diff options
| -rw-r--r-- | mm/memcontrol.c | 38 |
1 files changed, 31 insertions, 7 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a9318963d5d5..2bc3fbe93154 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -4763,6 +4763,33 @@ static void mem_cgroup_reparent_charges(struct mem_cgroup *memcg) } /* + * This mainly exists for tests during the setting of set of use_hierarchy. + * Since this is the very setting we are changing, the current hierarchy value + * is meaningless + */ +static inline bool __memcg_has_children(struct mem_cgroup *memcg) +{ + struct cgroup *pos; + + /* bounce at first found */ + cgroup_for_each_child(pos, memcg->css.cgroup) + return true; + return false; +} + +/* + * Must be called with cgroup_lock held, unless the cgroup is guaranteed to be + * already dead (in mem_cgroup_force_empty(), for instance). This is different + * from mem_cgroup_count_children(), in the sense that we don't really care how + * many children we have; we only need to know if we have any. It also counts + * any memcg without hierarchy as infertile. + */ +static inline bool memcg_has_children(struct mem_cgroup *memcg) +{ + return memcg->use_hierarchy && __memcg_has_children(memcg); +} + +/* * Reclaims as many pages from the given memcg as possible and moves * the rest to the parent. * @@ -4847,7 +4874,7 @@ static int mem_cgroup_hierarchy_write(struct cgroup *cont, struct cftype *cft, */ if ((!parent_memcg || !parent_memcg->use_hierarchy) && (val == 1 || val == 0)) { - if (list_empty(&cont->children)) + if (!__memcg_has_children(memcg)) memcg->use_hierarchy = val; else retval = -EBUSY; @@ -4964,8 +4991,7 @@ static int memcg_update_kmem_limit(struct cgroup *cont, u64 val) cgroup_lock(); mutex_lock(&set_limit_mutex); if (!memcg->kmem_account_flags && val != RESOURCE_MAX) { - if (cgroup_task_count(cont) || (memcg->use_hierarchy && - !list_empty(&cont->children))) { + if (cgroup_task_count(cont) || memcg_has_children(memcg)) { ret = -EBUSY; goto out; } @@ -5373,8 +5399,7 @@ static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft, cgroup_lock(); /* If under hierarchy, only empty-root can set this value */ - if ((parent->use_hierarchy) || - (memcg->use_hierarchy && !list_empty(&cgrp->children))) { + if ((parent->use_hierarchy) || memcg_has_children(memcg)) { cgroup_unlock(); return -EINVAL; } @@ -5709,8 +5734,7 @@ static int mem_cgroup_oom_control_write(struct cgroup *cgrp, cgroup_lock(); /* oom-kill-disable is a flag for subhierarchy. */ - if ((parent->use_hierarchy) || - (memcg->use_hierarchy && !list_empty(&cgrp->children))) { + if ((parent->use_hierarchy) || memcg_has_children(memcg)) { cgroup_unlock(); return -EINVAL; } |