On 23/08/2021 20.01, Jakub Kicinski wrote:
Both struct netdev_rx_queue and struct xdp_rxq_info are cacheline
aligned. This causes extra padding before and after the xdp_rxq
member. Move the member upfront, so that it's naturally aligned.
Before:
/* size: 256, cachelines: 4, members: 6 */
/* sum members: 160, holes: 1, sum holes: 40 */
/* padding: 56 */
/* paddings: 1, sum paddings: 36 */
/* forced alignments: 1, forced holes: 1, sum forced holes: 40 */
After:
/* size: 192, cachelines: 3, members: 6 */
/* padding: 32 */
/* paddings: 1, sum paddings: 36 */
/* forced alignments: 1 */
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
---
include/linux/netdevice.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
LGTM
Acked-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9579942ac2fd..514ec3a0507c 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -722,13 +722,13 @@ bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, u32 flow_id,
/* This structure contains an instance of an RX queue. */
struct netdev_rx_queue {
+ struct xdp_rxq_info xdp_rxq;
#ifdef CONFIG_RPS
struct rps_map __rcu *rps_map;
struct rps_dev_flow_table __rcu *rps_flow_table;
#endif
struct kobject kobj;
struct net_device *dev;
- struct xdp_rxq_info xdp_rxq;
#ifdef CONFIG_XDP_SOCKETS
struct xsk_buff_pool *pool;
#endif
