The patch titled
Subject: mm/slab: align cache size first before determination of OFF_SLAB candidate
has been added to the -mm tree. Its filename is
mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate.patch
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------------------------------------------------------
From: Joonsoo Kim <js1304@xxxxxxxxx>
Subject: mm/slab: align cache size first before determination of OFF_SLAB candidate
Finding suitable OFF_SLAB candidate is more related to aligned cache size
rather than original size. Same reasoning can be applied to the debug
pagealloc candidate. So, this patch moves up alignment fixup to proper
position. From that point, size is aligned so we can remove some
alignment fixups.
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slab.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)
diff -puN mm/slab.c~mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate mm/slab.c
--- a/mm/slab.c~mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate
+++ a/mm/slab.c
@@ -2126,6 +2126,17 @@ __kmem_cache_create (struct kmem_cache *
else
size += BYTES_PER_WORD;
}
+#endif
+
+ size = ALIGN(size, cachep->align);
+ /*
+ * We should restrict the number of objects in a slab to implement
+ * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
+ */
+ if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
+ size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
+
+#if DEBUG
/*
* To activate debug pagealloc, off-slab management is necessary
* requirement. In early phase of initialization, small sized slab
@@ -2136,8 +2147,8 @@ __kmem_cache_create (struct kmem_cache *
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) {
- cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align);
+ size < PAGE_SIZE) {
+ cachep->obj_offset += PAGE_SIZE - size;
size = PAGE_SIZE;
}
#endif
@@ -2149,20 +2160,13 @@ __kmem_cache_create (struct kmem_cache *
* SLAB_NOLEAKTRACE to avoid recursive calls into kmemleak)
*/
if (size >= OFF_SLAB_MIN_SIZE && !slab_early_init &&
- !(flags & SLAB_NOLEAKTRACE))
+ !(flags & SLAB_NOLEAKTRACE)) {
/*
* Size is large, assume best to place the slab management obj
* off-slab (should allow better packing of objs).
*/
flags |= CFLGS_OFF_SLAB;
-
- size = ALIGN(size, cachep->align);
- /*
- * We should restrict the number of objects in a slab to implement
- * byte sized index. Refer comment on SLAB_OBJ_MIN_SIZE definition.
- */
- if (FREELIST_BYTE_INDEX && size < SLAB_OBJ_MIN_SIZE)
- size = ALIGN(SLAB_OBJ_MIN_SIZE, cachep->align);
+ }
left_over = calculate_slab_order(cachep, size, flags);
_
Patches currently in -mm which might be from js1304@xxxxxxxxx are
mm-slab-fix-stale-code-comment.patch
mm-slab-remove-useless-structure-define.patch
mm-slab-remove-the-checks-for-slab-implementation-bug.patch
mm-slab-activate-debug_pagealloc-in-slab-when-it-is-actually-enabled.patch
mm-slab-use-more-appropriate-condition-check-for-debug_pagealloc.patch
mm-slab-clean-up-debug_pagealloc-processing-code.patch
mm-slab-alternative-implementation-for-debug_slab_leak.patch
mm-slab-remove-object-status-buffer-for-debug_slab_leak.patch
mm-slab-put-the-freelist-at-the-end-of-slab-page.patch
mm-slab-align-cache-size-first-before-determination-of-off_slab-candidate.patch
mm-slab-clean-up-cache-type-determination.patch
mm-slab-do-not-change-cache-size-if-debug-pagealloc-isnt-possible.patch
mm-slab-make-criteria-for-off-slab-determination-robust-and-simple.patch
mm-slab-factor-out-slab-list-fixup-code.patch
mm-slab-factor-out-debugging-initialization-in-cache_init_objs.patch
mm-slab-introduce-new-slab-management-type-objfreelist_slab.patch
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