diff options
author | Coco Li <lixiaoyan@google.com> | 2023-12-04 20:12:30 +0000 |
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committer | Jakub Kicinski <kuba@kernel.org> | 2023-12-05 20:16:05 -0800 |
commit | 43a71cd66b9c0a4af3d15d8644359fde35bdbed0 (patch) | |
tree | b41dbe519b999a23ed3bd12fdc0e97d61b4ef744 /include/linux/netdevice.h | |
parent | 5aa00e9e41f2742223fe4ca89d94410d2477118d (diff) | |
download | linux-43a71cd66b9c0a4af3d15d8644359fde35bdbed0.tar.gz |
net-device: reorganize net_device fast path variables
Reorganize fast path variables on tx-txrx-rx order
Fastpath variables end after npinfo.
Below data generated with pahole on x86 architecture.
Fast path variables span cache lines before change: 12
Fast path variables span cache lines after change: 4
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20231204201232.520025-2-lixiaoyan@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux/netdevice.h')
-rw-r--r-- | include/linux/netdevice.h | 117 |
1 files changed, 64 insertions, 53 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 5551177e024e02..cb96aad6a6ee37 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2097,6 +2097,70 @@ enum netdev_stat_type { */ struct net_device { + /* Cacheline organization can be found documented in + * Documentation/networking/net_cachelines/net_device.rst. + * Please update the document when adding new fields. + */ + + /* TX read-mostly hotpath */ + __cacheline_group_begin(net_device_read_tx); + unsigned long long priv_flags; + const struct net_device_ops *netdev_ops; + const struct header_ops *header_ops; + struct netdev_queue *_tx; + unsigned int real_num_tx_queues; + unsigned int gso_max_size; + unsigned int gso_ipv4_max_size; + u16 gso_max_segs; + s16 num_tc; + /* Note : dev->mtu is often read without holding a lock. + * Writers usually hold RTNL. + * It is recommended to use READ_ONCE() to annotate the reads, + * and to use WRITE_ONCE() to annotate the writes. + */ + unsigned int mtu; + unsigned short needed_headroom; + struct netdev_tc_txq tc_to_txq[TC_MAX_QUEUE]; +#ifdef CONFIG_XPS + struct xps_dev_maps __rcu *xps_maps[XPS_MAPS_MAX]; +#endif +#ifdef CONFIG_NETFILTER_EGRESS + struct nf_hook_entries __rcu *nf_hooks_egress; +#endif +#ifdef CONFIG_NET_XGRESS + struct bpf_mprog_entry __rcu *tcx_egress; +#endif + __cacheline_group_end(net_device_read_tx); + + /* TXRX read-mostly hotpath */ + __cacheline_group_begin(net_device_read_txrx); + unsigned int flags; + unsigned short hard_header_len; + netdev_features_t features; + struct inet6_dev __rcu *ip6_ptr; + __cacheline_group_end(net_device_read_txrx); + + /* RX read-mostly hotpath */ + __cacheline_group_begin(net_device_read_rx); + struct list_head ptype_specific; + int ifindex; + unsigned int real_num_rx_queues; + struct netdev_rx_queue *_rx; + unsigned long gro_flush_timeout; + int napi_defer_hard_irqs; + unsigned int gro_max_size; + unsigned int gro_ipv4_max_size; + rx_handler_func_t __rcu *rx_handler; + void __rcu *rx_handler_data; + possible_net_t nd_net; +#ifdef CONFIG_NETPOLL + struct netpoll_info __rcu *npinfo; +#endif +#ifdef CONFIG_NET_XGRESS + struct bpf_mprog_entry __rcu *tcx_ingress; +#endif + __cacheline_group_end(net_device_read_rx); + char name[IFNAMSIZ]; struct netdev_name_node *name_node; struct dev_ifalias __rcu *ifalias; @@ -2121,7 +2185,6 @@ struct net_device { struct list_head unreg_list; struct list_head close_list; struct list_head ptype_all; - struct list_head ptype_specific; struct { struct list_head upper; @@ -2129,26 +2192,13 @@ struct net_device { } adj_list; /* Read-mostly cache-line for fast-path access */ - unsigned int flags; xdp_features_t xdp_features; - unsigned long long priv_flags; - const struct net_device_ops *netdev_ops; const struct xdp_metadata_ops *xdp_metadata_ops; const struct xsk_tx_metadata_ops *xsk_tx_metadata_ops; - int ifindex; unsigned short gflags; - unsigned short hard_header_len; - /* Note : dev->mtu is often read without holding a lock. - * Writers usually hold RTNL. - * It is recommended to use READ_ONCE() to annotate the reads, - * and to use WRITE_ONCE() to annotate the writes. - */ - unsigned int mtu; - unsigned short needed_headroom; unsigned short needed_tailroom; - netdev_features_t features; netdev_features_t hw_features; netdev_features_t wanted_features; netdev_features_t vlan_features; @@ -2192,8 +2242,6 @@ struct net_device { const struct tlsdev_ops *tlsdev_ops; #endif - const struct header_ops *header_ops; - unsigned char operstate; unsigned char link_mode; @@ -2234,9 +2282,7 @@ struct net_device { /* Protocol-specific pointers */ - struct in_device __rcu *ip_ptr; - struct inet6_dev __rcu *ip6_ptr; #if IS_ENABLED(CONFIG_VLAN_8021Q) struct vlan_info __rcu *vlan_info; #endif @@ -2271,26 +2317,14 @@ struct net_device { /* Interface address info used in eth_type_trans() */ const unsigned char *dev_addr; - struct netdev_rx_queue *_rx; unsigned int num_rx_queues; - unsigned int real_num_rx_queues; - struct bpf_prog __rcu *xdp_prog; - unsigned long gro_flush_timeout; - int napi_defer_hard_irqs; #define GRO_LEGACY_MAX_SIZE 65536u /* TCP minimal MSS is 8 (TCP_MIN_GSO_SIZE), * and shinfo->gso_segs is a 16bit field. */ #define GRO_MAX_SIZE (8 * 65535u) - unsigned int gro_max_size; - unsigned int gro_ipv4_max_size; unsigned int xdp_zc_max_segs; - rx_handler_func_t __rcu *rx_handler; - void __rcu *rx_handler_data; -#ifdef CONFIG_NET_XGRESS - struct bpf_mprog_entry __rcu *tcx_ingress; -#endif struct netdev_queue __rcu *ingress_queue; #ifdef CONFIG_NETFILTER_INGRESS struct nf_hook_entries __rcu *nf_hooks_ingress; @@ -2305,25 +2339,13 @@ struct net_device { /* * Cache lines mostly used on transmit path */ - struct netdev_queue *_tx ____cacheline_aligned_in_smp; unsigned int num_tx_queues; - unsigned int real_num_tx_queues; struct Qdisc __rcu *qdisc; unsigned int tx_queue_len; spinlock_t tx_global_lock; struct xdp_dev_bulk_queue __percpu *xdp_bulkq; -#ifdef CONFIG_XPS - struct xps_dev_maps __rcu *xps_maps[XPS_MAPS_MAX]; -#endif -#ifdef CONFIG_NET_XGRESS - struct bpf_mprog_entry __rcu *tcx_egress; -#endif -#ifdef CONFIG_NETFILTER_EGRESS - struct nf_hook_entries __rcu *nf_hooks_egress; -#endif - #ifdef CONFIG_NET_SCHED DECLARE_HASHTABLE (qdisc_hash, 4); #endif @@ -2362,12 +2384,6 @@ struct net_device { bool needs_free_netdev; void (*priv_destructor)(struct net_device *dev); -#ifdef CONFIG_NETPOLL - struct netpoll_info __rcu *npinfo; -#endif - - possible_net_t nd_net; - /* mid-layer private */ void *ml_priv; enum netdev_ml_priv_type ml_priv_type; @@ -2402,20 +2418,15 @@ struct net_device { */ #define GSO_MAX_SIZE (8 * GSO_MAX_SEGS) - unsigned int gso_max_size; #define TSO_LEGACY_MAX_SIZE 65536 #define TSO_MAX_SIZE UINT_MAX unsigned int tso_max_size; - u16 gso_max_segs; #define TSO_MAX_SEGS U16_MAX u16 tso_max_segs; - unsigned int gso_ipv4_max_size; #ifdef CONFIG_DCB const struct dcbnl_rtnl_ops *dcbnl_ops; #endif - s16 num_tc; - struct netdev_tc_txq tc_to_txq[TC_MAX_QUEUE]; u8 prio_tc_map[TC_BITMASK + 1]; #if IS_ENABLED(CONFIG_FCOE) |