DEBUG: sched: add tracepoint for task load/util signals

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

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 470f6536b9e8cfb029eedb5ecdb3c3e8c3c341be..fb1ecfd2decd907e907d1d68d74792cb6d07714e 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -57,7 +57,7 @@
 #include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
 #include <linux/kthread.h>
 #include <linux/delay.h>
-
+#include <linux/cpuset.h>
 #include <linux/atomic.h>
 
 /*
@@ -2764,6 +2764,7 @@ out_unlock_rcu:
 out_unlock_threadgroup:
        percpu_up_write(&cgroup_threadgroup_rwsem);
        cgroup_kn_unlock(of->kn);
+       cpuset_post_attach_flush();
        return ret ?: nbytes;
 }
 
@@ -4783,6 +4784,7 @@ static void init_and_link_css(struct cgroup_subsys_state *css,
        INIT_LIST_HEAD(&css->sibling);
        INIT_LIST_HEAD(&css->children);
        css->serial_nr = css_serial_nr_next++;
+       atomic_set(&css->online_cnt, 0);
 
        if (cgroup_parent(cgrp)) {
                css->parent = cgroup_css(cgroup_parent(cgrp), ss);
@@ -4805,6 +4807,10 @@ static int online_css(struct cgroup_subsys_state *css)
        if (!ret) {
                css->flags |= CSS_ONLINE;
                rcu_assign_pointer(css->cgroup->subsys[ss->id], css);
+
+               atomic_inc(&css->online_cnt);
+               if (css->parent)
+                       atomic_inc(&css->parent->online_cnt);
        }
        return ret;
 }
@@ -5036,10 +5042,15 @@ static void css_killed_work_fn(struct work_struct *work)
                container_of(work, struct cgroup_subsys_state, destroy_work);
 
        mutex_lock(&cgroup_mutex);
-       offline_css(css);
-       mutex_unlock(&cgroup_mutex);
 
-       css_put(css);
+       do {
+               offline_css(css);
+               css_put(css);
+               /* @css can't go away while we're holding cgroup_mutex */
+               css = css->parent;
+       } while (css && atomic_dec_and_test(&css->online_cnt));
+
+       mutex_unlock(&cgroup_mutex);
 }
 
 /* css kill confirmation processing requires process context, bounce */
@@ -5048,8 +5059,10 @@ static void css_killed_ref_fn(struct percpu_ref *ref)
        struct cgroup_subsys_state *css =
                container_of(ref, struct cgroup_subsys_state, refcnt);
 
-       INIT_WORK(&css->destroy_work, css_killed_work_fn);
-       queue_work(cgroup_destroy_wq, &css->destroy_work);
+       if (atomic_dec_and_test(&css->online_cnt)) {
+               INIT_WORK(&css->destroy_work, css_killed_work_fn);
+               queue_work(cgroup_destroy_wq, &css->destroy_work);
+       }
 }
 
 /**