/* vmpressure notifications */
struct vmpressure vmpressure;
+ /* css_online() has been completed */
+ int initialized;
+
/*
* the counter to account for mem+swap usage.
*/
* skipping css reference should be safe.
*/
if (next_css) {
- if ((next_css == &root->css) ||
- ((next_css->flags & CSS_ONLINE) &&
- css_tryget_online(next_css)))
- return mem_cgroup_from_css(next_css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(next_css);
+
+ if (next_css == &root->css)
+ return memcg;
+
+ if (css_tryget_online(next_css)) {
+ /*
+ * Make sure the memcg is initialized:
+ * mem_cgroup_css_online() orders the the
+ * initialization against setting the flag.
+ */
+ if (smp_load_acquire(&memcg->initialized))
+ return memcg;
+ css_put(next_css);
+ }
prev_css = next_css;
goto skip_node;
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup *parent = mem_cgroup_from_css(css->parent);
+ int ret;
if (css->id > MEM_CGROUP_ID_MAX)
return -ENOSPC;
}
mutex_unlock(&memcg_create_mutex);
- return memcg_init_kmem(memcg, &memory_cgrp_subsys);
+ ret = memcg_init_kmem(memcg, &memory_cgrp_subsys);
+ if (ret)
+ return ret;
+
+ /*
+ * Make sure the memcg is initialized: mem_cgroup_iter()
+ * orders reading memcg->initialized against its callers
+ * reading the memcg members.
+ */
+ smp_store_release(&memcg->initialized, 1);
+
+ return 0;
}
/*