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2024-03-19net: move dev->state into net_device_read_txrx groupEric Dumazet1-1/+1
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>
2024-02-28Documentations: correct net_cachelines title for struct inet_sockHaiyue Wang1-3/+3
The fast path usage breakdown describes the detail for 'inet_sock', fix the markup title. Signed-off-by: Haiyue Wang <haiyue.wang@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-12net-device: move lstats in net_device_read_txrxEric Dumazet1-2/+2
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>
2024-02-12tcp: move tp->tcp_usec_ts to tcp_sock_read_txrx groupEric Dumazet1-1/+1
tp->tcp_usec_ts is a read mostly field, used in rx and tx fast paths. Fixes: d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: Wei Wang <weiwan@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-12tcp: move tp->scaling_ratio to tcp_sock_read_txrx groupEric Dumazet1-1/+1
tp->scaling_ratio is a read mostly field, used in rx and tx fast paths. Fixes: d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Coco Li <lixiaoyan@google.com> Cc: Wei Wang <weiwan@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-01-03net-device: move xdp_prog to net_device_read_rxEric Dumazet1-1/+1
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>
2024-01-02net-device: move gso_partial_features to net_device_read_txEric Dumazet1-1/+1
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>
2023-12-05Documentations: fix net_cachelines documentation build warningCoco Li7-0/+7
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>
2023-12-02Documentations: Analyze heavily used Networking related structsCoco Li7-0/+731
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>
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