page_pool: use relaxed atomic for release side accounting

mainline inclusion
from mainline-v5.15-rc1
commit 7fb9b66d
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4CVS3
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7fb9b66dc9ce

----------------------------------------------------------------------

There is no need to synchronize the account updating, so
use the relaxed atomic to avoid some memory barrier in the
data path.
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NYunsheng Lin <linyunsheng@huawei.com>
Acked-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NYongxin Li <liyongxin1@huawei.com>
Signed-off-by: NJunxin Chen <chenjunxin1@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

net/core/page_pool.c

@@ -370,7 +370,7 @@ void page_pool_release_page(struct page_pool *pool, struct page *page)
 	/* This may be the last page returned, releasing the pool, so
 	 * it is not safe to reference pool afterwards.
 	 */
-	count = atomic_inc_return(&pool->pages_state_release_cnt);
+	count = atomic_inc_return_relaxed(&pool->pages_state_release_cnt);
 	trace_page_pool_state_release(pool, page, count);
 }
 EXPORT_SYMBOL(page_pool_release_page);