UPSTREAM: mm: slub: only warn once when allocating slab obj extensions fails

In memory bound systems, a large number of warnings for failing this
allocation repeatedly may mask any real issues in the system
during memory pressure being reported in dmesg. Change this to
warning only once.

Bug: 437294717
Change-Id: I2f1b9ebac0a7650acd74b1dc75967ea87c1c12d4
Signed-off-by: Usama Arif <usamaarif642@gmail.com>
Reported-by: Vlad Poenaru <vlad.wing@gmail.com>
Closes: https://lore.kernel.org/all/17fab2d6-5a74-4573-bcc3-b75951508f0a@gmail.com/
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
(cherry picked from commit 354ad60e123dad8e231e7443735020806f3c57d0)

mm/slub.c

diff --git a/mm/slub.c b/mm/slub.c
index e925976..53e6b6b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2121,10 +2121,11 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
 
 	slab = virt_to_slab(p);
 	if (!slab_obj_exts(slab) &&
-	    WARN(alloc_slab_obj_exts(slab, s, flags, false),
-		 "%s, %s: Failed to create slab extension vector!\n",
-		 __func__, s->name))
+	    alloc_slab_obj_exts(slab, s, flags, false)) {
+		pr_warn_once("%s, %s: Failed to create slab extension vector!\n",
+			     __func__, s->name);
 		return NULL;
+	}
 
 	return slab_obj_exts(slab) + obj_to_index(s, slab, p);
 }