kernel/linux.git/Documentation/admin-guide/sysctl/net.rst, branch v6.6.133

net: make SK_MEMORY_PCPU_RESERV tunable

2024-05-02T14:32:36+00:00

[ Upstream commit 12a686c2e761f1f1f6e6e2117a9ab9c6de2ac8a7 ] This patch adds /proc/sys/net/core/mem_pcpu_rsv sysctl file, to make SK_MEMORY_PCPU_RESERV tunable. Commit 3cd3399dd7a8 ("net: implement per-cpu reserves for memory_allocated") introduced per-cpu forward alloc cache: "Implement a per-cpu cache of +1/-1 MB, to reduce number of changes to sk->sk_prot->memory_allocated, which would otherwise be cause of false sharing." sk_prot->memory_allocated points to global atomic variable: atomic_long_t tcp_memory_allocated ____cacheline_aligned_in_smp; If increasing the per-cpu cache size from 1MB to e.g. 16MB, changes to sk->sk_prot->memory_allocated can be further reduced. Performance may be improved on system with many cores. Signed-off-by: Adam Li Reviewed-by: Christoph Lameter (Ampere) Signed-off-by: David S. Miller Stable-dep-of: 3584718cf2ec ("net: fix sk_memory_allocated_{add|sub} vs softirqs") Signed-off-by: Sasha Levin

Documentation: net: net.core.txrehash is not specific to listening sockets

2023-05-25T11:20:45+00:00

The net.core.txrehash documentation mentions this knob is for listening sockets only, while sk_rethink_txhash can be called on SYN and RTO retransmits on all TCP sockets. Remove the listening socket part. Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Signed-off-by: Paolo Abeni

net: introduce default_rps_mask netns attribute

2023-02-10T01:45:55+00:00

If RPS is enabled, this allows configuring a default rps mask, which is effective since receive queue creation time. A default RPS mask allows the system admin to ensure proper isolation, avoiding races at network namespace or device creation time. The default RPS mask is initially empty, and can be modified via a newly added sysctl entry. Signed-off-by: Paolo Abeni Reviewed-by: Simon Horman Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski

bpf: Use bpf_capable() instead of CAP_SYS_ADMIN for blinding decision

2022-09-16T20:11:57+00:00

The full CAP_SYS_ADMIN requirement for blinding looks too strict nowadays. These days given unprivileged BPF is disabled by default, the main users for constant blinding coming from unprivileged in particular via cBPF -> eBPF migration (e.g. old-style socket filters). Signed-off-by: Yauheni Kaliuta Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20220831090655.156434-1-ykaliuta@redhat.com Link: https://lore.kernel.org/bpf/20220905090149.61221-1-ykaliuta@redhat.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-08-25T23:07:42+00:00

drivers/net/ethernet/mellanox/mlx5/core/en_fs.c 21234e3a84c7 ("net/mlx5e: Fix use after free in mlx5e_fs_init()") c7eafc5ed068 ("net/mlx5e: Convert ethtool_steering member of flow_steering struct to pointer") https://lore.kernel.org/all/20220825104410.67d4709c@canb.auug.org.au/ https://lore.kernel.org/all/20220823055533.334471-1-saeed@kernel.org/ Signed-off-by: Jakub Kicinski

Documentation: sysctl: align cells in second content column

2022-08-25T01:42:51+00:00

Stephen Rothwell reported htmldocs warning when merging net-next tree: Documentation/admin-guide/sysctl/net.rst:37: WARNING: Malformed table. Text in column margin in table line 4. ========= =================== = ========== ================== Directory Content Directory Content ========= =================== = ========== ================== 802 E802 protocol mptcp Multipath TCP appletalk Appletalk protocol netfilter Network Filter ax25 AX25 netrom NET/ROM bridge Bridging rose X.25 PLP layer core General parameter tipc TIPC ethernet Ethernet protocol unix Unix domain sockets ipv4 IP version 4 x25 X.25 protocol ipv6 IP version 6 ========= =================== = ========== ================== The warning above is caused by cells in second "Content" column of /proc/sys/net subdirectory table which are in column margin. Align these cells against the column header to fix the warning. Link: https://lore.kernel.org/linux-next/20220823134905.57ed08d5@canb.auug.org.au/ Fixes: 1202cdd665315c ("Remove DECnet support from kernel") Reported-by: Stephen Rothwell Signed-off-by: Bagas Sanjaya Link: https://lore.kernel.org/r/20220824035804.204322-1-bagasdotme@gmail.com Signed-off-by: Jakub Kicinski

net: Fix data-races around netdev_max_backlog.

2022-08-24T12:46:57+00:00

While reading netdev_max_backlog, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. While at it, we remove the unnecessary spaces in the doc. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller

Remove DECnet support from kernel

2022-08-22T13:26:30+00:00

DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger Acked-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

Documentation: add a description for net.core.high_order_alloc_disable

2022-07-09T03:15:59+00:00

A description is missing for the net.core.high_order_alloc_disable option in admin-guide/sysctl/net.rst ; add it. The above sysctl option was introduced by commit ce27ec60648d ("net: add high_order_alloc_disable sysctl/static key"). Thanks to Eric for running again the benchmark cited in the above commit, showing this knob is now mostly of historical importance. Signed-off-by: Antoine Tenart Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20220707080245.180525-1-atenart@kernel.org Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2022-05-24T04:19:17+00:00

drivers/net/ethernet/cadence/macb_main.c 5cebb40bc955 ("net: macb: Fix PTP one step sync support") 138badbc21a0 ("net: macb: use NAPI for TX completion path") https://lore.kernel.org/all/20220523111021.31489367@canb.auug.org.au/ net/smc/af_smc.c 75c1edf23b95 ("net/smc: postpone sk_refcnt increment in connect()") 3aba103006bc ("net/smc: align the connect behaviour with TCP") https://lore.kernel.org/all/20220524114408.4bf1af38@canb.auug.org.au/ Signed-off-by: Jakub Kicinski