mm/slub: remove obsolete comment
authorCanjiang Lu <canjiang.lu@samsung.com>
Fri, 8 Jun 2018 00:05:20 +0000 (17:05 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 8 Jun 2018 00:34:34 +0000 (17:34 -0700)
The obsolete comment removed in this patch was introduced by
51df1142816e4 ("slub: Dynamically size kmalloc cache allocations").

I paste related modification from that commit:

+#ifdef CONFIG_NUMA
+       /*
+        * Allocate kmem_cache_node properly from the kmem_cache slab.
+        * kmem_cache_node is separately allocated so no need to
+        * update any list pointers.
+        */
+       temp_kmem_cache_node = kmem_cache_node;

+       kmem_cache_node = kmem_cache_alloc(kmem_cache, GFP_NOWAIT);
+       memcpy(kmem_cache_node, temp_kmem_cache_node, kmem_size);
+
+       kmem_cache_bootstrap_fixup(kmem_cache_node);
+
+       caches++;
+#else
+       /*
+        * kmem_cache has kmem_cache_node embedded and we moved it!
+        * Update the list heads
+        */
+       INIT_LIST_HEAD(&kmem_cache->local_node.partial);
+       list_splice(&temp_kmem_cache->local_node.partial, &kmem_cache->local_node.partial);
+#ifdef CONFIG_SLUB_DEBUG
+       INIT_LIST_HEAD(&kmem_cache->local_node.full);
+       list_splice(&temp_kmem_cache->local_node.full, &kmem_cache->local_node.full);
+#endif

As we can see there're used to distinguish the difference handling
between NUMA/non-NUMA configuration in the original commit.  I think it
doesn't make any sense in current implementation which is placed above
kmem_cache_node = bootstrap(&boot_kmem_cache_node); So maybe it's better
to remove them now?

Link: http://lkml.kernel.org/r/5af26f58.1c69fb81.1be0e.c520SMTPIN_ADDED_BROKEN@mx.google.com
Signed-off-by: Canjiang Lu <canjiang.lu@samsung.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>
mm/slub.c

index ec5916483b07f4e0363ac9d1e24d26bfb879a382..48f75872c35692b1c627765add13030e31941d42 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4241,12 +4241,6 @@ void __init kmem_cache_init(void)
                       SLAB_HWCACHE_ALIGN, 0, 0);
 
        kmem_cache = bootstrap(&boot_kmem_cache);
-
-       /*
-        * Allocate kmem_cache_node properly from the kmem_cache slab.
-        * kmem_cache_node is separately allocated so no need to
-        * update any list pointers.
-        */
        kmem_cache_node = bootstrap(&boot_kmem_cache_node);
 
        /* Now we can use the kmem_cache to allocate kmalloc slabs */