page_pool: remove spinlock in page_pool_refill_alloc_cache()

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@huawei.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/r/20220107090042.13605-1-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 7347d5c7dbe090a94b26239757386d216df00ca0..bd62c01a2ec37562ec4208d7cedb497469c29626 100644 (file)
--- 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;
 }