Commit 8888177e authored May 19, 2016 by Joonsoo Kim Committed by Linus Torvalds May 19, 2016

mm/slab: remove BAD_ALIEN_MAGIC again



Initial attemp to remove BAD_ALIEN_MAGIC is once reverted by 'commit
edcad250 ("Revert "slab: remove BAD_ALIEN_MAGIC"")' because it
causes a problem on m68k which has many node but !CONFIG_NUMA.  In this
case, although alien cache isn't used at all but to cope with some
initialization path, garbage value is used and that is BAD_ALIEN_MAGIC.
Now, this patch set use_alien_caches to 0 when !CONFIG_NUMA, there is no
initialization path problem so we don't need BAD_ALIEN_MAGIC at all.  So
remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 18726ca8

mm/slab.c

+2 −4

Original line number	Diff line number	Diff line
		@@ -421,8 +421,6 @@ static struct kmem_cache kmem_cache_boot = {
		.name = "kmem_cache",
		};

		#define BAD_ALIEN_MAGIC 0x01020304ul

		static DEFINE_PER_CPU(struct delayed_work, slab_reap_work);

		static inline struct array_cache cpu_cache_get(struct kmem_cache cachep)
		@@ -644,7 +642,7 @@ static int transfer_objects(struct array_cache *to,
		static inline struct alien_cache **alloc_alien_cache(int node,
		int limit, gfp_t gfp)
		{
		return (struct alien_cache **)BAD_ALIEN_MAGIC;
		return NULL;
		}

		static inline void free_alien_cache(struct alien_cache **ac_ptr)
		@@ -1212,7 +1210,7 @@ void __init kmem_cache_init(void)
		sizeof(struct rcu_head));
		kmem_cache = &kmem_cache_boot;

		if (num_possible_nodes() == 1)
		if (!IS_ENABLED(CONFIG_NUMA) \|\| num_possible_nodes() == 1)
		use_alien_caches = 0;

		for (i = 0; i < NUM_INIT_LISTS; i++)

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