[PATCH net-next v3] page_pool: use relaxed atomic for release side accounting

From: Yunsheng Lin
Date: Tue Aug 24 2021 - 05:08:07 EST


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: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
Signed-off-by: Yunsheng Lin <linyunsheng@xxxxxxxxxx>
---
V3: Drop patch 2.
V2: Remove unnecessary unliky() mark as pointed out by
Heiner.
---
net/core/page_pool.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index e140905..1a69784 100644
--- a/net/core/page_pool.c
+++ b/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);
--
2.7.4