[S+Q2 09/19] slub: discard_slab_unlock

[Christoph Lameter <cl@linux-foundation.org>]

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The sequence of unlocking a slab and freeing occurs multiple times.
Put the common into a single function. There is no intend here
to use this to enforce a sequencing of events leading up
to the discarding of a slab page.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>

---
 mm/slub.c |   16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2010-06-01 08:58:50.000000000 -0500
+++ linux-2.6/mm/slub.c	2010-06-01 08:58:54.000000000 -0500
@@ -1260,6 +1260,13 @@ static __always_inline int slab_trylock(
 	return rc;
 }
 
+static void discard_slab_unlock(struct kmem_cache *s,
+	struct page *page)
+{
+	slab_unlock(page);
+	discard_slab(s, page);
+}
+
 /*
  * Management of partially allocated slabs
  */
@@ -1437,9 +1444,8 @@ static void unfreeze_slab(struct kmem_ca
 			add_partial(n, page, 1);
 			slab_unlock(page);
 		} else {
-			slab_unlock(page);
 			stat(s, FREE_SLAB);
-			discard_slab(s, page);
+			discard_slab_unlock(s, page);
 		}
 	}
 }
@@ -1822,9 +1828,8 @@ slab_empty:
 		remove_partial(s, page);
 		stat(s, FREE_REMOVE_PARTIAL);
 	}
-	slab_unlock(page);
 	stat(s, FREE_SLAB);
-	discard_slab(s, page);
+	discard_slab_unlock(s, page);
 	return;
 
 debug:
@@ -2893,8 +2898,7 @@ int kmem_cache_shrink(struct kmem_cache 
 				 */
 				list_del(&page->lru);
 				n->nr_partial--;
-				slab_unlock(page);
-				discard_slab(s, page);
+				discard_slab_unlock(s, page);
 			} else {
 				list_move(&page->lru,
 				slabs_by_inuse + page->inuse);