+ slub-remove-userspace-notifier-for-cache-add-remove.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: slub: Remove userspace notifier for cache add/remove
has been added to the -mm tree.  Its filename is
     slub-remove-userspace-notifier-for-cache-add-remove.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/slub-remove-userspace-notifier-for-cache-add-remove.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/slub-remove-userspace-notifier-for-cache-add-remove.patch

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------------------------------------------------------
From: Christoph Lameter <cl@linux.com>
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@www.lameter.com

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@suse.com
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Koutný <mkoutny@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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
@@ -5700,19 +5700,6 @@ 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)
@@ -5780,7 +5767,6 @@ 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);
 }
@@ -5838,7 +5824,6 @@ 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);
@@ -5919,7 +5904,7 @@ 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");
_

Patches currently in -mm which might be from cl@linux.com are

slub-remove-userspace-notifier-for-cache-add-remove.patch