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-rw-r--r--kernel/cgroup/cpuset.c77
1 files changed, 58 insertions, 19 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index dc653ab26e50..5de18448016c 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -591,6 +591,35 @@ static inline void free_cpuset(struct cpuset *cs)
}
/*
+ * validate_change_legacy() - Validate conditions specific to legacy (v1)
+ * behavior.
+ */
+static int validate_change_legacy(struct cpuset *cur, struct cpuset *trial)
+{
+ struct cgroup_subsys_state *css;
+ struct cpuset *c, *par;
+ int ret;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ /* Each of our child cpusets must be a subset of us */
+ ret = -EBUSY;
+ cpuset_for_each_child(c, css, cur)
+ if (!is_cpuset_subset(c, trial))
+ goto out;
+
+ /* On legacy hierarchy, we must be a subset of our parent cpuset. */
+ ret = -EACCES;
+ par = parent_cs(cur);
+ if (par && !is_cpuset_subset(trial, par))
+ goto out;
+
+ ret = 0;
+out:
+ return ret;
+}
+
+/*
* validate_change() - Used to validate that any proposed cpuset change
* follows the structural rules for cpusets.
*
@@ -614,20 +643,21 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
{
struct cgroup_subsys_state *css;
struct cpuset *c, *par;
- int ret;
-
- /* The checks don't apply to root cpuset */
- if (cur == &top_cpuset)
- return 0;
+ int ret = 0;
rcu_read_lock();
- par = parent_cs(cur);
- /* On legacy hierarchy, we must be a subset of our parent cpuset. */
- ret = -EACCES;
- if (!is_in_v2_mode() && !is_cpuset_subset(trial, par))
+ if (!is_in_v2_mode())
+ ret = validate_change_legacy(cur, trial);
+ if (ret)
+ goto out;
+
+ /* Remaining checks don't apply to root cpuset */
+ if (cur == &top_cpuset)
goto out;
+ par = parent_cs(cur);
+
/*
* If either I or some sibling (!= me) is exclusive, we can't
* overlap
@@ -1175,9 +1205,7 @@ enum subparts_cmd {
*
* Because of the implicit cpu exclusive nature of a partition root,
* cpumask changes that violates the cpu exclusivity rule will not be
- * permitted when checked by validate_change(). The validate_change()
- * function will also prevent any changes to the cpu list if it is not
- * a superset of children's cpu lists.
+ * permitted when checked by validate_change().
*/
static int update_parent_subparts_cpumask(struct cpuset *cpuset, int cmd,
struct cpumask *newmask,
@@ -1522,10 +1550,15 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
struct cpuset *sibling;
struct cgroup_subsys_state *pos_css;
+ percpu_rwsem_assert_held(&cpuset_rwsem);
+
/*
* Check all its siblings and call update_cpumasks_hier()
* if their use_parent_ecpus flag is set in order for them
* to use the right effective_cpus value.
+ *
+ * The update_cpumasks_hier() function may sleep. So we have to
+ * release the RCU read lock before calling it.
*/
rcu_read_lock();
cpuset_for_each_child(sibling, pos_css, parent) {
@@ -1533,8 +1566,13 @@ static void update_sibling_cpumasks(struct cpuset *parent, struct cpuset *cs,
continue;
if (!sibling->use_parent_ecpus)
continue;
+ if (!css_tryget_online(&sibling->css))
+ continue;
+ rcu_read_unlock();
update_cpumasks_hier(sibling, tmp);
+ rcu_read_lock();
+ css_put(&sibling->css);
}
rcu_read_unlock();
}
@@ -1607,8 +1645,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
* Make sure that subparts_cpus is a subset of cpus_allowed.
*/
if (cs->nr_subparts_cpus) {
- cpumask_andnot(cs->subparts_cpus, cs->subparts_cpus,
- cs->cpus_allowed);
+ cpumask_and(cs->subparts_cpus, cs->subparts_cpus, cs->cpus_allowed);
cs->nr_subparts_cpus = cpumask_weight(cs->subparts_cpus);
}
spin_unlock_irq(&callback_lock);
@@ -2252,6 +2289,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
cgroup_taskset_first(tset, &css);
cs = css_cs(css);
+ cpus_read_lock();
percpu_down_write(&cpuset_rwsem);
guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
@@ -2305,6 +2343,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
wake_up(&cpuset_attach_wq);
percpu_up_write(&cpuset_rwsem);
+ cpus_read_unlock();
}
/* The various types of files and directories in a cpuset file system */
@@ -3485,8 +3524,8 @@ static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs)
return cs;
}
-/**
- * cpuset_node_allowed - Can we allocate on a memory node?
+/*
+ * __cpuset_node_allowed - Can we allocate on a memory node?
* @node: is this an allowed node?
* @gfp_mask: memory allocation flags
*
@@ -3657,8 +3696,8 @@ void cpuset_print_current_mems_allowed(void)
int cpuset_memory_pressure_enabled __read_mostly;
-/**
- * cpuset_memory_pressure_bump - keep stats of per-cpuset reclaims.
+/*
+ * __cpuset_memory_pressure_bump - keep stats of per-cpuset reclaims.
*
* Keep a running average of the rate of synchronous (direct)
* page reclaim efforts initiated by tasks in each cpuset.
@@ -3673,7 +3712,7 @@ int cpuset_memory_pressure_enabled __read_mostly;
* "memory_pressure". Value displayed is an integer
* representing the recent rate of entry into the synchronous
* (direct) page reclaim by any task attached to the cpuset.
- **/
+ */
void __cpuset_memory_pressure_bump(void)
{