[PATCH 4.4-cip 2/5] mm/slab: use more appropriate condition check for debug_pagealloc


Ben Hutchings <ben.hutchings@...>
 

From: Joonsoo Kim <iamjoonsoo.kim@...>

commit 40323278b557a5909bbecfa181c91a3af7afbbe3 upstream.

debug_pagealloc debugging is related to SLAB_POISON flag rather than
FORCED_DEBUG option, although FORCED_DEBUG option will enable
SLAB_POISON. Fix it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@...>
Acked-by: Christoph Lameter <cl@...>
Cc: Pekka Enberg <penberg@...>
Cc: David Rientjes <rientjes@...>
Cc: Joonsoo Kim <iamjoonsoo.kim@...>
Cc: Jesper Dangaard Brouer <brouer@...>
Signed-off-by: Andrew Morton <akpm@...>
Signed-off-by: Linus Torvalds <torvalds@...>
Signed-off-by: Ben Hutchings <ben.hutchings@...>
---
mm/slab.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index ed7eb6c92c81..62a7e4d3dde3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2180,7 +2180,6 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
else
size += BYTES_PER_WORD;
}
-#if FORCED_DEBUG && defined(CONFIG_DEBUG_PAGEALLOC)
/*
* To activate debug pagealloc, off-slab management is necessary
* requirement. In early phase of initialization, small sized slab
@@ -2188,7 +2187,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
* to check size >= 256. It guarantees that all necessary small
* sized slab is initialized in current slab initialization sequence.
*/
- if (debug_pagealloc_enabled() &&
+ if (debug_pagealloc_enabled() && (flags & SLAB_POISON) &&
!slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
size >= 256 && cachep->object_size > cache_line_size() &&
ALIGN(size, cachep->align) < PAGE_SIZE) {
@@ -2196,7 +2195,6 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
size = PAGE_SIZE;
}
#endif
-#endif

/*
* Determine if the slab management is 'on' or 'off' slab.
--
2.10.2



--
Ben Hutchings
Software Developer, Codethink Ltd.

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