[PATCH net-next] page_pool: remove spinlock in page_pool_refill_alloc_cache()

From: Yunsheng Lin
Date: Fri Jan 07 2022 - 04:00:20 EST


As page_pool_refill_alloc_cache() is only called by
__page_pool_get_cached(), which assumes non-concurrent access
as suggested by the comment in __page_pool_get_cached(), and
ptr_ring allows concurrent access between consumer and producer,
so remove the spinlock in page_pool_refill_alloc_cache().

Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
net/core/page_pool.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 1a6978427d6c..6efad8b29e9c 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -130,9 +130,6 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
pref_nid = numa_mem_id(); /* will be zero like page_to_nid() */
#endif

- /* Slower-path: Get pages from locked ring queue */
- spin_lock(&r->consumer_lock);
-
/* Refill alloc array, but only if NUMA match */
do {
page = __ptr_ring_consume(r);
@@ -157,7 +154,6 @@ static struct page *page_pool_refill_alloc_cache(struct page_pool *pool)
if (likely(pool->alloc.count > 0))
page = pool->alloc.cache[--pool->alloc.count];

- spin_unlock(&r->consumer_lock);
return page;
}

--
2.33.0