diff options
Diffstat (limited to 'include/linux/rhashtable.h')
| -rw-r--r-- | include/linux/rhashtable.h | 78 |
1 files changed, 56 insertions, 22 deletions
diff --git a/include/linux/rhashtable.h b/include/linux/rhashtable.h index 5c132d3188be..f2e12a845910 100644 --- a/include/linux/rhashtable.h +++ b/include/linux/rhashtable.h @@ -61,6 +61,7 @@ struct rhlist_head { /** * struct bucket_table - Table of hash buckets * @size: Number of hash buckets + * @nest: Number of bits of first-level nested table. * @rehash: Current bucket being rehashed * @hash_rnd: Random seed to fold into hash * @locks_mask: Mask to apply before accessing locks[] @@ -68,10 +69,12 @@ struct rhlist_head { * @walkers: List of active walkers * @rcu: RCU structure for freeing the table * @future_tbl: Table under construction during rehashing + * @ntbl: Nested table used when out of memory. * @buckets: size * hash buckets */ struct bucket_table { unsigned int size; + unsigned int nest; unsigned int rehash; u32 hash_rnd; unsigned int locks_mask; @@ -81,7 +84,7 @@ struct bucket_table { struct bucket_table __rcu *future_tbl; - struct rhash_head __rcu *buckets[] ____cacheline_aligned_in_smp; + struct rhash_head __rcu *buckets[] ____cacheline_aligned_in_smp; }; /** @@ -374,6 +377,12 @@ void rhashtable_free_and_destroy(struct rhashtable *ht, void *arg); void rhashtable_destroy(struct rhashtable *ht); +struct rhash_head __rcu **rht_bucket_nested(const struct bucket_table *tbl, + unsigned int hash); +struct rhash_head __rcu **rht_bucket_nested_insert(struct rhashtable *ht, + struct bucket_table *tbl, + unsigned int hash); + #define rht_dereference(p, ht) \ rcu_dereference_protected(p, lockdep_rht_mutex_is_held(ht)) @@ -389,6 +398,27 @@ void rhashtable_destroy(struct rhashtable *ht); #define rht_entry(tpos, pos, member) \ ({ tpos = container_of(pos, typeof(*tpos), member); 1; }) +static inline struct rhash_head __rcu *const *rht_bucket( + const struct bucket_table *tbl, unsigned int hash) +{ + return unlikely(tbl->nest) ? rht_bucket_nested(tbl, hash) : + &tbl->buckets[hash]; +} + +static inline struct rhash_head __rcu **rht_bucket_var( + struct bucket_table *tbl, unsigned int hash) +{ + return unlikely(tbl->nest) ? rht_bucket_nested(tbl, hash) : + &tbl->buckets[hash]; +} + +static inline struct rhash_head __rcu **rht_bucket_insert( + struct rhashtable *ht, struct bucket_table *tbl, unsigned int hash) +{ + return unlikely(tbl->nest) ? rht_bucket_nested_insert(ht, tbl, hash) : + &tbl->buckets[hash]; +} + /** * rht_for_each_continue - continue iterating over hash chain * @pos: the &struct rhash_head to use as a loop cursor. @@ -408,7 +438,7 @@ void rhashtable_destroy(struct rhashtable *ht); * @hash: the hash value / bucket index */ #define rht_for_each(pos, tbl, hash) \ - rht_for_each_continue(pos, (tbl)->buckets[hash], tbl, hash) + rht_for_each_continue(pos, *rht_bucket(tbl, hash), tbl, hash) /** * rht_for_each_entry_continue - continue iterating over hash chain @@ -433,7 +463,7 @@ void rhashtable_destroy(struct rhashtable *ht); * @member: name of the &struct rhash_head within the hashable struct. */ #define rht_for_each_entry(tpos, pos, tbl, hash, member) \ - rht_for_each_entry_continue(tpos, pos, (tbl)->buckets[hash], \ + rht_for_each_entry_continue(tpos, pos, *rht_bucket(tbl, hash), \ tbl, hash, member) /** @@ -448,13 +478,13 @@ void rhashtable_destroy(struct rhashtable *ht); * This hash chain list-traversal primitive allows for the looped code to * remove the loop cursor from the list. */ -#define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \ - for (pos = rht_dereference_bucket((tbl)->buckets[hash], tbl, hash), \ - next = !rht_is_a_nulls(pos) ? \ - rht_dereference_bucket(pos->next, tbl, hash) : NULL; \ - (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \ - pos = next, \ - next = !rht_is_a_nulls(pos) ? \ +#define rht_for_each_entry_safe(tpos, pos, next, tbl, hash, member) \ + for (pos = rht_dereference_bucket(*rht_bucket(tbl, hash), tbl, hash), \ + next = !rht_is_a_nulls(pos) ? \ + rht_dereference_bucket(pos->next, tbl, hash) : NULL; \ + (!rht_is_a_nulls(pos)) && rht_entry(tpos, pos, member); \ + pos = next, \ + next = !rht_is_a_nulls(pos) ? \ rht_dereference_bucket(pos->next, tbl, hash) : NULL) /** @@ -485,7 +515,7 @@ void rhashtable_destroy(struct rhashtable *ht); * traversal is guarded by rcu_read_lock(). */ #define rht_for_each_rcu(pos, tbl, hash) \ - rht_for_each_rcu_continue(pos, (tbl)->buckets[hash], tbl, hash) + rht_for_each_rcu_continue(pos, *rht_bucket(tbl, hash), tbl, hash) /** * rht_for_each_entry_rcu_continue - continue iterating over rcu hash chain @@ -518,8 +548,8 @@ void rhashtable_destroy(struct rhashtable *ht); * the _rcu mutation primitives such as rhashtable_insert() as long as the * traversal is guarded by rcu_read_lock(). */ -#define rht_for_each_entry_rcu(tpos, pos, tbl, hash, member) \ - rht_for_each_entry_rcu_continue(tpos, pos, (tbl)->buckets[hash],\ +#define rht_for_each_entry_rcu(tpos, pos, tbl, hash, member) \ + rht_for_each_entry_rcu_continue(tpos, pos, *rht_bucket(tbl, hash), \ tbl, hash, member) /** @@ -565,7 +595,7 @@ static inline struct rhash_head *__rhashtable_lookup( .ht = ht, .key = key, }; - const struct bucket_table *tbl; + struct bucket_table *tbl; struct rhash_head *he; unsigned int hash; @@ -697,8 +727,12 @@ slow_path: } elasticity = ht->elasticity; - pprev = &tbl->buckets[hash]; - rht_for_each(head, tbl, hash) { + pprev = rht_bucket_insert(ht, tbl, hash); + data = ERR_PTR(-ENOMEM); + if (!pprev) + goto out; + + rht_for_each_continue(head, *pprev, tbl, hash) { struct rhlist_head *plist; struct rhlist_head *list; @@ -736,7 +770,7 @@ slow_path: if (unlikely(rht_grow_above_100(ht, tbl))) goto slow_path; - head = rht_dereference_bucket(tbl->buckets[hash], tbl, hash); + head = rht_dereference_bucket(*pprev, tbl, hash); RCU_INIT_POINTER(obj->next, head); if (rhlist) { @@ -746,7 +780,7 @@ slow_path: RCU_INIT_POINTER(list->next, NULL); } - rcu_assign_pointer(tbl->buckets[hash], obj); + rcu_assign_pointer(*pprev, obj); atomic_inc(&ht->nelems); if (rht_grow_above_75(ht, tbl)) @@ -955,8 +989,8 @@ static inline int __rhashtable_remove_fast_one( spin_lock_bh(lock); - pprev = &tbl->buckets[hash]; - rht_for_each(he, tbl, hash) { + pprev = rht_bucket_var(tbl, hash); + rht_for_each_continue(he, *pprev, tbl, hash) { struct rhlist_head *list; list = container_of(he, struct rhlist_head, rhead); @@ -1107,8 +1141,8 @@ static inline int __rhashtable_replace_fast( spin_lock_bh(lock); - pprev = &tbl->buckets[hash]; - rht_for_each(he, tbl, hash) { + pprev = rht_bucket_var(tbl, hash); + rht_for_each_continue(he, *pprev, tbl, hash) { if (he != obj_old) { pprev = &he->next; continue; |