table: rework variable size key lru hash table
authorCristian Dumitrescu <cristian.dumitrescu@intel.com>
Wed, 18 Oct 2017 15:03:45 +0000 (16:03 +0100)
committerCristian Dumitrescu <cristian.dumitrescu@intel.com>
Tue, 24 Oct 2017 11:08:25 +0000 (13:08 +0200)
Rework for the variable size key LRU hash table to use the
mask-based hash function and the unified parameter structure.

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

index 0024b99..fb5f4d7 100644 (file)
@@ -137,32 +137,6 @@ typedef uint64_t (*rte_table_hash_op_hash_nomask)(
 
 extern struct rte_table_ops rte_table_hash_ext_ops;
 
-/** LRU hash table parameters */
-struct rte_table_hash_lru_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;
-
-       /** 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_lru_ops;
 
 /**
index 61050f3..eebc1cd 100644 (file)
@@ -84,9 +84,8 @@ struct rte_table_hash {
        uint32_t entry_size;
        uint32_t n_keys;
        uint32_t n_buckets;
-       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 */
@@ -99,6 +98,7 @@ struct rte_table_hash {
        struct grinder grinders[RTE_PORT_IN_BURST_SIZE_MAX];
 
        /* Tables */
+       uint64_t *key_mask;
        struct bucket *buckets;
        uint8_t *key_mem;
        uint8_t *data_mem;
@@ -109,12 +109,39 @@ struct rte_table_hash {
 };
 
 static int
-check_params_create(struct rte_table_hash_lru_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;
@@ -128,10 +155,8 @@ check_params_create(struct rte_table_hash_lru_params *params)
        }
 
        /* 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_keys))) {
                RTE_LOG(ERR, TABLE, "%s: n_buckets invalid value\n", __func__);
                return -EINVAL;
        }
@@ -148,13 +173,13 @@ check_params_create(struct rte_table_hash_lru_params *params)
 static void *
 rte_table_hash_lru_create(void *params, int socket_id, uint32_t entry_size)
 {
-       struct rte_table_hash_lru_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, key_sz, key_stack_sz, data_sz;
-       uint32_t bucket_offset, key_offset, key_stack_offset, data_offset;
-       uint32_t i;
+       uint64_t table_meta_sz, key_mask_sz, bucket_sz, key_sz, key_stack_sz;
+       uint64_t data_sz, total_size;
+       uint64_t key_mask_offset, bucket_offset, key_offset, key_stack_offset;
+       uint64_t data_offset;
+       uint32_t n_buckets, i;
 
        /* Check input parameters */
        if ((check_params_create(p) != 0) ||
@@ -164,33 +189,65 @@ rte_table_hash_lru_create(void *params, int socket_id, uint32_t entry_size)
                return NULL;
        }
 
+       /*
+        * Table dimensioning
+        *
+        * Objective: Pick the number of buckets (n_buckets) so that there a chance
+        * to store n_keys keys in the table.
+        *
+        * Note: Since the buckets do not get extended, it is not possible to
+        * guarantee that n_keys keys can be stored in the table at any time. In the
+        * worst case scenario when all the n_keys fall into the same bucket, only
+        * a maximum of KEYS_PER_BUCKET keys will be stored in the table. This case
+        * defeats the purpose of the hash table. It indicates unsuitable f_hash or
+        * n_keys to n_buckets ratio.
+        *
+        * MIN(n_buckets) = (n_keys + KEYS_PER_BUCKET - 1) / KEYS_PER_BUCKET
+        */
+       n_buckets = rte_align32pow2(
+               (p->n_keys + KEYS_PER_BUCKET - 1) / KEYS_PER_BUCKET);
+       n_buckets = RTE_MAX(n_buckets, p->n_buckets);
+
        /* Memory allocation */
        table_meta_sz = RTE_CACHE_LINE_ROUNDUP(sizeof(struct rte_table_hash));
-       bucket_sz = RTE_CACHE_LINE_ROUNDUP(p->n_buckets * sizeof(struct bucket));
+       key_mask_sz = RTE_CACHE_LINE_ROUNDUP(p->key_size);
+       bucket_sz = RTE_CACHE_LINE_ROUNDUP(n_buckets * 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));
        data_sz = RTE_CACHE_LINE_ROUNDUP(p->n_keys * entry_size);
-       total_size = table_meta_sz + bucket_sz + key_sz + key_stack_sz +
-               data_sz;
+       total_size = table_meta_sz + key_mask_sz + bucket_sz + key_sz +
+               key_stack_sz + data_sz;
+
+       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("TABLE", total_size, RTE_CACHE_LINE_SIZE, socket_id);
+       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);
+                       "%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 = n_buckets;
        t->f_hash = p->f_hash;
        t->seed = p->seed;
-       t->signature_offset = p->signature_offset;
        t->key_offset = p->key_offset;
 
        /* Internal */
@@ -199,16 +256,24 @@ rte_table_hash_lru_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;
        key_offset = bucket_offset + bucket_sz;
        key_stack_offset = key_offset + key_sz;
        data_offset = key_stack_offset + key_stack_sz;
 
+       t->key_mask = (uint64_t *) &t->memory[key_mask_offset];
        t->buckets = (struct bucket *) &t->memory[bucket_offset];
        t->key_mem = &t->memory[key_offset];
        t->key_stack = (uint32_t *) &t->memory[key_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;
@@ -246,7 +311,7 @@ rte_table_hash_lru_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;
        bkt = &t->buckets[bkt_index];
        sig = (sig >> 16) | 1LLU;
@@ -258,8 +323,8 @@ rte_table_hash_lru_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, 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];
 
@@ -292,7 +357,7 @@ rte_table_hash_lru_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);
                        lru_update(bkt, i);
 
@@ -311,7 +376,7 @@ rte_table_hash_lru_entry_add(void *table, void *key, void *entry,
                uint8_t *data = &t->data_mem[bkt_key_index << t->data_size_shl];
 
                bkt->sig[pos] = (uint16_t) sig;
-               memcpy(bkt_key, key, t->key_size);
+               keycpy(bkt_key, key, t->key_mask, t->key_size);
                memcpy(data, entry, t->entry_size);
                lru_update(bkt, pos);
 
@@ -330,7 +395,7 @@ rte_table_hash_lru_entry_delete(void *table, void *key, int *key_found,
        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;
        bkt = &t->buckets[bkt_index];
        sig = (sig >> 16) | 1LLU;
@@ -343,14 +408,15 @@ rte_table_hash_lru_entry_delete(void *table, void *key, int *key_found,
                        t->key_size_shl];
 
                if ((sig == bkt_sig) &&
-                       (memcmp(key, bkt_key, t->key_size) == 0)) {
+                       (keycmp(bkt_key, key, t->key_mask, t->key_size) == 0)) {
                        uint8_t *data = &t->data_mem[bkt_key_index <<
                                t->data_size_shl];
 
                        bkt->sig[i] = 0;
                        t->key_stack[t->key_stack_tos++] = bkt_key_index;
                        *key_found = 1;
-                       memcpy(entry, data, t->entry_size);
+                       if (entry)
+                               memcpy(entry, data, t->entry_size);
                        return 0;
                }
        }
@@ -386,7 +452,7 @@ static int rte_table_hash_lru_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;
                bkt = &t->buckets[bkt_index];
@@ -399,7 +465,7 @@ static int rte_table_hash_lru_lookup_unoptimized(
                        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];
@@ -497,74 +563,75 @@ static int rte_table_hash_lru_lookup_unoptimized(
        match_pos = (LUT_MATCH_POS >> (mask_all << 1)) & 3;     \
 }
 
-#define lookup_cmp_key(mbuf, key, match_key, f)                        \
-{                                                              \
+#define lookup_cmp_key(mbuf, key, match_key, f)                                \
+{                                                                      \
        uint64_t *pkt_key = RTE_MBUF_METADATA_UINT64_PTR(mbuf, f->key_offset);\
-       uint64_t *bkt_key = (uint64_t *) key;                   \
-                                                               \
-       switch (f->key_size) {                                  \
-       case 8:                                                 \
-       {                                                       \
-               uint64_t xor = pkt_key[0] ^ bkt_key[0];         \
-               match_key = 0;                                  \
-               if (xor == 0)                                   \
-                       match_key = 1;                          \
-       }                                                       \
-       break;                                                  \
-                                                               \
-       case 16:                                                \
-       {                                                       \
-               uint64_t xor[2], or;                            \
-                                                               \
-               xor[0] = pkt_key[0] ^ bkt_key[0];               \
-               xor[1] = pkt_key[1] ^ bkt_key[1];               \
-               or = xor[0] | xor[1];                           \
-               match_key = 0;                                  \
-               if (or == 0)                                    \
-                       match_key = 1;                          \
-       }                                                       \
-       break;                                                  \
-                                                               \
-       case 32:                                                \
-       {                                                       \
-               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];               \
-               or = xor[0] | xor[1] | xor[2] | xor[3];         \
-               match_key = 0;                                  \
-               if (or == 0)                                    \
-                       match_key = 1;                          \
-       }                                                       \
-       break;                                                  \
-                                                               \
-       case 64:                                                \
-       {                                                       \
-               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];               \
-               or = xor[0] | xor[1] | xor[2] | xor[3] |        \
-                       xor[4] | xor[5] | xor[6] | xor[7];      \
-               match_key = 0;                                  \
-               if (or == 0)                                    \
-                       match_key = 1;                          \
-       }                                                       \
-       break;                                                  \
-                                                               \
-       default:                                                \
-               match_key = 0;                                  \
-               if (memcmp(pkt_key, bkt_key, f->key_size) == 0) \
-                       match_key = 1;                          \
-       }                                                       \
+       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] & key_mask[0]) ^ bkt_key[0]; \
+               match_key = 0;                                          \
+               if (xor == 0)                                           \
+                       match_key = 1;                                  \
+       }                                                               \
+       break;                                                          \
+                                                                       \
+       case 16:                                                        \
+       {                                                               \
+               uint64_t xor[2], or;                                    \
+                                                                       \
+               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)                                            \
+                       match_key = 1;                                  \
+       }                                                               \
+       break;                                                          \
+                                                                       \
+       case 32:                                                        \
+       {                                                               \
+               uint64_t xor[4], or;                                    \
+                                                                       \
+               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)                                            \
+                       match_key = 1;                                  \
+       }                                                               \
+       break;                                                          \
+                                                                       \
+       case 64:                                                        \
+       {                                                               \
+               uint64_t xor[8], or;                                    \
+                                                                       \
+               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;                                          \
+               if (or == 0)                                            \
+                       match_key = 1;                                  \
+       }                                                               \
+       break;                                                          \
+                                                                       \
+       default:                                                        \
+               match_key = 0;                                          \
+               if (keycmp(bkt_key, pkt_key, key_mask, f->key_size) == 0)       \
+                       match_key = 1;                                  \
+       }                                                               \
 }
 
 #define lookup2_stage0(t, g, pkts, pkts_mask, pkt00_index, pkt01_index)\
@@ -619,20 +686,20 @@ static int rte_table_hash_lru_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];                          \
                                                                \
index 13d309d..3c48640 100644 (file)
@@ -204,14 +204,15 @@ app_main_loop_worker_pipeline_hash(void) {
        case e_APP_PIPELINE_HASH_KEY16_LRU:
        case e_APP_PIPELINE_HASH_KEY32_LRU:
        {
-               struct rte_table_hash_lru_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,
-                       .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 = {