[PATCH] mm/slab.c: add a helper function get_first_slab

[PATCH] mm/slab.c: add a helper function get_first_slab

[Geliang Tang]

Add a new helper function get_first_slab() that get the first slab
from a kmem_cache_node.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
 mm/slab.c | 39 +++++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 18 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 925921e..2463b57 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2754,6 +2754,21 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 #define cache_free_debugcheck(x,objp,z) (objp)
 #endif
 
+static struct page *get_first_slab(struct kmem_cache_node *n)
+{
+	struct page *page;
+
+	page = list_first_entry_or_null(&n->slabs_partial,
+			struct page, lru);
+	if (!page) {
+		n->free_touched = 1;
+		page = list_first_entry_or_null(&n->slabs_free,
+				struct page, lru);
+	}
+
+	return page;
+}
+
 static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags,
 							bool force_refill)
 {
@@ -2791,15 +2806,9 @@ retry:
 	while (batchcount > 0) {
 		struct page *page;
 		/* Get slab alloc is to come from. */
-		page = list_first_entry_or_null(&n->slabs_partial,
-				struct page, lru);
-		if (!page) {
-			n->free_touched = 1;
-			page = list_first_entry_or_null(&n->slabs_free,
-					struct page, lru);
-			if (!page)
-				goto must_grow;
-		}
+		page = get_first_slab(n);
+		if (!page)
+			goto must_grow;
 
 		check_spinlock_acquired(cachep);
 
@@ -3095,15 +3104,9 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
 retry:
 	check_irq_off();
 	spin_lock(&n->list_lock);
-	page = list_first_entry_or_null(&n->slabs_partial,
-			struct page, lru);
-	if (!page) {
-		n->free_touched = 1;
-		page = list_first_entry_or_null(&n->slabs_free,
-				struct page, lru);
-		if (!page)
-			goto must_grow;
-	}
+	page = get_first_slab(n);
+	if (!page)
+		goto must_grow;
 
 	check_spinlock_acquired_node(cachep, nodeid);
 
-- 
2.5.0


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Re: [PATCH] mm/slab.c: add a helper function get_first_slab

[Christoph Lameter]

On Thu, 3 Dec 2015, Geliang Tang wrote:

> Add a new helper function get_first_slab() that get the first slab
> from a kmem_cache_node.

Acked-by: Christoph Lameter <cl@linux.com>

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Re: [PATCH] mm/slab.c: add a helper function get_first_slab

[David Rientjes]

On Thu, 3 Dec 2015, Geliang Tang wrote:

> Add a new helper function get_first_slab() that get the first slab
> from a kmem_cache_node.
> 
> Signed-off-by: Geliang Tang <geliangtang@163.com>

Acked-by: David Rientjes <rientjes@google.com>

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