linux/net/core/hotdata.c, branch v6.16

net: introduce per netns packet chains

2025-03-24T20:58:22Z

Currently network taps unbound to any interface are linked in the global ptype_all list, affecting the performance in all the network namespaces. Add per netns ptypes chains, so that in the mentioned case only the netns owning the packet socket(s) is affected. While at that drop the global ptype_all list: no in kernel user registers a tap on "any" type without specifying either the target device or the target namespace (and IMHO doing that would not make any sense). Note that this adds a conditional in the fast path (to check for per netns ptype_specific list) and increases the dataset size by a cacheline (owing the per netns lists). Reviewed-by: Sabrina Dubroca Signed-off-by: Paolo Abeni Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/ae405f98875ee87f8150c460ad162de7e466f8a7.1742494826.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski

net: move sysctl_mem_pcpu_rsv to net_hotdata

2024-05-01T01:46:52Z

sysctl_mem_pcpu_rsv is used in TCP fast path, move it to net_hodata for better cache locality. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240429134025.1233626-6-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move sysctl_skb_defer_max to net_hotdata

2024-05-01T01:46:52Z

sysctl_skb_defer_max is used in TCP fast path, move it to net_hodata. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240429134025.1233626-3-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move sysctl_max_skb_frags to net_hotdata

2024-05-01T01:46:52Z

sysctl_max_skb_frags is used in TCP and MPTCP fast paths, move it to net_hodata for better cache locality. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240429134025.1233626-2-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move dev_rx_weight to net_hotdata

2024-03-08T05:12:42Z

dev_rx_weight is read from process_backlog(). Move it to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-10-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move dev_tx_weight to net_hotdata

2024-03-08T05:12:42Z

dev_tx_weight is used in tx fast path. Move it to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-9-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move netdev_max_backlog to net_hotdata

2024-03-08T05:12:42Z

netdev_max_backlog is used in rx fat path. Move it to net_hodata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-6-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move ptype_all into net_hotdata

2024-03-08T05:12:41Z

ptype_all is used in rx/tx fast paths. Move it to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-5-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move netdev_tstamp_prequeue into net_hotdata

2024-03-08T05:12:41Z

netdev_tstamp_prequeue is used in rx path. Move it to net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-4-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move netdev_budget and netdev_budget to net_hotdata

2024-03-08T05:12:41Z

netdev_budget and netdev_budget are used in rx path (net_rx_action()) Move them into net_hotdata for better cache locality. Signed-off-by: Eric Dumazet Acked-by: Soheil Hassas Yeganeh Reviewed-by: David Ahern Link: https://lore.kernel.org/r/20240306160031.874438-3-edumazet@google.com Signed-off-by: Jakub Kicinski