diff options
| -rw-r--r-- | kernel/cpuset.c | 85 |
1 files changed, 54 insertions, 31 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index e857887bd246..4b054b9faf3d 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -200,6 +200,19 @@ static struct cpuset top_cpuset = { (1 << CS_MEM_EXCLUSIVE)), }; +/** + * cpuset_for_each_child - traverse online children of a cpuset + * @child_cs: loop cursor pointing to the current child + * @pos_cgrp: used for iteration + * @parent_cs: target cpuset to walk children of + * + * Walk @child_cs through the online children of @parent_cs. Must be used + * with RCU read locked. + */ +#define cpuset_for_each_child(child_cs, pos_cgrp, parent_cs) \ + cgroup_for_each_child((pos_cgrp), (parent_cs)->css.cgroup) \ + if (is_cpuset_online(((child_cs) = cgroup_cs((pos_cgrp))))) + /* * There are two global mutexes guarding cpuset structures. The first * is the main control groups cgroup_mutex, accessed via @@ -419,48 +432,55 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial) { struct cgroup *cont; struct cpuset *c, *par; + int ret; + + rcu_read_lock(); /* Each of our child cpusets must be a subset of us */ - list_for_each_entry(cont, &cur->css.cgroup->children, sibling) { - if (!is_cpuset_subset(cgroup_cs(cont), trial)) - return -EBUSY; - } + ret = -EBUSY; + cpuset_for_each_child(c, cont, cur) + if (!is_cpuset_subset(c, trial)) + goto out; /* Remaining checks don't apply to root cpuset */ + ret = 0; if (cur == &top_cpuset) - return 0; + goto out; par = cur->parent; /* We must be a subset of our parent cpuset */ + ret = -EACCES; if (!is_cpuset_subset(trial, par)) - return -EACCES; + goto out; /* * If either I or some sibling (!= me) is exclusive, we can't * overlap */ - list_for_each_entry(cont, &par->css.cgroup->children, sibling) { - c = cgroup_cs(cont); + ret = -EINVAL; + cpuset_for_each_child(c, cont, par) { if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && c != cur && cpumask_intersects(trial->cpus_allowed, c->cpus_allowed)) - return -EINVAL; + goto out; if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) && c != cur && nodes_intersects(trial->mems_allowed, c->mems_allowed)) - return -EINVAL; + goto out; } /* Cpusets with tasks can't have empty cpus_allowed or mems_allowed */ - if (cgroup_task_count(cur->css.cgroup)) { - if (cpumask_empty(trial->cpus_allowed) || - nodes_empty(trial->mems_allowed)) { - return -ENOSPC; - } - } + ret = -ENOSPC; + if (cgroup_task_count(cur->css.cgroup) && + (cpumask_empty(trial->cpus_allowed) || + nodes_empty(trial->mems_allowed))) + goto out; - return 0; + ret = 0; +out: + rcu_read_unlock(); + return ret; } #ifdef CONFIG_SMP @@ -501,10 +521,10 @@ update_domain_attr_tree(struct sched_domain_attr *dattr, struct cpuset *c) if (is_sched_load_balance(cp)) update_domain_attr(dattr, cp); - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); + rcu_read_lock(); + cpuset_for_each_child(child, cont, cp) list_add_tail(&child->stack_list, &q); - } + rcu_read_unlock(); } } @@ -623,10 +643,10 @@ static int generate_sched_domains(cpumask_var_t **domains, continue; } - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); + rcu_read_lock(); + cpuset_for_each_child(child, cont, cp) list_add_tail(&child->stack_list, &q); - } + rcu_read_unlock(); } for (i = 0; i < csn; i++) @@ -1824,7 +1844,8 @@ static int cpuset_css_online(struct cgroup *cgrp) { struct cpuset *cs = cgroup_cs(cgrp); struct cpuset *parent = cs->parent; - struct cgroup *tmp_cg; + struct cpuset *tmp_cs; + struct cgroup *pos_cg; if (!parent) return 0; @@ -1853,12 +1874,14 @@ static int cpuset_css_online(struct cgroup *cgrp) * changed to grant parent->cpus_allowed-sibling_cpus_exclusive * (and likewise for mems) to the new cgroup. */ - list_for_each_entry(tmp_cg, &cgrp->parent->children, sibling) { - struct cpuset *tmp_cs = cgroup_cs(tmp_cg); - - if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) + rcu_read_lock(); + cpuset_for_each_child(tmp_cs, pos_cg, parent) { + if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs)) { + rcu_read_unlock(); return 0; + } } + rcu_read_unlock(); mutex_lock(&callback_mutex); cs->mems_allowed = parent->mems_allowed; @@ -2027,10 +2050,10 @@ static struct cpuset *cpuset_next(struct list_head *queue) cp = list_first_entry(queue, struct cpuset, stack_list); list_del(queue->next); - list_for_each_entry(cont, &cp->css.cgroup->children, sibling) { - child = cgroup_cs(cont); + rcu_read_lock(); + cpuset_for_each_child(child, cont, cp) list_add_tail(&child->stack_list, queue); - } + rcu_read_unlock(); return cp; } |