kevin/linux
1
Fork 0
Code
master
linux/Documentation/networking/net_cachelines/net_device.rst

186 lines
19 KiB
ReStructuredText
Raw Permalink Normal View History

Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
.. SPDX-License-Identifier: GPL-2.0
.. Copyright (C) 2023 Google LLC
Documentations: fix net_cachelines documentation build warning Original errors: Documentation/networking/net_cachelines/index.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/inet_connection_sock.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/inet_sock.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/net_device.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/netns_ipv4_sysctl.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/snmp.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Documentation/networking/net_cachelines/tcp_sock.rst:3: WARNING: Explicit markup ends without a blank line; unexpected unindent. Fixes: 14006f1d8fa2 ("Documentations: Analyze heavily used Networking related structs") Signed-off-by: Coco Li <lixiaoyan@google.com> Link: https://lore.kernel.org/r/20231204220728.746134-1-lixiaoyan@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-04 15:07:28 -07:00
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
===========================================
net_device struct fast path usage breakdown
===========================================
Type Name fastpath_tx_access fastpath_rx_access Comments
..struct ..net_device
netdevice: convert private flags > BIT(31) to bitfields Make dev->priv_flags `u32` back and define bits higher than 31 as bitfield booleans as per Jakub's suggestion. This simplifies code which accesses these bits with no optimization loss (testb both before/after), allows to not extend &netdev_priv_flags each time, but also scales better as bits > 63 in the future would only add a new u64 to the structure with no complications, comparing to that extending ::priv_flags would require converting it to a bitmap. Note that I picked `unsigned long :1` to not lose any potential optimizations comparing to `bool :1` etc. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29 05:33:36 -07:00
unsigned_long:32 priv_flags read_mostly - __dev_queue_xmit(tx)
netdev_features: convert NETIF_F_LLTX to dev->lltx NETIF_F_LLTX can't be changed via Ethtool and is not a feature, rather an attribute, very similar to IFF_NO_QUEUE (and hot). Free one netdev_features_t bit and make it a "hot" private flag. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29 05:33:37 -07:00
unsigned_long:1 lltx read_mostly - HARD_TX_LOCK,HARD_TX_TRYLOCK,HARD_TX_UNLOCK(tx)
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
char name[16] - -
struct_netdev_name_node* name_node
struct_dev_ifalias* ifalias
unsigned_long mem_end
unsigned_long mem_start
unsigned_long base_addr
net: move dev->state into net_device_read_txrx group dev->state can be read in rx and tx fast paths. netif_running() which needs dev->state is called from - enqueue_to_backlog() [RX path] - __dev_direct_xmit() [TX path] Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240314200845.3050179-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-03-14 13:08:45 -07:00
unsigned_long state read_mostly read_mostly netif_running(dev)
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
struct_list_head dev_list
struct_list_head napi_list
struct_list_head unreg_list
struct_list_head close_list
struct_list_head ptype_all read_mostly - dev_nit_active(tx)
struct_list_head ptype_specific read_mostly deliver_ptype_list_skb/__netif_receive_skb_core(rx)
struct adj_list
unsigned_int flags read_mostly read_mostly __dev_queue_xmit,__dev_xmit_skb,ip6_output,__ip6_finish_output(tx);ip6_rcv_core(rx)
xdp_features_t xdp_features
struct_net_device_ops* netdev_ops read_mostly - netdev_core_pick_tx,netdev_start_xmit(tx)
struct_xdp_metadata_ops* xdp_metadata_ops
int ifindex - read_mostly ip6_rcv_core
unsigned_short gflags
unsigned_short hard_header_len read_mostly read_mostly ip6_xmit(tx);gro_list_prepare(rx)
unsigned_int mtu read_mostly - ip_finish_output2
unsigned_short needed_headroom read_mostly - LL_RESERVED_SPACE/ip_finish_output2
unsigned_short needed_tailroom
netdev_features_t features read_mostly read_mostly HARD_TX_LOCK,netif_skb_features,sk_setup_caps(tx);netif_elide_gro(rx)
netdev_features_t hw_features
netdev_features_t wanted_features
netdev_features_t vlan_features
netdev_features_t hw_enc_features - - netif_skb_features
netdev_features_t mpls_features
net-device: move gso_partial_features to net_device_read_tx dev->gso_partial_features is read from tx fast path for GSO packets. Move it to appropriate section to avoid a cache line miss. Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: David Ahern <dsahern@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-21 07:07:47 -07:00
netdev_features_t gso_partial_features read_mostly gso_features_check
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
unsigned_int min_mtu
unsigned_int max_mtu
unsigned_short type
unsigned_char min_header_len
unsigned_char name_assign_type
int group
struct_net_device_stats stats
struct_net_device_core_stats* core_stats
atomic_t carrier_up_count
atomic_t carrier_down_count
struct_iw_handler_def* wireless_handlers
struct_iw_public_data* wireless_data
struct_ethtool_ops* ethtool_ops
struct_l3mdev_ops* l3mdev_ops
struct_ndisc_ops* ndisc_ops
struct_xfrmdev_ops* xfrmdev_ops
struct_tlsdev_ops* tlsdev_ops
struct_header_ops* header_ops read_mostly - ip_finish_output2,ip6_finish_output2(tx)
unsigned_char operstate
unsigned_char link_mode
unsigned_char if_port
unsigned_char dma
unsigned_char perm_addr[32]
unsigned_char addr_assign_type
unsigned_char addr_len
unsigned_char upper_level
unsigned_char lower_level
unsigned_short neigh_priv_len
unsigned_short padded
unsigned_short dev_id
unsigned_short dev_port
spinlock_t addr_list_lock
int irq
struct_netdev_hw_addr_list uc
struct_netdev_hw_addr_list mc
struct_netdev_hw_addr_list dev_addrs
struct_kset* queues_kset
struct_list_head unlink_list
unsigned_int promiscuity
unsigned_int allmulti
bool uc_promisc
unsigned_char nested_level
struct_in_device* ip_ptr read_mostly read_mostly __in_dev_get
struct_inet6_dev* ip6_ptr read_mostly read_mostly __in6_dev_get
struct_vlan_info* vlan_info
struct_dsa_port* dsa_ptr
struct_tipc_bearer* tipc_ptr
void* atalk_ptr
void* ax25_ptr
struct_wireless_dev* ieee80211_ptr
struct_wpan_dev* ieee802154_ptr
struct_mpls_dev* mpls_ptr
struct_mctp_dev* mctp_ptr
unsigned_char* dev_addr
struct_netdev_queue* _rx read_mostly - netdev_get_rx_queue(rx)
unsigned_int num_rx_queues
unsigned_int real_num_rx_queues - read_mostly get_rps_cpu
net-device: move xdp_prog to net_device_read_rx xdp_prog is used in receive path, both from XDP enabled drivers and from netif_elide_gro(). This patch also removes two 4-bytes holes. Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: Simon Horman <horms@kernel.org> Link: https://lore.kernel.org/r/20240102162220.750823-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-02 09:22:20 -07:00
struct_bpf_prog* xdp_prog - read_mostly netif_elide_gro()
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
unsigned_long gro_flush_timeout - read_mostly napi_complete_done
net: napi: Prevent overflow of napi_defer_hard_irqs In commit 6f8b12d661d0 ("net: napi: add hard irqs deferral feature") napi_defer_irqs was added to net_device and napi_defer_irqs_count was added to napi_struct, both as type int. This value never goes below zero, so there is not reason for it to be a signed int. Change the type for both from int to u32, and add an overflow check to sysfs to limit the value to S32_MAX. The limit of S32_MAX was chosen because the practical limit before this patch was S32_MAX (anything larger was an overflow) and thus there are no behavioral changes introduced. If the extra bit is needed in the future, the limit can be raised. Before this patch: $ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs' $ cat /sys/class/net/eth4/napi_defer_hard_irqs -2147483647 After this patch: $ sudo bash -c 'echo 2147483649 > /sys/class/net/eth4/napi_defer_hard_irqs' bash: line 0: echo: write error: Numerical result out of range Similarly, /sys/class/net/XXXXX/tx_queue_len is defined as unsigned: include/linux/netdevice.h: unsigned int tx_queue_len; And has an overflow check: dev_change_tx_queue_len(..., unsigned long new_len): if (new_len != (unsigned int)new_len) return -ERANGE; Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Joe Damato <jdamato@fastly.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20240904153431.307932-1-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-09-04 08:34:30 -07:00
u32 napi_defer_hard_irqs - read_mostly napi_complete_done
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
unsigned_int gro_max_size - read_mostly skb_gro_receive
unsigned_int gro_ipv4_max_size - read_mostly skb_gro_receive
rx_handler_func_t* rx_handler read_mostly - __netif_receive_skb_core
void* rx_handler_data read_mostly -
struct_netdev_queue* ingress_queue read_mostly -
struct_bpf_mprog_entry tcx_ingress - read_mostly sch_handle_ingress
struct_nf_hook_entries* nf_hooks_ingress
unsigned_char broadcast[32]
struct_cpu_rmap* rx_cpu_rmap
struct_hlist_node index_hlist
struct_netdev_queue* _tx read_mostly - netdev_get_tx_queue(tx)
unsigned_int num_tx_queues - -
unsigned_int real_num_tx_queues read_mostly - skb_tx_hash,netdev_core_pick_tx(tx)
unsigned_int tx_queue_len
spinlock_t tx_global_lock
struct_xdp_dev_bulk_queue__percpu* xdp_bulkq
struct_xps_dev_maps* xps_maps[2] read_mostly - __netif_set_xps_queue
struct_bpf_mprog_entry tcx_egress read_mostly - sch_handle_egress
struct_nf_hook_entries* nf_hooks_egress read_mostly -
struct_hlist_head qdisc_hash[16]
struct_timer_list watchdog_timer
int watchdog_timeo
u32 proto_down_reason
struct_list_head todo_list
int__percpu* pcpu_refcnt
refcount_t dev_refcnt
struct_ref_tracker_dir refcnt_tracker
struct_list_head link_watch_list
enum:8 reg_state
bool dismantle
enum:16 rtnl_link_state
bool needs_free_netdev
void*priv_destructor struct_net_device
struct_netpoll_info* npinfo - read_mostly napi_poll/napi_poll_lock
possible_net_t nd_net - read_mostly (dev_net)napi_busy_loop,tcp_v(4/6)_rcv,ip(v6)_rcv,ip(6)_input,ip(6)_input_finish
void* ml_priv
enum_netdev_ml_priv_type ml_priv_type
net-device: move lstats in net_device_read_txrx dev->lstats is notably used from loopback ndo_start_xmit() and other virtual drivers. Per cpu stats updates are dirtying per-cpu data, but the pointer itself is read-only. Fixes: 43a71cd66b9c ("net-device: reorganize net_device fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: Simon Horman <horms@kernel.org> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-08 07:43:23 -07:00
struct_pcpu_lstats__percpu* lstats read_mostly dev_lstats_add()
struct_pcpu_sw_netstats__percpu* tstats read_mostly dev_sw_netstats_tx_add()
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
struct_pcpu_dstats__percpu* dstats
struct_garp_port* garp_port
struct_mrp_port* mrp_port
struct_dm_hw_stat_delta* dm_private
struct_device dev - -
struct_attribute_group* sysfs_groups[4]
struct_attribute_group* sysfs_rx_queue_group
struct_rtnl_link_ops* rtnl_link_ops
unsigned_int gso_max_size read_mostly - sk_dst_gso_max_size
unsigned_int tso_max_size
u16 gso_max_segs read_mostly - gso_max_segs
u16 tso_max_segs
unsigned_int gso_ipv4_max_size read_mostly - sk_dst_gso_max_size
struct_dcbnl_rtnl_ops* dcbnl_ops
s16 num_tc read_mostly - skb_tx_hash
struct_netdev_tc_txq tc_to_txq[16] read_mostly - skb_tx_hash
u8 prio_tc_map[16]
unsigned_int fcoe_ddp_xid
struct_netprio_map* priomap
struct_phy_device* phydev
struct_sfp_bus* sfp_bus
struct_lock_class_key* qdisc_tx_busylock
bool proto_down
unsigned:1 wol_enabled
unsigned:1 threaded - - napi_poll(napi_enable,dev_set_threaded)
netdevice: convert private flags > BIT(31) to bitfields Make dev->priv_flags `u32` back and define bits higher than 31 as bitfield booleans as per Jakub's suggestion. This simplifies code which accesses these bits with no optimization loss (testb both before/after), allows to not extend &netdev_priv_flags each time, but also scales better as bits > 63 in the future would only add a new u64 to the structure with no complications, comparing to that extending ::priv_flags would require converting it to a bitmap. Note that I picked `unsigned long :1` to not lose any potential optimizations comparing to `bool :1` etc. Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29 05:33:36 -07:00
unsigned_long:1 see_all_hwtstamp_requests
unsigned_long:1 change_proto_down
netdev_features: convert NETIF_F_NETNS_LOCAL to dev->netns_local "Interface can't change network namespaces" is rather an attribute, not a feature, and it can't be changed via Ethtool. Make it a "cold" private flag instead of a netdev_feature and free one more bit. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29 05:33:38 -07:00
unsigned_long:1 netns_local
netdev_features: convert NETIF_F_FCOE_MTU to dev->fcoe_mtu Ability to handle maximum FCoE frames of 2158 bytes can never be changed and thus more of an attribute, not a toggleable feature. Move it from netdev_features_t to "cold" priv flags (bitfield bool) and free yet another feature bit. Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-08-29 05:33:39 -07:00
unsigned_long:1 fcoe_mtu
Documentations: Analyze heavily used Networking related structs Analyzed a few structs in the networking stack by looking at variables within them that are used in the TCP/IP fast path. Fast path is defined as TCP path where data is transferred from sender to receiver unidirectionally. It doesn't include phases other than TCP_ESTABLISHED, nor does it look at error paths. We hope to re-organizing variables that span many cachelines whose fast path variables are also spread out, and this document can help future developers keep networking fast path cachelines small. Optimized_cacheline field is computed as (Fastpath_Bytes/L3_cacheline_size_x86), and not the actual organized results (see patches to come for these). Investigation is done on 6.5 Name Struct_Cachelines Cur_fastpath_cache Fastpath_Bytes Optimized_cacheline tcp_sock 42 (2664 Bytes) 12 396 8 net_device 39 (2240 bytes) 12 234 4 inet_sock 15 (960 bytes) 14 922 14 Inet_connection_sock 22 (1368 bytes) 18 1166 18 Netns_ipv4 (sysctls) 12 (768 bytes) 4 77 2 linux_mib 16 (1060) 6 104 2 Note how there isn't much improvement space for inet_sock and Inet_connection_sock because sk and icsk_inet respectively takes up so much of the struct that rest of the variables become a small portion of the struct size. So, we decided to reorganize tcp_sock, net_device, netns_ipv4 Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Coco Li <lixiaoyan@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2023-11-29 00:27:52 -07:00
struct_list_head net_notifier_list
struct_macsec_ops* macsec_ops
struct_udp_tunnel_nic_info* udp_tunnel_nic_info
struct_udp_tunnel_nic* udp_tunnel_nic
unsigned_int xdp_zc_max_segs
struct_bpf_xdp_entity xdp_state[3]
u8 dev_addr_shadow[32]
netdevice_tracker linkwatch_dev_tracker
netdevice_tracker watchdog_dev_tracker
netdevice_tracker dev_registered_tracker
struct_rtnl_hw_stats64* offload_xstats_l3
struct_devlink_port* devlink_port
struct_dpll_pin* dpll_pin
Documentation: Add missing fields to net_cachelines Two fields, page_pools and *irq_moder, were added to struct net_device in commit 083772c9f972 ("net: page_pool: record pools per netdev") and commit f750dfe825b9 ("ethtool: provide customized dim profile management"), respectively. Add both to the net_cachelines documentation, as well. Signed-off-by: Joe Damato <jdamato@fastly.com> Link: https://patch.msgid.link/20240829155742.366584-1-jdamato@fastly.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-29 08:57:42 -07:00
struct hlist_head page_pools
struct dim_irq_moder* irq_moder
Copy Permalink