arm64: dts: rockchip: rk3368: add qos node

[firefly-linux-kernel-4.4.55.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index e5bd044c1cbb4a412f7dedfcb8da29ac80f591b7..3f9db31c5d043287b7e566fdaace6446ee46e6a1 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -325,8 +325,7 @@ static struct file_system_type cpuset_fs_type = {
 /*
  * Return in pmask the portion of a cpusets's cpus_allowed that
  * are online.  If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online cpus.  The top
- * cpuset always has some cpus online.
+ * until we find one that does have some online cpus.
  *
  * One way or another, we guarantee to return some non-empty subset
  * of cpu_online_mask.
@@ -335,8 +334,20 @@ static struct file_system_type cpuset_fs_type = {
  */
 static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
 {
-       while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask))
+       while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) {
                cs = parent_cs(cs);
+               if (unlikely(!cs)) {
+                       /*
+                        * The top cpuset doesn't have any online cpu as a
+                        * consequence of a race between cpuset_hotplug_work
+                        * and cpu hotplug notifier.  But we know the top
+                        * cpuset's effective_cpus is on its way to to be
+                        * identical to cpu_online_mask.
+                        */
+                       cpumask_copy(pmask, cpu_online_mask);
+                       return;
+               }
+       }
        cpumask_and(pmask, cs->effective_cpus, cpu_online_mask);
 }
 
@@ -2084,23 +2095,6 @@ static void cpuset_bind(struct cgroup_subsys_state *root_css)
        mutex_unlock(&cpuset_mutex);
 }
 
-static int cpuset_allow_attach(struct cgroup_taskset *tset)
-{
-       const struct cred *cred = current_cred(), *tcred;
-       struct task_struct *task;
-       struct cgroup_subsys_state *css;
-
-       cgroup_taskset_for_each(task, css, tset) {
-               tcred = __task_cred(task);
-
-               if ((current != task) && !capable(CAP_SYS_ADMIN) &&
-                    cred->euid.val != tcred->uid.val && cred->euid.val != tcred->suid.val)
-                       return -EACCES;
-       }
-
-       return 0;
-}
-
 /*
  * Make sure the new task conform to the current state of its parent,
  * which could have been changed by cpuset just after it inherits the
@@ -2121,7 +2115,6 @@ struct cgroup_subsys cpuset_cgrp_subsys = {
        .css_offline    = cpuset_css_offline,
        .css_free       = cpuset_css_free,
        .can_attach     = cpuset_can_attach,
-       .allow_attach   = cpuset_allow_attach,
        .cancel_attach  = cpuset_cancel_attach,
        .attach         = cpuset_attach,
        .post_attach    = cpuset_post_attach,