table: rework variable size key ext hash tables
authorCristian Dumitrescu <cristian.dumitrescu@intel.com>
Wed, 18 Oct 2017 15:03:44 +0000 (16:03 +0100)
committerCristian Dumitrescu <cristian.dumitrescu@intel.com>
Tue, 24 Oct 2017 11:08:08 +0000 (13:08 +0200)
Rework for the variable size key extendible bucket (EXT) hash
table to use the mask-based hash function and the unified
parameter structure.

Signed-off-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>
examples/ip_pipeline/pipeline/pipeline_flow_classification_be.c
lib/librte_table/rte_table_hash.h
lib/librte_table/rte_table_hash_ext.c
test/test-pipeline/pipeline_hash.c

index e131a5b..4a4007c 100644 (file)
@@ -516,16 +516,16 @@ static void *pipeline_fc_init(struct pipeline_params *params,
                        .seed = 0,
                };
 
-               struct rte_table_hash_ext_params
-                       table_hash_params = {
+               struct rte_table_hash_params table_hash_params = {
+                       .name = p->name,
                        .key_size = p_fc->key_size,
+                       .key_offset = p_fc->key_offset,
+                       .key_mask = (p_fc->key_mask_present) ?
+                               p_fc->key_mask : NULL,
                        .n_keys = p_fc->n_flows,
                        .n_buckets = p_fc->n_flows / 4,
-                       .n_buckets_ext = p_fc->n_flows / 4,
-                       .f_hash = hash_func[(p_fc->key_size / 8) - 1],
+                       .f_hash = (rte_table_hash_op_hash)hash_func[(p_fc->key_size / 8) - 1],
                        .seed = 0,
-                       .signature_offset = p_fc->hash_offset,
-                       .key_offset = p_fc->key_offset,
                };
 
                struct rte_pipeline_table_params table_params = {
index bb5b83d..0024b99 100644 (file)
@@ -135,40 +135,6 @@ typedef uint64_t (*rte_table_hash_op_hash_nomask)(
        uint32_t key_size,
        uint64_t seed);
 
-/**
- * Hash tables with configurable key size
- *
- */
-/** Extendible bucket hash table parameters */
-struct rte_table_hash_ext_params {
-       /** Key size (number of bytes) */
-       uint32_t key_size;
-
-       /** Maximum number of keys */
-       uint32_t n_keys;
-
-       /** Number of hash table buckets. Each bucket stores up to 4 keys. */
-       uint32_t n_buckets;
-
-       /** Number of hash table bucket extensions. Each bucket extension has
-       space for 4 keys and each bucket can have 0, 1 or more extensions. */
-       uint32_t n_buckets_ext;
-
-       /** Hash function */
-       rte_table_hash_op_hash_nomask f_hash;
-
-       /** Seed value for the hash function */
-       uint64_t seed;
-
-       /** Byte offset within packet meta-data where the 4-byte key signature
-       is located. Valid for pre-computed key signature tables, ignored for
-       do-sig tables. */
-       uint32_t signature_offset;
-
-       /** Byte offset within packet meta-data where the key is located */
-       uint32_t key_offset;
-};
-
 extern struct rte_table_ops rte_table_hash_ext_ops;
 
 /** LRU hash table parameters */
index 72802b8..0a743ad 100644 (file)
@@ -104,9 +104,8 @@ struct rte_table_hash {
        uint32_t n_keys;
        uint32_t n_buckets;
        uint32_t n_buckets_ext;
-       rte_table_hash_op_hash_nomask f_hash;
+       rte_table_hash_op_hash f_hash;
        uint64_t seed;
-       uint32_t signature_offset;
        uint32_t key_offset;
 
        /* Internal */
@@ -120,6 +119,7 @@ struct rte_table_hash {
        struct grinder grinders[RTE_PORT_IN_BURST_SIZE_MAX];
 
        /* Tables */
+       uint64_t *key_mask;
        struct bucket *buckets;
        struct bucket *buckets_ext;
        uint8_t *key_mem;
@@ -132,29 +132,53 @@ struct rte_table_hash {
 };
 
 static int
-check_params_create(struct rte_table_hash_ext_params *params)
+keycmp(void *a, void *b, void *b_mask, uint32_t n_bytes)
 {
-       uint32_t n_buckets_min;
+       uint64_t *a64 = a, *b64 = b, *b_mask64 = b_mask;
+       uint32_t i;
+
+       for (i = 0; i < n_bytes / sizeof(uint64_t); i++)
+               if (a64[i] != (b64[i] & b_mask64[i]))
+                       return 1;
+
+       return 0;
+}
+
+static void
+keycpy(void *dst, void *src, void *src_mask, uint32_t n_bytes)
+{
+       uint64_t *dst64 = dst, *src64 = src, *src_mask64 = src_mask;
+       uint32_t i;
+
+       for (i = 0; i < n_bytes / sizeof(uint64_t); i++)
+               dst64[i] = src64[i] & src_mask64[i];
+}
+
+static int
+check_params_create(struct rte_table_hash_params *params)
+{
+       /* name */
+       if (params->name == NULL) {
+               RTE_LOG(ERR, TABLE, "%s: name invalid value\n", __func__);
+               return -EINVAL;
+       }
 
        /* key_size */
-       if ((params->key_size == 0) ||
+       if ((params->key_size < sizeof(uint64_t)) ||
                (!rte_is_power_of_2(params->key_size))) {
                RTE_LOG(ERR, TABLE, "%s: key_size invalid value\n", __func__);
                return -EINVAL;
        }
 
        /* n_keys */
-       if ((params->n_keys == 0) ||
-               (!rte_is_power_of_2(params->n_keys))) {
+       if (params->n_keys == 0) {
                RTE_LOG(ERR, TABLE, "%s: n_keys invalid value\n", __func__);
                return -EINVAL;
        }
 
        /* n_buckets */
-       n_buckets_min = (params->n_keys + KEYS_PER_BUCKET - 1) / params->n_keys;
        if ((params->n_buckets == 0) ||
-               (!rte_is_power_of_2(params->n_keys)) ||
-               (params->n_buckets < n_buckets_min)) {
+               (!rte_is_power_of_2(params->n_buckets))) {
                RTE_LOG(ERR, TABLE, "%s: n_buckets invalid value\n", __func__);
                return -EINVAL;
        }
@@ -171,15 +195,13 @@ check_params_create(struct rte_table_hash_ext_params *params)
 static void *
 rte_table_hash_ext_create(void *params, int socket_id, uint32_t entry_size)
 {
-       struct rte_table_hash_ext_params *p =
-               params;
+       struct rte_table_hash_params *p = params;
        struct rte_table_hash *t;
-       uint32_t total_size, table_meta_sz;
-       uint32_t bucket_sz, bucket_ext_sz, key_sz;
-       uint32_t key_stack_sz, bkt_ext_stack_sz, data_sz;
-       uint32_t bucket_offset, bucket_ext_offset, key_offset;
-       uint32_t key_stack_offset, bkt_ext_stack_offset, data_offset;
-       uint32_t i;
+       uint64_t table_meta_sz, key_mask_sz, bucket_sz, bucket_ext_sz, key_sz;
+       uint64_t key_stack_sz, bkt_ext_stack_sz, data_sz, total_size;
+       uint64_t key_mask_offset, bucket_offset, bucket_ext_offset, key_offset;
+       uint64_t key_stack_offset, bkt_ext_stack_offset, data_offset;
+       uint32_t n_buckets_ext, i;
 
        /* Check input parameters */
        if ((check_params_create(p) != 0) ||
@@ -188,38 +210,66 @@ rte_table_hash_ext_create(void *params, int socket_id, uint32_t entry_size)
                (sizeof(struct bucket) != (RTE_CACHE_LINE_SIZE / 2)))
                return NULL;
 
+       /*
+        * Table dimensioning
+        *
+        * Objective: Pick the number of bucket extensions (n_buckets_ext) so that
+        * it is guaranteed that n_keys keys can be stored in the table at any time.
+        *
+        * The worst case scenario takes place when all the n_keys keys fall into
+        * the same bucket. Actually, due to the KEYS_PER_BUCKET scheme, the worst
+        * case takes place when (n_keys - KEYS_PER_BUCKET + 1) keys fall into the
+        * same bucket, while the remaining (KEYS_PER_BUCKET - 1) keys each fall
+        * into a different bucket. This case defeats the purpose of the hash table.
+        * It indicates unsuitable f_hash or n_keys to n_buckets ratio.
+        *
+        * n_buckets_ext = n_keys / KEYS_PER_BUCKET + KEYS_PER_BUCKET - 1
+        */
+       n_buckets_ext = p->n_keys / KEYS_PER_BUCKET + KEYS_PER_BUCKET - 1;
+
        /* Memory allocation */
        table_meta_sz = RTE_CACHE_LINE_ROUNDUP(sizeof(struct rte_table_hash));
+       key_mask_sz = RTE_CACHE_LINE_ROUNDUP(p->key_size);
        bucket_sz = RTE_CACHE_LINE_ROUNDUP(p->n_buckets * sizeof(struct bucket));
        bucket_ext_sz =
-               RTE_CACHE_LINE_ROUNDUP(p->n_buckets_ext * sizeof(struct bucket));
+               RTE_CACHE_LINE_ROUNDUP(n_buckets_ext * sizeof(struct bucket));
        key_sz = RTE_CACHE_LINE_ROUNDUP(p->n_keys * p->key_size);
        key_stack_sz = RTE_CACHE_LINE_ROUNDUP(p->n_keys * sizeof(uint32_t));
        bkt_ext_stack_sz =
-               RTE_CACHE_LINE_ROUNDUP(p->n_buckets_ext * sizeof(uint32_t));
+               RTE_CACHE_LINE_ROUNDUP(n_buckets_ext * sizeof(uint32_t));
        data_sz = RTE_CACHE_LINE_ROUNDUP(p->n_keys * entry_size);
-       total_size = table_meta_sz + bucket_sz + bucket_ext_sz + key_sz +
-               key_stack_sz + bkt_ext_stack_sz + data_sz;
+       total_size = table_meta_sz + key_mask_sz + bucket_sz + bucket_ext_sz +
+               key_sz + key_stack_sz + bkt_ext_stack_sz + data_sz;
 
-       t = rte_zmalloc_socket("TABLE", total_size, RTE_CACHE_LINE_SIZE, socket_id);
+       if (total_size > SIZE_MAX) {
+               RTE_LOG(ERR, TABLE, "%s: Cannot allocate %" PRIu64 " bytes"
+                       " for hash table %s\n",
+                       __func__, total_size, p->name);
+               return NULL;
+       }
+
+       t = rte_zmalloc_socket(p->name,
+               (size_t)total_size,
+               RTE_CACHE_LINE_SIZE,
+               socket_id);
        if (t == NULL) {
-               RTE_LOG(ERR, TABLE,
-                       "%s: Cannot allocate %u bytes for hash table\n",
-                       __func__, total_size);
+               RTE_LOG(ERR, TABLE, "%s: Cannot allocate %" PRIu64 " bytes"
+                       " for hash table %s\n",
+                       __func__, total_size, p->name);
                return NULL;
        }
-       RTE_LOG(INFO, TABLE, "%s (%u-byte key): Hash table memory footprint is "
-               "%u bytes\n", __func__, p->key_size, total_size);
+       RTE_LOG(INFO, TABLE, "%s (%u-byte key): Hash table %s memory "
+               "footprint is %" PRIu64 " bytes\n",
+               __func__, p->key_size, p->name, total_size);
 
        /* Memory initialization */
        t->key_size = p->key_size;
        t->entry_size = entry_size;
        t->n_keys = p->n_keys;
        t->n_buckets = p->n_buckets;
-       t->n_buckets_ext = p->n_buckets_ext;
+       t->n_buckets_ext = n_buckets_ext;
        t->f_hash = p->f_hash;
        t->seed = p->seed;
-       t->signature_offset = p->signature_offset;
        t->key_offset = p->key_offset;
 
        /* Internal */
@@ -228,13 +278,15 @@ rte_table_hash_ext_create(void *params, int socket_id, uint32_t entry_size)
        t->data_size_shl = __builtin_ctzl(entry_size);
 
        /* Tables */
-       bucket_offset = 0;
+       key_mask_offset = 0;
+       bucket_offset = key_mask_offset + key_mask_sz;
        bucket_ext_offset = bucket_offset + bucket_sz;
        key_offset = bucket_ext_offset + bucket_ext_sz;
        key_stack_offset = key_offset + key_sz;
        bkt_ext_stack_offset = key_stack_offset + key_stack_sz;
        data_offset = bkt_ext_stack_offset + bkt_ext_stack_sz;
 
+       t->key_mask = (uint64_t *) &t->memory[key_mask_offset];
        t->buckets = (struct bucket *) &t->memory[bucket_offset];
        t->buckets_ext = (struct bucket *) &t->memory[bucket_ext_offset];
        t->key_mem = &t->memory[key_offset];
@@ -242,6 +294,12 @@ rte_table_hash_ext_create(void *params, int socket_id, uint32_t entry_size)
        t->bkt_ext_stack = (uint32_t *) &t->memory[bkt_ext_stack_offset];
        t->data_mem = &t->memory[data_offset];
 
+       /* Key mask */
+       if (p->key_mask == NULL)
+               memset(t->key_mask, 0xFF, p->key_size);
+       else
+               memcpy(t->key_mask, p->key_mask, p->key_size);
+
        /* Key stack */
        for (i = 0; i < t->n_keys; i++)
                t->key_stack[i] = t->n_keys - 1 - i;
@@ -277,7 +335,7 @@ rte_table_hash_ext_entry_add(void *table, void *key, void *entry,
        uint64_t sig;
        uint32_t bkt_index, i;
 
-       sig = t->f_hash(key, t->key_size, t->seed);
+       sig = t->f_hash(key, t->key_mask, t->key_size, t->seed);
        bkt_index = sig & t->bucket_mask;
        bkt0 = &t->buckets[bkt_index];
        sig = (sig >> 16) | 1LLU;
@@ -290,7 +348,7 @@ rte_table_hash_ext_entry_add(void *table, void *key, void *entry,
                        uint8_t *bkt_key =
                                &t->key_mem[bkt_key_index << t->key_size_shl];
 
-                       if ((sig == bkt_sig) && (memcmp(key, bkt_key,
+                       if ((sig == bkt_sig) && (keycmp(bkt_key, key, t->key_mask,
                                t->key_size) == 0)) {
                                uint8_t *data = &t->data_mem[bkt_key_index <<
                                        t->data_size_shl];
@@ -327,7 +385,7 @@ rte_table_hash_ext_entry_add(void *table, void *key, void *entry,
 
                                bkt->sig[i] = (uint16_t) sig;
                                bkt->key_pos[i] = bkt_key_index;
-                               memcpy(bkt_key, key, t->key_size);
+                               keycpy(bkt_key, key, t->key_mask, t->key_size);
                                memcpy(data, entry, t->entry_size);
 
                                *key_found = 0;
@@ -358,7 +416,7 @@ rte_table_hash_ext_entry_add(void *table, void *key, void *entry,
                /* Install new key into bucket */
                bkt->sig[0] = (uint16_t) sig;
                bkt->key_pos[0] = bkt_key_index;
-               memcpy(bkt_key, key, t->key_size);
+               keycpy(bkt_key, key, t->key_mask, t->key_size);
                memcpy(data, entry, t->entry_size);
 
                *key_found = 0;
@@ -378,7 +436,7 @@ void *entry)
        uint64_t sig;
        uint32_t bkt_index, i;
 
-       sig = t->f_hash(key, t->key_size, t->seed);
+       sig = t->f_hash(key, t->key_mask, t->key_size, t->seed);
        bkt_index = sig & t->bucket_mask;
        bkt0 = &t->buckets[bkt_index];
        sig = (sig >> 16) | 1LLU;
@@ -392,7 +450,7 @@ void *entry)
                        uint8_t *bkt_key = &t->key_mem[bkt_key_index <<
                                t->key_size_shl];
 
-                       if ((sig == bkt_sig) && (memcmp(key, bkt_key,
+                       if ((sig == bkt_sig) && (keycmp(bkt_key, key, t->key_mask,
                                t->key_size) == 0)) {
                                uint8_t *data = &t->data_mem[bkt_key_index <<
                                        t->data_size_shl];
@@ -457,7 +515,7 @@ static int rte_table_hash_ext_lookup_unoptimized(
 
                pkt = pkts[pkt_index];
                key = RTE_MBUF_METADATA_UINT8_PTR(pkt, t->key_offset);
-               sig = (uint64_t) t->f_hash(key, t->key_size, t->seed);
+               sig = (uint64_t) t->f_hash(key, t->key_mask, t->key_size, t->seed);
 
                bkt_index = sig & t->bucket_mask;
                bkt0 = &t->buckets[bkt_index];
@@ -471,8 +529,8 @@ static int rte_table_hash_ext_lookup_unoptimized(
                                uint8_t *bkt_key = &t->key_mem[bkt_key_index <<
                                        t->key_size_shl];
 
-                               if ((sig == bkt_sig) && (memcmp(key, bkt_key,
-                                       t->key_size) == 0)) {
+                               if ((sig == bkt_sig) && (keycmp(bkt_key, key,
+                                       t->key_mask, t->key_size) == 0)) {
                                        uint8_t *data = &t->data_mem[
                                        bkt_key_index << t->data_size_shl];
 
@@ -571,11 +629,12 @@ static int rte_table_hash_ext_lookup_unoptimized(
 {                                                                      \
        uint64_t *pkt_key = RTE_MBUF_METADATA_UINT64_PTR(mbuf, f->key_offset);\
        uint64_t *bkt_key = (uint64_t *) key;                           \
+       uint64_t *key_mask = f->key_mask;                                       \
                                                                        \
        switch (f->key_size) {                                          \
        case 8:                                                         \
        {                                                               \
-               uint64_t xor = pkt_key[0] ^ bkt_key[0];                 \
+               uint64_t xor = (pkt_key[0] & key_mask[0]) ^ bkt_key[0]; \
                match_key = 0;                                          \
                if (xor == 0)                                           \
                        match_key = 1;                                  \
@@ -586,8 +645,8 @@ static int rte_table_hash_ext_lookup_unoptimized(
        {                                                               \
                uint64_t xor[2], or;                                    \
                                                                        \
-               xor[0] = pkt_key[0] ^ bkt_key[0];                       \
-               xor[1] = pkt_key[1] ^ bkt_key[1];                       \
+               xor[0] = (pkt_key[0] & key_mask[0]) ^ bkt_key[0];               \
+               xor[1] = (pkt_key[1] & key_mask[1]) ^ bkt_key[1];               \
                or = xor[0] | xor[1];                                   \
                match_key = 0;                                          \
                if (or == 0)                                            \
@@ -599,10 +658,10 @@ static int rte_table_hash_ext_lookup_unoptimized(
        {                                                               \
                uint64_t xor[4], or;                                    \
                                                                        \
-               xor[0] = pkt_key[0] ^ bkt_key[0];                       \
-               xor[1] = pkt_key[1] ^ bkt_key[1];                       \
-               xor[2] = pkt_key[2] ^ bkt_key[2];                       \
-               xor[3] = pkt_key[3] ^ bkt_key[3];                       \
+               xor[0] = (pkt_key[0] & key_mask[0]) ^ bkt_key[0];               \
+               xor[1] = (pkt_key[1] & key_mask[1]) ^ bkt_key[1];               \
+               xor[2] = (pkt_key[2] & key_mask[2]) ^ bkt_key[2];               \
+               xor[3] = (pkt_key[3] & key_mask[3]) ^ bkt_key[3];               \
                or = xor[0] | xor[1] | xor[2] | xor[3];                 \
                match_key = 0;                                          \
                if (or == 0)                                            \
@@ -614,14 +673,14 @@ static int rte_table_hash_ext_lookup_unoptimized(
        {                                                               \
                uint64_t xor[8], or;                                    \
                                                                        \
-               xor[0] = pkt_key[0] ^ bkt_key[0];                       \
-               xor[1] = pkt_key[1] ^ bkt_key[1];                       \
-               xor[2] = pkt_key[2] ^ bkt_key[2];                       \
-               xor[3] = pkt_key[3] ^ bkt_key[3];                       \
-               xor[4] = pkt_key[4] ^ bkt_key[4];                       \
-               xor[5] = pkt_key[5] ^ bkt_key[5];                       \
-               xor[6] = pkt_key[6] ^ bkt_key[6];                       \
-               xor[7] = pkt_key[7] ^ bkt_key[7];                       \
+               xor[0] = (pkt_key[0] & key_mask[0]) ^ bkt_key[0];               \
+               xor[1] = (pkt_key[1] & key_mask[1]) ^ bkt_key[1];               \
+               xor[2] = (pkt_key[2] & key_mask[2]) ^ bkt_key[2];               \
+               xor[3] = (pkt_key[3] & key_mask[3]) ^ bkt_key[3];               \
+               xor[4] = (pkt_key[4] & key_mask[4]) ^ bkt_key[4];               \
+               xor[5] = (pkt_key[5] & key_mask[5]) ^ bkt_key[5];               \
+               xor[6] = (pkt_key[6] & key_mask[6]) ^ bkt_key[6];               \
+               xor[7] = (pkt_key[7] & key_mask[7]) ^ bkt_key[7];               \
                or = xor[0] | xor[1] | xor[2] | xor[3] |                \
                        xor[4] | xor[5] | xor[6] | xor[7];              \
                match_key = 0;                                          \
@@ -632,7 +691,7 @@ static int rte_table_hash_ext_lookup_unoptimized(
                                                                        \
        default:                                                        \
                match_key = 0;                                          \
-               if (memcmp(pkt_key, bkt_key, f->key_size) == 0)         \
+               if (keycmp(bkt_key, pkt_key, key_mask, f->key_size) == 0)       \
                        match_key = 1;                                  \
        }                                                               \
 }
@@ -688,20 +747,20 @@ static int rte_table_hash_ext_lookup_unoptimized(
        struct bucket *bkt10, *bkt11, *buckets = t->buckets;            \
        uint8_t *key10, *key11;                                         \
        uint64_t bucket_mask = t->bucket_mask;                          \
-       rte_table_hash_op_hash_nomask f_hash = t->f_hash;                       \
+       rte_table_hash_op_hash f_hash = t->f_hash;                      \
        uint64_t seed = t->seed;                                        \
        uint32_t key_size = t->key_size;                                \
        uint32_t key_offset = t->key_offset;                            \
                                                                        \
        mbuf10 = pkts[pkt10_index];                                     \
        key10 = RTE_MBUF_METADATA_UINT8_PTR(mbuf10, key_offset);        \
-       sig10 = (uint64_t) f_hash(key10, key_size, seed);               \
+       sig10 = (uint64_t) f_hash(key10, t->key_mask, key_size, seed);  \
        bkt10_index = sig10 & bucket_mask;                              \
        bkt10 = &buckets[bkt10_index];                                  \
                                                                        \
        mbuf11 = pkts[pkt11_index];                                     \
        key11 = RTE_MBUF_METADATA_UINT8_PTR(mbuf11, key_offset);        \
-       sig11 = (uint64_t) f_hash(key11, key_size, seed);               \
+       sig11 = (uint64_t) f_hash(key11, t->key_mask, key_size, seed);  \
        bkt11_index = sig11 & bucket_mask;                              \
        bkt11 = &buckets[bkt11_index];                                  \
                                                                        \
@@ -969,7 +1028,7 @@ rte_table_hash_ext_stats_read(void *table, struct rte_table_stats *stats, int cl
        return 0;
 }
 
-struct rte_table_ops rte_table_hash_ext_ops  = {
+struct rte_table_ops rte_table_hash_ext_ops     = {
        .f_create = rte_table_hash_ext_create,
        .f_free = rte_table_hash_ext_free,
        .f_add = rte_table_hash_ext_entry_add,
index 2f8c625..13d309d 100644 (file)
@@ -175,15 +175,15 @@ app_main_loop_worker_pipeline_hash(void) {
        case e_APP_PIPELINE_HASH_KEY16_EXT:
        case e_APP_PIPELINE_HASH_KEY32_EXT:
        {
-               struct rte_table_hash_ext_params table_hash_params = {
+               struct rte_table_hash_params table_hash_params = {
+                       .name = "TABLE",
                        .key_size = key_size,
+                       .key_offset = APP_METADATA_OFFSET(32),
+                       .key_mask = NULL,
                        .n_keys = 1 << 24,
                        .n_buckets = 1 << 22,
-                       .n_buckets_ext = 1 << 21,
-                       .f_hash = test_hash,
+                       .f_hash = (rte_table_hash_op_hash)test_hash,
                        .seed = 0,
-                       .signature_offset = APP_METADATA_OFFSET(0),
-                       .key_offset = APP_METADATA_OFFSET(32),
                };
 
                struct rte_pipeline_table_params table_params = {