Commit 8aba7e0a authored Oct 29, 2014 by Mikulas Patocka Committed by Linus Torvalds Oct 29, 2014

mm/slab_common: don't check for duplicate cache names



The SLUB cache merges caches with the same size and alignment and there
was long standing bug with this behavior:

 - create the cache named "foo"
 - create the cache named "bar" (which is merged with "foo")
 - delete the cache named "foo" (but it stays allocated because "bar"
   uses it)
 - create the cache named "foo" again - it fails because the name "foo"
   is already used

That bug was fixed in commit 69461747 ("slab_common: fix the check
for duplicate slab names") by not warning on duplicate cache names when
the SLUB subsystem is used.

Recently, cache merging was implemented the with SLAB subsystem too, in
12220dea ("mm/slab: support slab merge")).  Therefore we need stop
checking for duplicate names even for the SLAB subsystem.

This patch fixes the bug by removing the check.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent d3556bab

mm/slab_common.c

+0 −10

Original line number	Diff line number	Diff line
		@@ -93,16 +93,6 @@ static int kmem_cache_sanity_check(const char *name, size_t size)
		s->object_size);
		continue;
		}

		#if !defined(CONFIG_SLUB)
		if (!strcmp(s->name, name)) {
		pr_err("%s (%s): Cache name already exists.\n",
		__func__, name);
		dump_stack();
		s = NULL;
		return -EINVAL;
		}
		#endif
		}

		WARN_ON(strchr(name, ' ')); /* It confuses parsers */

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