netdev - [PATCH net-next 05/12] net: hns3: minor optimization for ring

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 3 Apr 2019 11:07:54 +0800
From:   Huazhong Tan <tanhuazhong@...wei.com>
To:     <davem@...emloft.net>
CC:     <netdev@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <salil.mehta@...wei.com>, <yisen.zhuang@...wei.com>,
        <linuxarm@...wei.com>, Yunsheng Lin <linyunsheng@...wei.com>,
        Peng Li <lipeng321@...wei.com>,
        Huazhong Tan <tanhuazhong@...wei.com>
Subject: [PATCH net-next 05/12] net: hns3: minor optimization for ring_space

From: Yunsheng Lin <linyunsheng@...wei.com>

This patch optimizes the ring_space by calculating the
ring space without calling ring_dist.

Also ring_dist is only used by ring_space, so this patch
removes it when it is no longer used.

Signed-off-by: Yunsheng Lin <linyunsheng@...wei.com>
Signed-off-by: Peng Li <lipeng321@...wei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@...wei.com>
---
 drivers/net/ethernet/hisilicon/hns3/hns3_enet.h | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
index 75669cd..025d0f7 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.h
@@ -577,18 +577,13 @@ union l4_hdr_info {
 	unsigned char *hdr;
 };
 
-/* the distance between [begin, end) in a ring buffer
- * note: there is a unuse slot between the begin and the end
- */
-static inline int ring_dist(struct hns3_enet_ring *ring, int begin, int end)
-{
-	return (end - begin + ring->desc_num) % ring->desc_num;
-}
-
 static inline int ring_space(struct hns3_enet_ring *ring)
 {
-	return ring->desc_num -
-		ring_dist(ring, ring->next_to_clean, ring->next_to_use) - 1;
+	int begin = ring->next_to_clean;
+	int end = ring->next_to_use;
+
+	return ((end >= begin) ? (ring->desc_num - end + begin) :
+			(begin - end)) - 1;
 }
 
 static inline int is_ring_empty(struct hns3_enet_ring *ring)
-- 
2.7.4