KAMEZAWA Hiroyuki wrote: > My main purpose of this patch is for memory controller.. > > This patch adds a handler "pre_destroy" to cgroup_subsys. > It is called before cgroup_rmdir() checks all subsys's refcnt. > > I think this is useful for subsyses which have some extra refs > even if there are no tasks in cgroup. > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > include/linux/cgroup.h | 1 + > kernel/cgroup.c | 7 +++++++ > 2 files changed, 8 insertions(+) > > Index: devel-2.6.23-mm1/include/linux/cgroup.h > =================================================================== > --- devel-2.6.23-mm1.orig/include/linux/cgroup.h > +++ devel-2.6.23-mm1/include/linux/cgroup.h > @@ -233,6 +233,7 @@ int cgroup_is_descendant(const struct cg > struct cgroup_subsys { > struct cgroup_subsys_state *(*create)(struct cgroup_subsys *ss, > struct cgroup *cont); > + void (*pre_destroy)(struct cgroup_subsys *ss, struct cgroup *cont); > void (*destroy)(struct cgroup_subsys *ss, struct cgroup *cont); > int (*can_attach)(struct cgroup_subsys *ss, > struct cgroup *cont, struct task_struct *tsk); > Index: devel-2.6.23-mm1/kernel/cgroup.c > =================================================================== > --- devel-2.6.23-mm1.orig/kernel/cgroup.c > +++ devel-2.6.23-mm1/kernel/cgroup.c > @@ -2158,6 +2158,13 @@ static int cgroup_rmdir(struct inode *un > parent = cont->parent; > root = cont->root; > sb = root->sb; > + /* > + * Notify subsyses that rmdir() request comes. > + */ > + for_each_subsys(root, ss) { > + if ((cont->subsys[ss->subsys_id]) && ss->pre_destroy) > + ss->pre_destroy(ss, cont); > + } > Is pre_destroy really required? Can't we do what we do here in destroy? > if (cgroup_has_css_refs(cont)) { > mutex_unlock(&cgroup_mutex); > -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers