Hello, Zhang. On Mon, Dec 14, 2015 at 07:45:54PM +0800, [email protected] wrote: > @@ -2147,6 +2147,13 @@ static void cgroup_kill_sb(struct super_block *sb) > { > struct kernfs_root *kf_root = kernfs_root_from_sb(sb); > struct cgroup_root *root = cgroup_root_from_kf(kf_root); > + struct cgroup *child; > + int live_child = 0; > + > + mutex_lock(&cgroup_mutex); > + cgroup_for_each_live_child(child, &root->cgrp) { > + live_child++; > + } > > /* > * If @root doesn't have any mounts or children, start killing it. > @@ -2155,12 +2162,12 @@ static void cgroup_kill_sb(struct super_block *sb) > * > * And don't kill the default root. > */ > - if (!list_empty(&root->cgrp.self.children) || > - root == &cgrp_dfl_root) > - cgroup_put(&root->cgrp); > + if (live_child || root == &cgrp_dfl_root) > + cgroup_put(&root->cgrp); > else > percpu_ref_kill(&root->cgrp.self.refcnt); > > + mutex_unlock(&cgroup_mutex); > kernfs_kill_sb(sb);
I don't know. With the above change, we might fail remounting with the same option for some controllers which keep residual objects around. Changing controller associations has never been supported correctly and I don't think it'll ever be. I have no objection to improving it but this has the potential to regress use cases which would be more common. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
