[PATCH RESEND] slub: Remove userspace notifier for cache add/remove

From: Michal KoutnÃ
Date: Thu Apr 23 2020 - 07:57:32 EST


From: Christoph Lameter <cl@xxxxxxxxx>

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

8<---
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.

Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Michal Koutnà <mkoutny@xxxxxxxx>
---
mm/slub.c | 17 +----------------
1 file changed, 1 insertion(+), 16 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 332d4b459a90..ae6116adf875 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5665,19 +5665,6 @@ 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)
@@ -5745,7 +5732,6 @@ static void sysfs_slab_remove_workfn(struct work_struct *work)
#ifdef CONFIG_MEMCG
kset_unregister(s->memcg_kset);
#endif
- kobject_uevent(&s->kobj, KOBJ_REMOVE);
out:
kobject_put(&s->kobj);
}
@@ -5803,7 +5789,6 @@ static int sysfs_slab_add(struct kmem_cache *s)
}
#endif

- kobject_uevent(&s->kobj, KOBJ_ADD);
if (!unmergeable) {
/* Setup first alias */
sysfs_slab_alias(s, s->name);
@@ -5884,7 +5869,7 @@ 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");
--
2.26.0