[PATCH next 2/3] slub defrag: dma_kmalloc_cache add_tail

[Hugh Dickins <hugh@veritas.com>]

Why did that slowdown from mispinned pages manifest only on the G5?

Because something in my x86_32 and x86_64 configs (CONFIG_BLK_DEV_SR
I believe) is giving me a kmalloc_dma-512 cache, and dma_kmalloc_cache()
had not been updated to satisfy the assumption in kmem_cache_defrag(),
that defragmentable caches come first in the list.

So, any DMAable cache was preventing all slub defragmentation: which
looks like it's not been getting the testing exposure it deserves.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
---

 mm/slub.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 2.6.27-rc7-mmotm/mm/slub.c	2008-09-26 13:18:53.000000000 +0100
+++ linux/mm/slub.c	2008-10-04 20:10:46.000000000 +0100
@@ -2636,7 +2636,7 @@ static noinline struct kmem_cache *dma_k
 		goto unlock_out;
 	}
 
-	list_add(&s->list, &slab_caches);
+	list_add_tail(&s->list, &slab_caches);
 	kmalloc_caches_dma[index] = s;
 
 	schedule_work(&sysfs_add_work);

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