From 3ab5aee7fe840b5b1b35a8d1ac11c3de5281e611 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 16 Nov 2008 19:40:17 -0800 Subject: net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls RCU was added to UDP lookups, using a fast infrastructure : - sockets kmem_cache use SLAB_DESTROY_BY_RCU and dont pay the price of call_rcu() at freeing time. - hlist_nulls permits to use few memory barriers. This patch uses same infrastructure for TCP/DCCP established and timewait sockets. Thanks to SLAB_DESTROY_BY_RCU, no slowdown for applications using short lived TCP connections. A followup patch, converting rwlocks to spinlocks will even speedup this case. __inet_lookup_established() is pretty fast now we dont have to dirty a contended cache line (read_lock/read_unlock) Only established and timewait hashtable are converted to RCU (bind table and listen table are still using traditional locking) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/inet_hashtables.h | 4 ++-- include/net/inet_timewait_sock.h | 10 +++++----- 2 files changed, 7 insertions(+), 7 deletions(-) (limited to 'include/net') diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h index cb31fbf8ae2a..481896045111 100644 --- a/include/net/inet_hashtables.h +++ b/include/net/inet_hashtables.h @@ -41,8 +41,8 @@ * I'll experiment with dynamic table growth later. */ struct inet_ehash_bucket { - struct hlist_head chain; - struct hlist_head twchain; + struct hlist_nulls_head chain; + struct hlist_nulls_head twchain; }; /* There are a few simple rules, which allow for local port reuse by diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h index 80e4977631b8..4b8ece22b8e9 100644 --- a/include/net/inet_timewait_sock.h +++ b/include/net/inet_timewait_sock.h @@ -110,7 +110,7 @@ struct inet_timewait_sock { #define tw_state __tw_common.skc_state #define tw_reuse __tw_common.skc_reuse #define tw_bound_dev_if __tw_common.skc_bound_dev_if -#define tw_node __tw_common.skc_node +#define tw_node __tw_common.skc_nulls_node #define tw_bind_node __tw_common.skc_bind_node #define tw_refcnt __tw_common.skc_refcnt #define tw_hash __tw_common.skc_hash @@ -137,10 +137,10 @@ struct inet_timewait_sock { struct hlist_node tw_death_node; }; -static inline void inet_twsk_add_node(struct inet_timewait_sock *tw, - struct hlist_head *list) +static inline void inet_twsk_add_node_rcu(struct inet_timewait_sock *tw, + struct hlist_nulls_head *list) { - hlist_add_head(&tw->tw_node, list); + hlist_nulls_add_head_rcu(&tw->tw_node, list); } static inline void inet_twsk_add_bind_node(struct inet_timewait_sock *tw, @@ -175,7 +175,7 @@ static inline int inet_twsk_del_dead_node(struct inet_timewait_sock *tw) } #define inet_twsk_for_each(tw, node, head) \ - hlist_for_each_entry(tw, node, head, tw_node) + hlist_nulls_for_each_entry(tw, node, head, tw_node) #define inet_twsk_for_each_inmate(tw, node, jail) \ hlist_for_each_entry(tw, node, jail, tw_death_node) -- cgit v1.2.3