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authorYipeng Wang <yipeng1.wang@intel.com>2018-10-22 11:39:48 -0700
committerThomas Monjalon <thomas@monjalon.net>2018-10-26 01:04:33 +0200
commitc7d93df552c2687d5941eab647a5e198b502d28e (patch)
tree3cd91901a1add219ef0c8ae71e8a78d4f98833ce
parent6f4d0c79072a98282f566ff550f2639479dbc484 (diff)
downloaddpdk-c7d93df552c2687d5941eab647a5e198b502d28e.zip
dpdk-c7d93df552c2687d5941eab647a5e198b502d28e.tar.gz
dpdk-c7d93df552c2687d5941eab647a5e198b502d28e.tar.xz
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 <yipeng1.wang@intel.com> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com> Acked-by: Dharmik Thakkar <dharmik.thakkar@arm.com> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
-rw-r--r--doc/guides/rel_notes/release_18_11.rst3
-rw-r--r--lib/librte_hash/rte_cuckoo_hash.c246
-rw-r--r--lib/librte_hash/rte_cuckoo_hash.h6
-rw-r--r--lib/librte_hash/rte_hash.h5
4 files changed, 133 insertions, 127 deletions
diff --git a/doc/guides/rel_notes/release_18_11.rst b/doc/guides/rel_notes/release_18_11.rst
index f82c3f0..0a90144 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 b872caa..9a48934 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 e601520..7753cd8 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 11d8e28..6ace64e 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. */