[PATCH 3/3] mm/slab: use list_{empty_careful,last_entry} in drain_freelist

Geliang Tang
2015-12-02T15:47:14Z

To simplify the code, use list_empty_careful instead of list_empty.
To make the intention clearer, use list_last_entry instead of list_entry.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
mm/slab.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 5d5aa3b..1a7d91c 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2362,21 +2362,14 @@ static void drain_cpu_caches(struct kmem_cache *cachep)
static int drain_freelist(struct kmem_cache *cache,
struct kmem_cache_node *n, int tofree)
{
- struct list_head *p;
int nr_freed;
struct page *page;

nr_freed = 0;
- while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
+ while (nr_freed < tofree && !list_empty_careful(&n->slabs_free)) {

spin_lock_irq(&n->list_lock);
- p = n->slabs_free.prev;
- if (p == &n->slabs_free) {
- spin_unlock_irq(&n->list_lock);
- goto out;
- }
-
- page = list_entry(p, struct page, lru);
+ page = list_last_entry(&n->slabs_free, struct page, lru);
#if DEBUG
BUG_ON(page->active);
#endif
@@ -2390,7 +2383,6 @@ static int drain_freelist(struct kmem_cache *cache,
slab_destroy(cache, page);
nr_freed++;
}
-out:
return nr_freed;
}

--
2.5.0