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-rw-r--r--kernel/cpuset.c96
1 files changed, 46 insertions, 50 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 2bb8c2e98fff..55b297d78adc 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1367,14 +1367,10 @@ static int fmeter_getrate(struct fmeter *fmp)
return val;
}
-/* Protected by cgroup_lock */
-static cpumask_var_t cpus_attach;
-
/* Called by cgroups to determine if a cpuset is usable; cgroup_mutex held */
static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct task_struct *tsk, bool threadgroup)
+ struct task_struct *tsk)
{
- int ret;
struct cpuset *cs = cgroup_cs(cont);
if (cpumask_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed))
@@ -1391,29 +1387,42 @@ static int cpuset_can_attach(struct cgroup_subsys *ss, struct cgroup *cont,
if (tsk->flags & PF_THREAD_BOUND)
return -EINVAL;
- ret = security_task_setscheduler(tsk);
- if (ret)
- return ret;
- if (threadgroup) {
- struct task_struct *c;
-
- rcu_read_lock();
- list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
- ret = security_task_setscheduler(c);
- if (ret) {
- rcu_read_unlock();
- return ret;
- }
- }
- rcu_read_unlock();
- }
return 0;
}
-static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to,
- struct cpuset *cs)
+static int cpuset_can_attach_task(struct cgroup *cgrp, struct task_struct *task)
+{
+ return security_task_setscheduler(task);
+}
+
+/*
+ * Protected by cgroup_lock. The nodemasks must be stored globally because
+ * dynamically allocating them is not allowed in pre_attach, and they must
+ * persist among pre_attach, attach_task, and attach.
+ */
+static cpumask_var_t cpus_attach;
+static nodemask_t cpuset_attach_nodemask_from;
+static nodemask_t cpuset_attach_nodemask_to;
+
+/* Set-up work for before attaching each task. */
+static void cpuset_pre_attach(struct cgroup *cont)
+{
+ struct cpuset *cs = cgroup_cs(cont);
+
+ if (cs == &top_cpuset)
+ cpumask_copy(cpus_attach, cpu_possible_mask);
+ else
+ guarantee_online_cpus(cs, cpus_attach);
+
+ guarantee_online_mems(cs, &cpuset_attach_nodemask_to);
+}
+
+/* Per-thread attachment work. */
+static void cpuset_attach_task(struct cgroup *cont, struct task_struct *tsk)
{
int err;
+ struct cpuset *cs = cgroup_cs(cont);
+
/*
* can_attach beforehand should guarantee that this doesn't fail.
* TODO: have a better way to handle failure here
@@ -1421,45 +1430,29 @@ static void cpuset_attach_task(struct task_struct *tsk, nodemask_t *to,
err = set_cpus_allowed_ptr(tsk, cpus_attach);
WARN_ON_ONCE(err);
- cpuset_change_task_nodemask(tsk, to);
+ cpuset_change_task_nodemask(tsk, &cpuset_attach_nodemask_to);
cpuset_update_task_spread_flag(cs, tsk);
-
}
static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont,
- struct cgroup *oldcont, struct task_struct *tsk,
- bool threadgroup)
+ struct cgroup *oldcont, struct task_struct *tsk)
{
struct mm_struct *mm;
struct cpuset *cs = cgroup_cs(cont);
struct cpuset *oldcs = cgroup_cs(oldcont);
- static nodemask_t to; /* protected by cgroup_mutex */
- if (cs == &top_cpuset) {
- cpumask_copy(cpus_attach, cpu_possible_mask);
- } else {
- guarantee_online_cpus(cs, cpus_attach);
- }
- guarantee_online_mems(cs, &to);
-
- /* do per-task migration stuff possibly for each in the threadgroup */
- cpuset_attach_task(tsk, &to, cs);
- if (threadgroup) {
- struct task_struct *c;
- rcu_read_lock();
- list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {
- cpuset_attach_task(c, &to, cs);
- }
- rcu_read_unlock();
- }
-
- /* change mm; only needs to be done once even if threadgroup */
- to = cs->mems_allowed;
+ /*
+ * Change mm, possibly for multiple threads in a threadgroup. This is
+ * expensive and may sleep.
+ */
+ cpuset_attach_nodemask_from = oldcs->mems_allowed;
+ cpuset_attach_nodemask_to = cs->mems_allowed;
mm = get_task_mm(tsk);
if (mm) {
- mpol_rebind_mm(mm, &to);
+ mpol_rebind_mm(mm, &cpuset_attach_nodemask_to);
if (is_memory_migrate(cs))
- cpuset_migrate_mm(mm, &oldcs->mems_allowed, &to);
+ cpuset_migrate_mm(mm, &cpuset_attach_nodemask_from,
+ &cpuset_attach_nodemask_to);
mmput(mm);
}
}
@@ -1911,6 +1904,9 @@ struct cgroup_subsys cpuset_subsys = {
.create = cpuset_create,
.destroy = cpuset_destroy,
.can_attach = cpuset_can_attach,
+ .can_attach_task = cpuset_can_attach_task,
+ .pre_attach = cpuset_pre_attach,
+ .attach_task = cpuset_attach_task,
.attach = cpuset_attach,
.populate = cpuset_populate,
.post_clone = cpuset_post_clone,