From: Yipeng Wang Date: Mon, 22 Oct 2018 18:39:48 +0000 (-0700) Subject: hash: use partial-key hashing X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=c7d93df552c2687d5941eab647a5e198b502d28e;p=dpdk.git hash: use partial-key hashing This commit changes the hashing mechanism to "partial-key hashing" to calculate bucket index and signature of key. This is proposed in Bin Fan, et al's paper "MemC3: Compact and Concurrent MemCache with Dumber Caching and Smarter Hashing". Basically the idea is to use "xor" to derive alternative bucket from current bucket index and signature. With "partial-key hashing", it reduces the bucket memory requirement from two cache lines to one cache line, which improves the memory efficiency and thus the lookup speed. Signed-off-by: Yipeng Wang Reviewed-by: Honnappa Nagarahalli Acked-by: Dharmik Thakkar Acked-by: Bruce Richardson --- diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst index f82c3f0d9a..0a901448a3 100644 --- a/doc/guides/rel_notes/release_18_11.rst +++ b/doc/guides/rel_notes/release_18_11.rst @@ -187,7 +187,8 @@ New Features This new “extendable bucket” feature provides 100% insertion guarantee to the capacity specified by the user by extending hash table with extra buckets when needed to accommodate the unlikely event of intensive hash - collisions. + collisions. In addition, the internal hashing algorithm was changed to use + partial-key hashing to improve memory efficiency and lookup performance. * **Added ability to switch queue deferred start flag on testpmd app.** diff --git a/lib/librte_hash/rte_cuckoo_hash.c b/lib/librte_hash/rte_cuckoo_hash.c index b872caa662..9a489349bb 100644 --- a/lib/librte_hash/rte_cuckoo_hash.c +++ b/lib/librte_hash/rte_cuckoo_hash.c @@ -90,6 +90,36 @@ rte_hash_cmp_eq(const void *key1, const void *key2, const struct rte_hash *h) return cmp_jump_table[h->cmp_jump_table_idx](key1, key2, h->key_len); } +/* + * We use higher 16 bits of hash as the signature value stored in table. + * We use the lower bits for the primary bucket + * location. Then we XOR primary bucket location and the signature + * to get the secondary bucket location. This is same as + * proposed in Bin Fan, et al's paper + * "MemC3: Compact and Concurrent MemCache with Dumber Caching and + * Smarter Hashing". The benefit to use + * XOR is that one could derive the alternative bucket location + * by only using the current bucket location and the signature. + */ +static inline uint16_t +get_short_sig(const hash_sig_t hash) +{ + return hash >> 16; +} + +static inline uint32_t +get_prim_bucket_index(const struct rte_hash *h, const hash_sig_t hash) +{ + return hash & h->bucket_bitmask; +} + +static inline uint32_t +get_alt_bucket_index(const struct rte_hash *h, + uint32_t cur_bkt_idx, uint16_t sig) +{ + return (cur_bkt_idx ^ sig) & h->bucket_bitmask; +} + struct rte_hash * rte_hash_create(const struct rte_hash_parameters *params) { @@ -327,9 +357,7 @@ rte_hash_create(const struct rte_hash_parameters *params) h->ext_table_support = ext_table_support; #if defined(RTE_ARCH_X86) - if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX2)) - h->sig_cmp_fn = RTE_HASH_COMPARE_AVX2; - else if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE2)) + if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE2)) h->sig_cmp_fn = RTE_HASH_COMPARE_SSE; else #endif @@ -417,18 +445,6 @@ rte_hash_hash(const struct rte_hash *h, const void *key) return h->hash_func(key, h->key_len, h->hash_func_init_val); } -/* Calc the secondary hash value from the primary hash value of a given key */ -static inline hash_sig_t -rte_hash_secondary_hash(const hash_sig_t primary_hash) -{ - static const unsigned all_bits_shift = 12; - static const unsigned alt_bits_xor = 0x5bd1e995; - - uint32_t tag = primary_hash >> all_bits_shift; - - return primary_hash ^ ((tag + 1) * alt_bits_xor); -} - int32_t rte_hash_count(const struct rte_hash *h) { @@ -560,14 +576,13 @@ enqueue_slot_back(const struct rte_hash *h, /* Search a key from bucket and update its data */ static inline int32_t search_and_update(const struct rte_hash *h, void *data, const void *key, - struct rte_hash_bucket *bkt, hash_sig_t sig, hash_sig_t alt_hash) + struct rte_hash_bucket *bkt, uint16_t sig) { int i; struct rte_hash_key *k, *keys = h->key_store; for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) { - if (bkt->sig_current[i] == sig && - bkt->sig_alt[i] == alt_hash) { + if (bkt->sig_current[i] == sig) { k = (struct rte_hash_key *) ((char *)keys + bkt->key_idx[i] * h->key_entry_size); if (rte_hash_cmp_eq(key, k->key, h) == 0) { @@ -594,7 +609,7 @@ rte_hash_cuckoo_insert_mw(const struct rte_hash *h, struct rte_hash_bucket *prim_bkt, struct rte_hash_bucket *sec_bkt, const struct rte_hash_key *key, void *data, - hash_sig_t sig, hash_sig_t alt_hash, uint32_t new_idx, + uint16_t sig, uint32_t new_idx, int32_t *ret_val) { unsigned int i; @@ -605,7 +620,7 @@ rte_hash_cuckoo_insert_mw(const struct rte_hash *h, /* Check if key was inserted after last check but before this * protected region in case of inserting duplicated keys. */ - ret = search_and_update(h, data, key, prim_bkt, sig, alt_hash); + ret = search_and_update(h, data, key, prim_bkt, sig); if (ret != -1) { __hash_rw_writer_unlock(h); *ret_val = ret; @@ -613,7 +628,7 @@ rte_hash_cuckoo_insert_mw(const struct rte_hash *h, } FOR_EACH_BUCKET(cur_bkt, sec_bkt) { - ret = search_and_update(h, data, key, cur_bkt, alt_hash, sig); + ret = search_and_update(h, data, key, cur_bkt, sig); if (ret != -1) { __hash_rw_writer_unlock(h); *ret_val = ret; @@ -628,7 +643,6 @@ rte_hash_cuckoo_insert_mw(const struct rte_hash *h, /* Check if slot is available */ if (likely(prim_bkt->key_idx[i] == EMPTY_SLOT)) { prim_bkt->sig_current[i] = sig; - prim_bkt->sig_alt[i] = alt_hash; prim_bkt->key_idx[i] = new_idx; break; } @@ -653,7 +667,7 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, struct rte_hash_bucket *alt_bkt, const struct rte_hash_key *key, void *data, struct queue_node *leaf, uint32_t leaf_slot, - hash_sig_t sig, hash_sig_t alt_hash, uint32_t new_idx, + uint16_t sig, uint32_t new_idx, int32_t *ret_val) { uint32_t prev_alt_bkt_idx; @@ -674,7 +688,7 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, /* Check if key was inserted after last check but before this * protected region. */ - ret = search_and_update(h, data, key, bkt, sig, alt_hash); + ret = search_and_update(h, data, key, bkt, sig); if (ret != -1) { __hash_rw_writer_unlock(h); *ret_val = ret; @@ -682,7 +696,7 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, } FOR_EACH_BUCKET(cur_bkt, alt_bkt) { - ret = search_and_update(h, data, key, cur_bkt, alt_hash, sig); + ret = search_and_update(h, data, key, cur_bkt, sig); if (ret != -1) { __hash_rw_writer_unlock(h); *ret_val = ret; @@ -695,8 +709,9 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, prev_bkt = prev_node->bkt; prev_slot = curr_node->prev_slot; - prev_alt_bkt_idx = - prev_bkt->sig_alt[prev_slot] & h->bucket_bitmask; + prev_alt_bkt_idx = get_alt_bucket_index(h, + prev_node->cur_bkt_idx, + prev_bkt->sig_current[prev_slot]); if (unlikely(&h->buckets[prev_alt_bkt_idx] != curr_bkt)) { @@ -710,10 +725,8 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, * Cuckoo insert to move elements back to its * primary bucket if available */ - curr_bkt->sig_alt[curr_slot] = - prev_bkt->sig_current[prev_slot]; curr_bkt->sig_current[curr_slot] = - prev_bkt->sig_alt[prev_slot]; + prev_bkt->sig_current[prev_slot]; curr_bkt->key_idx[curr_slot] = prev_bkt->key_idx[prev_slot]; @@ -723,7 +736,6 @@ rte_hash_cuckoo_move_insert_mw(const struct rte_hash *h, } curr_bkt->sig_current[curr_slot] = sig; - curr_bkt->sig_alt[curr_slot] = alt_hash; curr_bkt->key_idx[curr_slot] = new_idx; __hash_rw_writer_unlock(h); @@ -741,39 +753,44 @@ rte_hash_cuckoo_make_space_mw(const struct rte_hash *h, struct rte_hash_bucket *bkt, struct rte_hash_bucket *sec_bkt, const struct rte_hash_key *key, void *data, - hash_sig_t sig, hash_sig_t alt_hash, + uint16_t sig, uint32_t bucket_idx, uint32_t new_idx, int32_t *ret_val) { unsigned int i; struct queue_node queue[RTE_HASH_BFS_QUEUE_MAX_LEN]; struct queue_node *tail, *head; struct rte_hash_bucket *curr_bkt, *alt_bkt; + uint32_t cur_idx, alt_idx; tail = queue; head = queue + 1; tail->bkt = bkt; tail->prev = NULL; tail->prev_slot = -1; + tail->cur_bkt_idx = bucket_idx; /* Cuckoo bfs Search */ while (likely(tail != head && head < queue + RTE_HASH_BFS_QUEUE_MAX_LEN - RTE_HASH_BUCKET_ENTRIES)) { curr_bkt = tail->bkt; + cur_idx = tail->cur_bkt_idx; for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) { if (curr_bkt->key_idx[i] == EMPTY_SLOT) { int32_t ret = rte_hash_cuckoo_move_insert_mw(h, bkt, sec_bkt, key, data, - tail, i, sig, alt_hash, + tail, i, sig, new_idx, ret_val); if (likely(ret != -1)) return ret; } /* Enqueue new node and keep prev node info */ - alt_bkt = &(h->buckets[curr_bkt->sig_alt[i] - & h->bucket_bitmask]); + alt_idx = get_alt_bucket_index(h, cur_idx, + curr_bkt->sig_current[i]); + alt_bkt = &(h->buckets[alt_idx]); head->bkt = alt_bkt; + head->cur_bkt_idx = alt_idx; head->prev = tail; head->prev_slot = i; head++; @@ -788,7 +805,7 @@ static inline int32_t __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t sig, void *data) { - hash_sig_t alt_hash; + uint16_t short_sig; uint32_t prim_bucket_idx, sec_bucket_idx; struct rte_hash_bucket *prim_bkt, *sec_bkt, *cur_bkt; struct rte_hash_key *new_k, *keys = h->key_store; @@ -803,18 +820,17 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, int32_t ret_val; struct rte_hash_bucket *last; - prim_bucket_idx = sig & h->bucket_bitmask; + short_sig = get_short_sig(sig); + prim_bucket_idx = get_prim_bucket_index(h, sig); + sec_bucket_idx = get_alt_bucket_index(h, prim_bucket_idx, short_sig); prim_bkt = &h->buckets[prim_bucket_idx]; - rte_prefetch0(prim_bkt); - - alt_hash = rte_hash_secondary_hash(sig); - sec_bucket_idx = alt_hash & h->bucket_bitmask; sec_bkt = &h->buckets[sec_bucket_idx]; + rte_prefetch0(prim_bkt); rte_prefetch0(sec_bkt); /* Check if key is already inserted in primary location */ __hash_rw_writer_lock(h); - ret = search_and_update(h, data, key, prim_bkt, sig, alt_hash); + ret = search_and_update(h, data, key, prim_bkt, short_sig); if (ret != -1) { __hash_rw_writer_unlock(h); return ret; @@ -822,12 +838,13 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, /* Check if key is already inserted in secondary location */ FOR_EACH_BUCKET(cur_bkt, sec_bkt) { - ret = search_and_update(h, data, key, cur_bkt, alt_hash, sig); + ret = search_and_update(h, data, key, cur_bkt, short_sig); if (ret != -1) { __hash_rw_writer_unlock(h); return ret; } } + __hash_rw_writer_unlock(h); /* Did not find a match, so get a new slot for storing the new key */ @@ -865,7 +882,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, /* Find an empty slot and insert */ ret = rte_hash_cuckoo_insert_mw(h, prim_bkt, sec_bkt, key, data, - sig, alt_hash, new_idx, &ret_val); + short_sig, new_idx, &ret_val); if (ret == 0) return new_idx - 1; else if (ret == 1) { @@ -875,7 +892,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, /* Primary bucket full, need to make space for new entry */ ret = rte_hash_cuckoo_make_space_mw(h, prim_bkt, sec_bkt, key, data, - sig, alt_hash, new_idx, &ret_val); + short_sig, prim_bucket_idx, new_idx, &ret_val); if (ret == 0) return new_idx - 1; else if (ret == 1) { @@ -885,7 +902,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, /* Also search secondary bucket to get better occupancy */ ret = rte_hash_cuckoo_make_space_mw(h, sec_bkt, prim_bkt, key, data, - alt_hash, sig, new_idx, &ret_val); + short_sig, sec_bucket_idx, new_idx, &ret_val); if (ret == 0) return new_idx - 1; @@ -905,14 +922,14 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, */ __hash_rw_writer_lock(h); /* We check for duplicates again since could be inserted before the lock */ - ret = search_and_update(h, data, key, prim_bkt, sig, alt_hash); + ret = search_and_update(h, data, key, prim_bkt, short_sig); if (ret != -1) { enqueue_slot_back(h, cached_free_slots, slot_id); goto failure; } FOR_EACH_BUCKET(cur_bkt, sec_bkt) { - ret = search_and_update(h, data, key, cur_bkt, alt_hash, sig); + ret = search_and_update(h, data, key, cur_bkt, short_sig); if (ret != -1) { enqueue_slot_back(h, cached_free_slots, slot_id); goto failure; @@ -924,8 +941,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) { /* Check if slot is available */ if (likely(cur_bkt->key_idx[i] == EMPTY_SLOT)) { - cur_bkt->sig_current[i] = alt_hash; - cur_bkt->sig_alt[i] = sig; + cur_bkt->sig_current[i] = short_sig; cur_bkt->key_idx[i] = new_idx; __hash_rw_writer_unlock(h); return new_idx - 1; @@ -943,8 +959,7 @@ __rte_hash_add_key_with_hash(const struct rte_hash *h, const void *key, bkt_id = (uint32_t)((uintptr_t)ext_bkt_id) - 1; /* Use the first location of the new bucket */ - (h->buckets_ext[bkt_id]).sig_current[0] = alt_hash; - (h->buckets_ext[bkt_id]).sig_alt[0] = sig; + (h->buckets_ext[bkt_id]).sig_current[0] = short_sig; (h->buckets_ext[bkt_id]).key_idx[0] = new_idx; /* Link the new bucket to sec bucket linked list */ last = rte_hash_get_last_bkt(sec_bkt); @@ -1003,7 +1018,7 @@ rte_hash_add_key_data(const struct rte_hash *h, const void *key, void *data) /* Search one bucket to find the match key */ static inline int32_t -search_one_bucket(const struct rte_hash *h, const void *key, hash_sig_t sig, +search_one_bucket(const struct rte_hash *h, const void *key, uint16_t sig, void **data, const struct rte_hash_bucket *bkt) { int i; @@ -1032,30 +1047,30 @@ static inline int32_t __rte_hash_lookup_with_hash(const struct rte_hash *h, const void *key, hash_sig_t sig, void **data) { - uint32_t bucket_idx; - hash_sig_t alt_hash; + uint32_t prim_bucket_idx, sec_bucket_idx; struct rte_hash_bucket *bkt, *cur_bkt; int ret; + uint16_t short_sig; - bucket_idx = sig & h->bucket_bitmask; - bkt = &h->buckets[bucket_idx]; + short_sig = get_short_sig(sig); + prim_bucket_idx = get_prim_bucket_index(h, sig); + sec_bucket_idx = get_alt_bucket_index(h, prim_bucket_idx, short_sig); + bkt = &h->buckets[prim_bucket_idx]; __hash_rw_reader_lock(h); /* Check if key is in primary location */ - ret = search_one_bucket(h, key, sig, data, bkt); + ret = search_one_bucket(h, key, short_sig, data, bkt); if (ret != -1) { __hash_rw_reader_unlock(h); return ret; } /* Calculate secondary hash */ - alt_hash = rte_hash_secondary_hash(sig); - bucket_idx = alt_hash & h->bucket_bitmask; - bkt = &h->buckets[bucket_idx]; + bkt = &h->buckets[sec_bucket_idx]; /* Check if key is in secondary location */ FOR_EACH_BUCKET(cur_bkt, bkt) { - ret = search_one_bucket(h, key, alt_hash, data, cur_bkt); + ret = search_one_bucket(h, key, short_sig, data, cur_bkt); if (ret != -1) { __hash_rw_reader_unlock(h); return ret; @@ -1102,7 +1117,6 @@ remove_entry(const struct rte_hash *h, struct rte_hash_bucket *bkt, unsigned i) struct lcore_cache *cached_free_slots; bkt->sig_current[i] = NULL_SIGNATURE; - bkt->sig_alt[i] = NULL_SIGNATURE; if (h->multi_writer_support) { lcore_id = rte_lcore_id(); cached_free_slots = &h->local_free_slots[lcore_id]; @@ -1141,9 +1155,7 @@ __rte_hash_compact_ll(struct rte_hash_bucket *cur_bkt, int pos) { if (last_bkt->key_idx[i] != EMPTY_SLOT) { cur_bkt->key_idx[pos] = last_bkt->key_idx[i]; cur_bkt->sig_current[pos] = last_bkt->sig_current[i]; - cur_bkt->sig_alt[pos] = last_bkt->sig_alt[i]; last_bkt->sig_current[i] = NULL_SIGNATURE; - last_bkt->sig_alt[i] = NULL_SIGNATURE; last_bkt->key_idx[i] = EMPTY_SLOT; return; } @@ -1153,7 +1165,7 @@ __rte_hash_compact_ll(struct rte_hash_bucket *cur_bkt, int pos) { /* Search one bucket and remove the matched key */ static inline int32_t search_and_remove(const struct rte_hash *h, const void *key, - struct rte_hash_bucket *bkt, hash_sig_t sig, int *pos) + struct rte_hash_bucket *bkt, uint16_t sig, int *pos) { struct rte_hash_key *k, *keys = h->key_store; unsigned int i; @@ -1185,19 +1197,21 @@ static inline int32_t __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key, hash_sig_t sig) { - uint32_t bucket_idx; - hash_sig_t alt_hash; + uint32_t prim_bucket_idx, sec_bucket_idx; struct rte_hash_bucket *prim_bkt, *sec_bkt, *prev_bkt, *last_bkt; struct rte_hash_bucket *cur_bkt; int pos; int32_t ret, i; + uint16_t short_sig; - bucket_idx = sig & h->bucket_bitmask; - prim_bkt = &h->buckets[bucket_idx]; + short_sig = get_short_sig(sig); + prim_bucket_idx = get_prim_bucket_index(h, sig); + sec_bucket_idx = get_alt_bucket_index(h, prim_bucket_idx, short_sig); + prim_bkt = &h->buckets[prim_bucket_idx]; __hash_rw_writer_lock(h); /* look for key in primary bucket */ - ret = search_and_remove(h, key, prim_bkt, sig, &pos); + ret = search_and_remove(h, key, prim_bkt, short_sig, &pos); if (ret != -1) { __rte_hash_compact_ll(prim_bkt, pos); last_bkt = prim_bkt->next; @@ -1206,12 +1220,10 @@ __rte_hash_del_key_with_hash(const struct rte_hash *h, const void *key, } /* Calculate secondary hash */ - alt_hash = rte_hash_secondary_hash(sig); - bucket_idx = alt_hash & h->bucket_bitmask; - sec_bkt = &h->buckets[bucket_idx]; + sec_bkt = &h->buckets[sec_bucket_idx]; FOR_EACH_BUCKET(cur_bkt, sec_bkt) { - ret = search_and_remove(h, key, cur_bkt, alt_hash, &pos); + ret = search_and_remove(h, key, cur_bkt, short_sig, &pos); if (ret != -1) { __rte_hash_compact_ll(cur_bkt, pos); last_bkt = sec_bkt->next; @@ -1288,55 +1300,35 @@ static inline void compare_signatures(uint32_t *prim_hash_matches, uint32_t *sec_hash_matches, const struct rte_hash_bucket *prim_bkt, const struct rte_hash_bucket *sec_bkt, - hash_sig_t prim_hash, hash_sig_t sec_hash, + uint16_t sig, enum rte_hash_sig_compare_function sig_cmp_fn) { unsigned int i; + /* For match mask the first bit of every two bits indicates the match */ switch (sig_cmp_fn) { -#ifdef RTE_MACHINE_CPUFLAG_AVX2 - case RTE_HASH_COMPARE_AVX2: - *prim_hash_matches = _mm256_movemask_ps((__m256)_mm256_cmpeq_epi32( - _mm256_load_si256( - (__m256i const *)prim_bkt->sig_current), - _mm256_set1_epi32(prim_hash))); - *sec_hash_matches = _mm256_movemask_ps((__m256)_mm256_cmpeq_epi32( - _mm256_load_si256( - (__m256i const *)sec_bkt->sig_current), - _mm256_set1_epi32(sec_hash))); - break; -#endif #ifdef RTE_MACHINE_CPUFLAG_SSE2 case RTE_HASH_COMPARE_SSE: - /* Compare the first 4 signatures in the bucket */ - *prim_hash_matches = _mm_movemask_ps((__m128)_mm_cmpeq_epi16( + /* Compare all signatures in the bucket */ + *prim_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16( _mm_load_si128( (__m128i const *)prim_bkt->sig_current), - _mm_set1_epi32(prim_hash))); - *prim_hash_matches |= (_mm_movemask_ps((__m128)_mm_cmpeq_epi16( - _mm_load_si128( - (__m128i const *)&prim_bkt->sig_current[4]), - _mm_set1_epi32(prim_hash)))) << 4; - /* Compare the first 4 signatures in the bucket */ - *sec_hash_matches = _mm_movemask_ps((__m128)_mm_cmpeq_epi16( + _mm_set1_epi16(sig))); + /* Compare all signatures in the bucket */ + *sec_hash_matches = _mm_movemask_epi8(_mm_cmpeq_epi16( _mm_load_si128( (__m128i const *)sec_bkt->sig_current), - _mm_set1_epi32(sec_hash))); - *sec_hash_matches |= (_mm_movemask_ps((__m128)_mm_cmpeq_epi16( - _mm_load_si128( - (__m128i const *)&sec_bkt->sig_current[4]), - _mm_set1_epi32(sec_hash)))) << 4; + _mm_set1_epi16(sig))); break; #endif default: for (i = 0; i < RTE_HASH_BUCKET_ENTRIES; i++) { *prim_hash_matches |= - ((prim_hash == prim_bkt->sig_current[i]) << i); + ((sig == prim_bkt->sig_current[i]) << (i << 1)); *sec_hash_matches |= - ((sec_hash == sec_bkt->sig_current[i]) << i); + ((sig == sec_bkt->sig_current[i]) << (i << 1)); } } - } #define PREFETCH_OFFSET 4 @@ -1349,7 +1341,9 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, int32_t i; int32_t ret; uint32_t prim_hash[RTE_HASH_LOOKUP_BULK_MAX]; - uint32_t sec_hash[RTE_HASH_LOOKUP_BULK_MAX]; + uint32_t prim_index[RTE_HASH_LOOKUP_BULK_MAX]; + uint32_t sec_index[RTE_HASH_LOOKUP_BULK_MAX]; + uint16_t sig[RTE_HASH_LOOKUP_BULK_MAX]; const struct rte_hash_bucket *primary_bkt[RTE_HASH_LOOKUP_BULK_MAX]; const struct rte_hash_bucket *secondary_bkt[RTE_HASH_LOOKUP_BULK_MAX]; uint32_t prim_hitmask[RTE_HASH_LOOKUP_BULK_MAX] = {0}; @@ -1368,10 +1362,13 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, rte_prefetch0(keys[i + PREFETCH_OFFSET]); prim_hash[i] = rte_hash_hash(h, keys[i]); - sec_hash[i] = rte_hash_secondary_hash(prim_hash[i]); - primary_bkt[i] = &h->buckets[prim_hash[i] & h->bucket_bitmask]; - secondary_bkt[i] = &h->buckets[sec_hash[i] & h->bucket_bitmask]; + sig[i] = get_short_sig(prim_hash[i]); + prim_index[i] = get_prim_bucket_index(h, prim_hash[i]); + sec_index[i] = get_alt_bucket_index(h, prim_index[i], sig[i]); + + primary_bkt[i] = &h->buckets[prim_index[i]]; + secondary_bkt[i] = &h->buckets[sec_index[i]]; rte_prefetch0(primary_bkt[i]); rte_prefetch0(secondary_bkt[i]); @@ -1380,10 +1377,13 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, /* Calculate and prefetch rest of the buckets */ for (; i < num_keys; i++) { prim_hash[i] = rte_hash_hash(h, keys[i]); - sec_hash[i] = rte_hash_secondary_hash(prim_hash[i]); - primary_bkt[i] = &h->buckets[prim_hash[i] & h->bucket_bitmask]; - secondary_bkt[i] = &h->buckets[sec_hash[i] & h->bucket_bitmask]; + sig[i] = get_short_sig(prim_hash[i]); + prim_index[i] = get_prim_bucket_index(h, prim_hash[i]); + sec_index[i] = get_alt_bucket_index(h, prim_index[i], sig[i]); + + primary_bkt[i] = &h->buckets[prim_index[i]]; + secondary_bkt[i] = &h->buckets[sec_index[i]]; rte_prefetch0(primary_bkt[i]); rte_prefetch0(secondary_bkt[i]); @@ -1394,10 +1394,11 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, for (i = 0; i < num_keys; i++) { compare_signatures(&prim_hitmask[i], &sec_hitmask[i], primary_bkt[i], secondary_bkt[i], - prim_hash[i], sec_hash[i], h->sig_cmp_fn); + sig[i], h->sig_cmp_fn); if (prim_hitmask[i]) { - uint32_t first_hit = __builtin_ctzl(prim_hitmask[i]); + uint32_t first_hit = + __builtin_ctzl(prim_hitmask[i]) >> 1; uint32_t key_idx = primary_bkt[i]->key_idx[first_hit]; const struct rte_hash_key *key_slot = (const struct rte_hash_key *)( @@ -1408,7 +1409,8 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, } if (sec_hitmask[i]) { - uint32_t first_hit = __builtin_ctzl(sec_hitmask[i]); + uint32_t first_hit = + __builtin_ctzl(sec_hitmask[i]) >> 1; uint32_t key_idx = secondary_bkt[i]->key_idx[first_hit]; const struct rte_hash_key *key_slot = (const struct rte_hash_key *)( @@ -1422,7 +1424,8 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, for (i = 0; i < num_keys; i++) { positions[i] = -ENOENT; while (prim_hitmask[i]) { - uint32_t hit_index = __builtin_ctzl(prim_hitmask[i]); + uint32_t hit_index = + __builtin_ctzl(prim_hitmask[i]) >> 1; uint32_t key_idx = primary_bkt[i]->key_idx[hit_index]; const struct rte_hash_key *key_slot = @@ -1441,11 +1444,12 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, positions[i] = key_idx - 1; goto next_key; } - prim_hitmask[i] &= ~(1 << (hit_index)); + prim_hitmask[i] &= ~(3ULL << (hit_index << 1)); } while (sec_hitmask[i]) { - uint32_t hit_index = __builtin_ctzl(sec_hitmask[i]); + uint32_t hit_index = + __builtin_ctzl(sec_hitmask[i]) >> 1; uint32_t key_idx = secondary_bkt[i]->key_idx[hit_index]; const struct rte_hash_key *key_slot = @@ -1465,7 +1469,7 @@ __rte_hash_lookup_bulk(const struct rte_hash *h, const void **keys, positions[i] = key_idx - 1; goto next_key; } - sec_hitmask[i] &= ~(1 << (hit_index)); + sec_hitmask[i] &= ~(3ULL << (hit_index << 1)); } next_key: @@ -1488,10 +1492,10 @@ next_key: FOR_EACH_BUCKET(cur_bkt, next_bkt) { if (data != NULL) ret = search_one_bucket(h, keys[i], - sec_hash[i], &data[i], cur_bkt); + sig[i], &data[i], cur_bkt); else ret = search_one_bucket(h, keys[i], - sec_hash[i], NULL, cur_bkt); + sig[i], NULL, cur_bkt); if (ret != -1) { positions[i] = ret; hits |= 1ULL << i; diff --git a/lib/librte_hash/rte_cuckoo_hash.h b/lib/librte_hash/rte_cuckoo_hash.h index e6015203c5..7753cd819d 100644 --- a/lib/librte_hash/rte_cuckoo_hash.h +++ b/lib/librte_hash/rte_cuckoo_hash.h @@ -129,18 +129,15 @@ struct rte_hash_key { enum rte_hash_sig_compare_function { RTE_HASH_COMPARE_SCALAR = 0, RTE_HASH_COMPARE_SSE, - RTE_HASH_COMPARE_AVX2, RTE_HASH_COMPARE_NUM }; /** Bucket structure */ struct rte_hash_bucket { - hash_sig_t sig_current[RTE_HASH_BUCKET_ENTRIES]; + uint16_t sig_current[RTE_HASH_BUCKET_ENTRIES]; uint32_t key_idx[RTE_HASH_BUCKET_ENTRIES]; - hash_sig_t sig_alt[RTE_HASH_BUCKET_ENTRIES]; - uint8_t flag[RTE_HASH_BUCKET_ENTRIES]; void *next; @@ -193,6 +190,7 @@ struct rte_hash { struct queue_node { struct rte_hash_bucket *bkt; /* Current bucket on the bfs search */ + uint32_t cur_bkt_idx; struct queue_node *prev; /* Parent(bucket) in search path */ int prev_slot; /* Parent(slot) in search path */ diff --git a/lib/librte_hash/rte_hash.h b/lib/librte_hash/rte_hash.h index 11d8e28a7d..6ace64e659 100644 --- a/lib/librte_hash/rte_hash.h +++ b/lib/librte_hash/rte_hash.h @@ -40,7 +40,10 @@ extern "C" { /** Flag to indicate the extendabe bucket table feature should be used */ #define RTE_HASH_EXTRA_FLAGS_EXT_TABLE 0x08 -/** Signature of key that is stored internally. */ +/** + * The type of hash value of a key. + * It should be a value of at least 32bit with fully random pattern. + */ typedef uint32_t hash_sig_t; /** Type of function that can be used for calculating the hash value. */