2015-12-03 14:15:08

by Geliang Tang

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

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

Signed-off-by: Geliang Tang <[email protected]>
---
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

2015-12-03 14:48:07

by Christoph Lameter (Ampere)

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

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 <[email protected]>

2015-12-03 21:02:28

by David Rientjes

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

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 <[email protected]>

Acked-by: David Rientjes <[email protected]>