From: Christoph Lameter <cl@xxxxxxxxx> Subject: slub: Remove userspace notifier for cache add/remove I came across some unnecessary uevents once again which reminded me this. The patch seems to be lost in the leaves of the original discussion [1], so resending. [1] https://lore.kernel.org/r/alpine.DEB.2.21.2001281813130.745@xxxxxxxxxxxxxxx Kmem caches are internal kernel structures so it is strange that userspace notifiers would be needed. And I am not aware of any use of these notifiers. These notifiers may just exist because in the initial slub release the sysfs code was copied from another subsystem. Link: http://lkml.kernel.org/r/20200423115721.19821-1-mkoutny@xxxxxxxx Signed-off-by: Christoph Lameter <cl@xxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Michal Koutný <mkoutny@xxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 17 +---------------- 1 file changed, 1 insertion(+), 16 deletions(-) --- a/mm/slub.c~slub-remove-userspace-notifier-for-cache-add-remove +++ a/mm/slub.c @@ -5715,19 +5715,6 @@ static struct kobj_type slab_ktype = { .release = kmem_cache_release, }; -static int uevent_filter(struct kset *kset, struct kobject *kobj) -{ - struct kobj_type *ktype = get_ktype(kobj); - - if (ktype == &slab_ktype) - return 1; - return 0; -} - -static const struct kset_uevent_ops slab_uevent_ops = { - .filter = uevent_filter, -}; - static struct kset *slab_kset; static inline struct kset *cache_kset(struct kmem_cache *s) @@ -5795,7 +5782,6 @@ static void sysfs_slab_remove_workfn(str #ifdef CONFIG_MEMCG kset_unregister(s->memcg_kset); #endif - kobject_uevent(&s->kobj, KOBJ_REMOVE); out: kobject_put(&s->kobj); } @@ -5853,7 +5839,6 @@ static int sysfs_slab_add(struct kmem_ca } #endif - kobject_uevent(&s->kobj, KOBJ_ADD); if (!unmergeable) { /* Setup first alias */ sysfs_slab_alias(s, s->name); @@ -5934,7 +5919,7 @@ static int __init slab_sysfs_init(void) mutex_lock(&slab_mutex); - slab_kset = kset_create_and_add("slab", &slab_uevent_ops, kernel_kobj); + slab_kset = kset_create_and_add("slab", NULL, kernel_kobj); if (!slab_kset) { mutex_unlock(&slab_mutex); pr_err("Cannot register slab subsystem.\n"); _