diff options
Diffstat (limited to 'include/linux/rhashtable.h')
| -rw-r--r-- | include/linux/rhashtable.h | 70 |
1 files changed, 58 insertions, 12 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 05a221ce79a6..08e664b21f5a 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -355,12 +355,25 @@ static inline void rht_unlock(struct bucket_table *tbl, local_irq_restore(flags); } -static inline struct rhash_head *__rht_ptr( - struct rhash_lock_head *p, struct rhash_lock_head __rcu *const *bkt) +enum rht_lookup_freq { + RHT_LOOKUP_NORMAL, + RHT_LOOKUP_LIKELY, +}; + +static __always_inline struct rhash_head *__rht_ptr( + struct rhash_lock_head *p, struct rhash_lock_head __rcu *const *bkt, + const enum rht_lookup_freq freq) { - return (struct rhash_head *) - ((unsigned long)p & ~BIT(0) ?: - (unsigned long)RHT_NULLS_MARKER(bkt)); + unsigned long p_val = (unsigned long)p & ~BIT(0); + + BUILD_BUG_ON(!__builtin_constant_p(freq)); + + if (freq == RHT_LOOKUP_LIKELY) + return (struct rhash_head *) + (likely(p_val) ? p_val : (unsigned long)RHT_NULLS_MARKER(bkt)); + else + return (struct rhash_head *) + (p_val ?: (unsigned long)RHT_NULLS_MARKER(bkt)); } /* @@ -370,10 +383,17 @@ static inline struct rhash_head *__rht_ptr( * rht_ptr_exclusive() dereferences in a context where exclusive * access is guaranteed, such as when destroying the table. */ +static __always_inline struct rhash_head *__rht_ptr_rcu( + struct rhash_lock_head __rcu *const *bkt, + const enum rht_lookup_freq freq) +{ + return __rht_ptr(rcu_dereference_all(*bkt), bkt, freq); +} + static inline struct rhash_head *rht_ptr_rcu( struct rhash_lock_head __rcu *const *bkt) { - return __rht_ptr(rcu_dereference_all(*bkt), bkt); + return __rht_ptr_rcu(bkt, RHT_LOOKUP_NORMAL); } static inline struct rhash_head *rht_ptr( @@ -381,13 +401,15 @@ static inline struct rhash_head *rht_ptr( struct bucket_table *tbl, unsigned int hash) { - return __rht_ptr(rht_dereference_bucket(*bkt, tbl, hash), bkt); + return __rht_ptr(rht_dereference_bucket(*bkt, tbl, hash), bkt, + RHT_LOOKUP_NORMAL); } static inline struct rhash_head *rht_ptr_exclusive( struct rhash_lock_head __rcu *const *bkt) { - return __rht_ptr(rcu_dereference_protected(*bkt, 1), bkt); + return __rht_ptr(rcu_dereference_protected(*bkt, 1), bkt, + RHT_LOOKUP_NORMAL); } static inline void rht_assign_locked(struct rhash_lock_head __rcu **bkt, @@ -588,7 +610,8 @@ static inline int rhashtable_compare(struct rhashtable_compare_arg *arg, /* Internal function, do not use. */ static __always_inline struct rhash_head *__rhashtable_lookup( struct rhashtable *ht, const void *key, - const struct rhashtable_params params) + const struct rhashtable_params params, + const enum rht_lookup_freq freq) { struct rhashtable_compare_arg arg = { .ht = ht, @@ -599,12 +622,13 @@ static __always_inline struct rhash_head *__rhashtable_lookup( struct rhash_head *he; unsigned int hash; + BUILD_BUG_ON(!__builtin_constant_p(freq)); tbl = rht_dereference_rcu(ht->tbl, ht); restart: hash = rht_key_hashfn(ht, tbl, key, params); bkt = rht_bucket(tbl, hash); do { - rht_for_each_rcu_from(he, rht_ptr_rcu(bkt), tbl, hash) { + rht_for_each_rcu_from(he, __rht_ptr_rcu(bkt, freq), tbl, hash) { if (params.obj_cmpfn ? params.obj_cmpfn(&arg, rht_obj(ht, he)) : rhashtable_compare(&arg, rht_obj(ht, he))) @@ -643,11 +667,22 @@ static __always_inline void *rhashtable_lookup( struct rhashtable *ht, const void *key, const struct rhashtable_params params) { - struct rhash_head *he = __rhashtable_lookup(ht, key, params); + struct rhash_head *he = __rhashtable_lookup(ht, key, params, + RHT_LOOKUP_NORMAL); return he ? rht_obj(ht, he) : NULL; } +static __always_inline void *rhashtable_lookup_likely( + struct rhashtable *ht, const void *key, + const struct rhashtable_params params) +{ + struct rhash_head *he = __rhashtable_lookup(ht, key, params, + RHT_LOOKUP_LIKELY); + + return likely(he) ? rht_obj(ht, he) : NULL; +} + /** * rhashtable_lookup_fast - search hash table, without RCU read lock * @ht: hash table @@ -693,11 +728,22 @@ static __always_inline struct rhlist_head *rhltable_lookup( struct rhltable *hlt, const void *key, const struct rhashtable_params params) { - struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params); + struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params, + RHT_LOOKUP_NORMAL); return he ? container_of(he, struct rhlist_head, rhead) : NULL; } +static __always_inline struct rhlist_head *rhltable_lookup_likely( + struct rhltable *hlt, const void *key, + const struct rhashtable_params params) +{ + struct rhash_head *he = __rhashtable_lookup(&hlt->ht, key, params, + RHT_LOOKUP_LIKELY); + + return likely(he) ? container_of(he, struct rhlist_head, rhead) : NULL; +} + /* Internal function, please use rhashtable_insert_fast() instead. This * function returns the existing element already in hashes if there is a clash, * otherwise it returns an error via ERR_PTR(). |