From 18fd64d2542292713b0322e6815be059bdee440c Mon Sep 17 00:00:00 2001 From: Coco Li Date: Wed, 29 Nov 2023 07:27:54 +0000 Subject: netns-ipv4: reorganize netns_ipv4 fast path variables Reorganize fast path variables on tx-txrx-rx order. Fastpath cacheline ends after sysctl_tcp_rmem. There are only read-only variables here. (write is on the control path and not considered in this case) Below data generated with pahole on x86 architecture. Fast path variables span cache lines before change: 4 Fast path variables span cache lines after change: 2 Suggested-by: Eric Dumazet Reviewed-by: Wei Wang Reviewed-by: David Ahern Signed-off-by: Coco Li Reviewed-by: Eric Dumazet Reviewed-by: Shakeel Butt Signed-off-by: David S. Miller --- net/core/net_namespace.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'net/core/net_namespace.c') diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index f4183c4c1ec8..cb8bcbff9e83 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -1099,11 +1099,56 @@ out: rtnl_set_sk_err(net, RTNLGRP_NSID, err); } +#ifdef CONFIG_NET_NS +static void __init netns_ipv4_struct_check(void) +{ + /* TX readonly hotpath cache lines */ + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_early_retrans); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_tso_win_divisor); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_tso_rtt_log); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_autocorking); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_min_snd_mss); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_notsent_lowat); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_limit_output_bytes); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_min_rtt_wlen); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_tcp_wmem); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_tx, + sysctl_ip_fwd_use_pmtu); + CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_tx, 33); + + /* TXRX readonly hotpath cache lines */ + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_txrx, + sysctl_tcp_moderate_rcvbuf); + CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_txrx, 1); + + /* RX readonly hotpath cache line */ + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx, + sysctl_ip_early_demux); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx, + sysctl_tcp_early_demux); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx, + sysctl_tcp_reordering); + CACHELINE_ASSERT_GROUP_MEMBER(struct netns_ipv4, netns_ipv4_read_rx, + sysctl_tcp_rmem); + CACHELINE_ASSERT_GROUP_SIZE(struct netns_ipv4, netns_ipv4_read_rx, 18); +} +#endif + void __init net_ns_init(void) { struct net_generic *ng; #ifdef CONFIG_NET_NS + netns_ipv4_struct_check(); net_cachep = kmem_cache_create("net_namespace", sizeof(struct net), SMP_CACHE_BYTES, SLAB_PANIC|SLAB_ACCOUNT, NULL); -- cgit