From ce7f49ab741591d83e33e56948bac2f12de6e14e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 6 Mar 2024 16:00:31 +0000 Subject: [PATCH] net: move rps_sock_flow_table to net_hotdata rps_sock_flow_table and rps_cpu_mask are used in fast path. Move them 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/20240306160031.874438-19-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/hotdata.h | 4 ++++ include/net/rps.h | 8 +++----- net/core/dev.c | 12 +++--------- net/core/sysctl_net_core.c | 9 ++++++--- 4 files changed, 16 insertions(+), 17 deletions(-) diff --git a/include/net/hotdata.h b/include/net/hotdata.h index b0b847585f7e..003667a1efd6 100644 --- a/include/net/hotdata.h +++ b/include/net/hotdata.h @@ -27,6 +27,10 @@ struct net_hotdata { struct kmem_cache *skbuff_cache; struct kmem_cache *skbuff_fclone_cache; struct kmem_cache *skb_small_head_cache; +#ifdef CONFIG_RPS + struct rps_sock_flow_table __rcu *rps_sock_flow_table; + u32 rps_cpu_mask; +#endif int gro_normal_batch; int netdev_budget; int netdev_budget_usecs; diff --git a/include/net/rps.h b/include/net/rps.h index 6081d817d245..7660243e905b 100644 --- a/include/net/rps.h +++ b/include/net/rps.h @@ -5,6 +5,7 @@ #include #include #include +#include #ifdef CONFIG_RPS @@ -64,14 +65,11 @@ struct rps_sock_flow_table { #define RPS_NO_CPU 0xffff -extern u32 rps_cpu_mask; -extern struct rps_sock_flow_table __rcu *rps_sock_flow_table; - static inline void rps_record_sock_flow(struct rps_sock_flow_table *table, u32 hash) { unsigned int index = hash & table->mask; - u32 val = hash & ~rps_cpu_mask; + u32 val = hash & ~net_hotdata.rps_cpu_mask; /* We only give a hint, preemption can change CPU under us */ val |= raw_smp_processor_id(); @@ -93,7 +91,7 @@ static inline void sock_rps_record_flow_hash(__u32 hash) if (!hash) return; rcu_read_lock(); - sock_flow_table = rcu_dereference(rps_sock_flow_table); + sock_flow_table = rcu_dereference(net_hotdata.rps_sock_flow_table); if (sock_flow_table) rps_record_sock_flow(sock_flow_table, hash); rcu_read_unlock(); diff --git a/net/core/dev.c b/net/core/dev.c index bcf49b0393d2..0766a245816b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4450,12 +4450,6 @@ static inline void ____napi_schedule(struct softnet_data *sd, #ifdef CONFIG_RPS -/* One global table that all flow-based protocols share. */ -struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly; -EXPORT_SYMBOL(rps_sock_flow_table); -u32 rps_cpu_mask __read_mostly; -EXPORT_SYMBOL(rps_cpu_mask); - struct static_key_false rps_needed __read_mostly; EXPORT_SYMBOL(rps_needed); struct static_key_false rfs_needed __read_mostly; @@ -4547,7 +4541,7 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, if (!hash) goto done; - sock_flow_table = rcu_dereference(rps_sock_flow_table); + sock_flow_table = rcu_dereference(net_hotdata.rps_sock_flow_table); if (flow_table && sock_flow_table) { struct rps_dev_flow *rflow; u32 next_cpu; @@ -4557,10 +4551,10 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow(). */ ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]); - if ((ident ^ hash) & ~rps_cpu_mask) + if ((ident ^ hash) & ~net_hotdata.rps_cpu_mask) goto try_rps; - next_cpu = ident & rps_cpu_mask; + next_cpu = ident & net_hotdata.rps_cpu_mask; /* OK, now we know there is a match, * we can look at the local (per receive queue) flow table diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index 4b93e27404e8..6973dda3abda 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -140,7 +140,8 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write, mutex_lock(&sock_flow_mutex); - orig_sock_table = rcu_dereference_protected(rps_sock_flow_table, + orig_sock_table = rcu_dereference_protected( + net_hotdata.rps_sock_flow_table, lockdep_is_held(&sock_flow_mutex)); size = orig_size = orig_sock_table ? orig_sock_table->mask + 1 : 0; @@ -161,7 +162,8 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write, mutex_unlock(&sock_flow_mutex); return -ENOMEM; } - rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1; + net_hotdata.rps_cpu_mask = + roundup_pow_of_two(nr_cpu_ids) - 1; sock_table->mask = size - 1; } else sock_table = orig_sock_table; @@ -172,7 +174,8 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write, sock_table = NULL; if (sock_table != orig_sock_table) { - rcu_assign_pointer(rps_sock_flow_table, sock_table); + rcu_assign_pointer(net_hotdata.rps_sock_flow_table, + sock_table); if (sock_table) { static_branch_inc(&rps_needed); static_branch_inc(&rfs_needed);