From accdd51dc74ff65b7b7be1961b11723d228fbbbd Mon Sep 17 00:00:00 2001 From: Philo Lu Date: Thu, 14 Nov 2024 18:52:04 +0800 Subject: net/udp: Add a new struct for hash2 slot Preparing for udp 4-tuple hash (uhash4 for short). To implement uhash4 without cache line missing when lookup, hslot2 is used to record the number of hashed sockets in hslot4. Thus adding a new struct udp_hslot_main with field hash4_cnt, which is used by hash2. The new struct is used to avoid doubling the size of udp_hslot. Before uhash4 lookup, firstly checking hash4_cnt to see if there are hashed sks in hslot4. Because hslot2 is always used in lookup, there is no cache line miss. Related helpers are updated, and use the helpers as possible. uhash4 is implemented in following patches. Signed-off-by: Philo Lu Acked-by: Willem de Bruijn Acked-by: Paolo Abeni Signed-off-by: David S. Miller --- include/net/udp.h | 38 ++++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/net/udp.h b/include/net/udp.h index 61222545ab1c..62a7207e65f2 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -50,7 +50,7 @@ struct udp_skb_cb { #define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb)) /** - * struct udp_hslot - UDP hash slot + * struct udp_hslot - UDP hash slot used by udp_table.hash * * @head: head of list of sockets * @count: number of sockets in 'head' list @@ -60,7 +60,22 @@ struct udp_hslot { struct hlist_head head; int count; spinlock_t lock; -} __attribute__((aligned(2 * sizeof(long)))); +} __aligned(2 * sizeof(long)); + +/** + * struct udp_hslot_main - UDP hash slot used by udp_table.hash2 + * + * @hslot: basic hash slot + * @hash4_cnt: number of sockets in hslot4 of the same + * (local port, local address) + */ +struct udp_hslot_main { + struct udp_hslot hslot; /* must be the first member */ +#if !IS_ENABLED(CONFIG_BASE_SMALL) + u32 hash4_cnt; +#endif +} __aligned(2 * sizeof(long)); +#define UDP_HSLOT_MAIN(__hslot) ((struct udp_hslot_main *)(__hslot)) /** * struct udp_table - UDP table @@ -72,7 +87,7 @@ struct udp_hslot { */ struct udp_table { struct udp_hslot *hash; - struct udp_hslot *hash2; + struct udp_hslot_main *hash2; unsigned int mask; unsigned int log; }; @@ -84,6 +99,7 @@ static inline struct udp_hslot *udp_hashslot(struct udp_table *table, { return &table->hash[udp_hashfn(net, num, table->mask)]; } + /* * For secondary hash, net_hash_mix() is performed before calling * udp_hashslot2(), this explains difference with udp_hashslot() @@ -91,8 +107,22 @@ static inline struct udp_hslot *udp_hashslot(struct udp_table *table, static inline struct udp_hslot *udp_hashslot2(struct udp_table *table, unsigned int hash) { - return &table->hash2[hash & table->mask]; + return &table->hash2[hash & table->mask].hslot; +} + +#if IS_ENABLED(CONFIG_BASE_SMALL) +static inline void udp_table_hash4_init(struct udp_table *table) +{ +} +#else /* !CONFIG_BASE_SMALL */ + +/* Must be called with table->hash2 initialized */ +static inline void udp_table_hash4_init(struct udp_table *table) +{ + for (int i = 0; i <= table->mask; i++) + table->hash2[i].hash4_cnt = 0; } +#endif /* CONFIG_BASE_SMALL */ extern struct proto udp_prot; -- cgit v1.2.3