Hello, Andrew. On Mon, Feb 06, 2017 at 04:22:13PM -0800, Andrew Morton wrote: > > #ifdef CONFIG_MEMCG > > - if (is_root_cache(s)) { > > + if (is_root_cache(s) && memcg_sysfs_enabled) { > > This could be turned on and off after bootup but I guess the result > could be pretty confusing. > > However there would be useful use cases? The user would normally have > this disabled but if he wants to do a bit of debugging then turn this > on, create a memcg, have a poke around then turn the feature off again. Hmm... maybe. It's somewhat nasty to do after-the-fact. You would have to re-walk all the caches to create and destroy the sysfs entries. Given that it's a pretty fringe debug feature, I'm not sure the added complexity would be justified. > > s->memcg_kset = kset_create_and_add("cgroup", NULL, &s->kobj); > > if (!s->memcg_kset) { > > err = -ENOMEM; > > @@ -5673,7 +5695,8 @@ static void sysfs_slab_remove(struct kme > > return; > > > > #ifdef CONFIG_MEMCG > > - kset_unregister(s->memcg_kset); > > + if (s->memcg_kset) > > + kset_unregister(s->memcg_kset); > > kset_unregister(NULL) is legal > > --- a/mm/slub.c~slub-make-sysfs-directories-for-memcg-sub-caches-optional-fix > +++ a/mm/slub.c > @@ -5699,8 +5699,7 @@ static void sysfs_slab_remove(struct kme > return; > > #ifdef CONFIG_MEMCG > - if (s->memcg_kset) > - kset_unregister(s->memcg_kset); > + kset_unregister(s->memcg_kset); > #endif > kobject_uevent(&s->kobj, KOBJ_REMOVE); > kobject_del(&s->kobj); Ah, of course, looks good to me. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>