_online(@css) * { - * Lock @cgrp->parent and @cgrp; - * Inherit state from @cgrp->parent; + * Lock @css's parent and @css; + * Inherit state from the parent; * Unlock both. * } * - * my_update_state(@cgrp) + * my_update_state(@css) * { - * Lock @cgrp; - * Update @cgrp's state; - * Unlock @cgrp; + * Lock @css; + * Update @css's state; + * Unlock @css; * - * cgroup_for_each_descendant_pre(@pos, @cgrp) { + * css_for_each_descendant_pre(@pos, @css) { * Lock @pos; - * Verify @pos is alive and inherit state from @pos->parent; + * Verify @pos is alive and inherit state from @pos's parent; * Unlock @pos; * } * } @@ -851,8 +855,7 @@ struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos); * visible by walking order and, as long as inheriting operations to the * same @pos are atomic to each other, multiple updates racing each other * still result in the correct state. It's guaranateed that at least one - * inheritance happens for any cgroup after the latest update to its - * parent. + * inheritance happens for any css after the latest update to its parent. * * If checking parent's state requires locking the parent, each inheriting * iteration should lock and unlock both @pos->parent and @pos. @@ -865,25 +868,26 @@ struct cgroup *cgroup_rightmost_descendant(struct cgroup *pos); * caller is responsible for ensuring that @pos remains accessible until * the start of the next iteration by, for example, bumping the css refcnt. */ -#define cgroup_for_each_descendant_pre(pos, cgroup) \ - for (pos = cgroup_next_descendant_pre(NULL, (cgroup)); (pos); \ - pos = cgroup_next_descendant_pre((pos), (cgroup))) +#define css_for_each_descendant_pre(pos, css) \ + for ((pos) = css_next_descendant_pre(NULL, (css)); (pos); \ + (pos) = css_next_descendant_pre((pos), (css))) -struct cgroup *cgroup_next_descendant_post(struct cgroup *pos, - struct cgroup *cgroup); +struct cgroup_subsys_state * +css_next_descendant_post(struct cgroup_subsys_state *pos, + struct cgroup_subsys_state *css); /** - * cgroup_for_each_descendant_post - post-order walk of a cgroup's descendants - * @pos: the cgroup * to use as the loop cursor - * @cgroup: cgroup whose descendants to walk + * css_for_each_descendant_post - post-order walk of a css's descendants + * @pos: the css * to use as the loop cursor + * @css: css whose descendants to walk * - * Similar to cgroup_for_each_descendant_pre() but performs post-order + * Similar to css_for_each_descendant_pre() but performs post-order * traversal instead. Note that the walk visibility guarantee described in * pre-order walk doesn't apply the same to post-order walks. */ -#define cgroup_for_each_descendant_post(pos, cgroup) \ - for (pos = cgroup_next_descendant_post(NULL, (cgroup)); (pos); \ - pos = cgroup_next_descendant_post((pos), (cgroup))) +#define css_for_each_descendant_post(pos, css) \ + for ((pos) = css_next_descendant_post(NULL, (css)); (pos); \ + (pos) = css_next_descendant_post((pos), (css))) /* A cgroup_iter should be treated as an opaque object */ struct cgroup_iter { |