Re: [dpdk-dev] [PATCH v4 1/4] hash: add kv hash library

["Wang, Yipeng1" <yipeng1.wang@intel.com>]

> -----Original Message-----
> From: Medvedkin, Vladimir <vladimir.medvedkin@intel.com>
> Sent: Friday, May 8, 2020 12:59 PM
> To: dev@dpdk.org
> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Wang, Yipeng1
> <yipeng1.wang@intel.com>; Gobriel, Sameh <sameh.gobriel@intel.com>;
> Richardson, Bruce <bruce.richardson@intel.com>
> Subject: [PATCH v4 1/4] hash: add kv hash library
> 
> KV hash is a special optimized key-value storage for fixed key and value sizes.
> At the moment it supports 32 bit keys and 64 bit values. This table is hash
> function agnostic so user must provide precalculated hash signature for
> add/delete/lookup operations.
> 
> Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> ---
>  lib/Makefile                           |   2 +-
>  lib/librte_hash/Makefile               |  14 +-
>  lib/librte_hash/k32v64_hash.c          | 277
> +++++++++++++++++++++++++++++++++
>  lib/librte_hash/k32v64_hash.h          |  98 ++++++++++++
>  lib/librte_hash/k32v64_hash_avx512vl.c |  59 +++++++
>  lib/librte_hash/meson.build            |  17 +-
>  lib/librte_hash/rte_hash_version.map   |   6 +-
>  lib/librte_hash/rte_kv_hash.c          | 184 ++++++++++++++++++++++
>  lib/librte_hash/rte_kv_hash.h          | 169 ++++++++++++++++++++
>  9 files changed, 821 insertions(+), 5 deletions(-)  create mode 100644
> lib/librte_hash/k32v64_hash.c  create mode 100644
> lib/librte_hash/k32v64_hash.h  create mode 100644
> lib/librte_hash/k32v64_hash_avx512vl.c
>  create mode 100644 lib/librte_hash/rte_kv_hash.c  create mode 100644
> lib/librte_hash/rte_kv_hash.h
> 
> diff --git a/lib/Makefile b/lib/Makefile index 9d24609..42769e9 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -48,7 +48,7 @@ DIRS-$(CONFIG_RTE_LIBRTE_VHOST) += librte_vhost
> DEPDIRS-librte_vhost := librte_eal librte_mempool librte_mbuf
> librte_ethdev \
>  			librte_net librte_hash librte_cryptodev
>  DIRS-$(CONFIG_RTE_LIBRTE_HASH) += librte_hash -DEPDIRS-librte_hash :=
> librte_eal librte_ring
> +DEPDIRS-librte_hash := librte_eal librte_ring librte_mempool
>  DIRS-$(CONFIG_RTE_LIBRTE_EFD) += librte_efd  DEPDIRS-librte_efd :=
> librte_eal librte_ring librte_hash
>  DIRS-$(CONFIG_RTE_LIBRTE_RIB) += librte_rib diff --git
> a/lib/librte_hash/Makefile b/lib/librte_hash/Makefile index
> ec9f864..a0cdee9 100644
> --- a/lib/librte_hash/Makefile
> +++ b/lib/librte_hash/Makefile
> @@ -8,13 +8,15 @@ LIB = librte_hash.a
> 
>  CFLAGS += -O3
>  CFLAGS += $(WERROR_FLAGS) -I$(SRCDIR)
> -LDLIBS += -lrte_eal -lrte_ring
> +LDLIBS += -lrte_eal -lrte_ring -lrte_mempool
> 
>  EXPORT_MAP := rte_hash_version.map
> 
>  # all source are stored in SRCS-y
>  SRCS-$(CONFIG_RTE_LIBRTE_HASH) := rte_cuckoo_hash.c
>  SRCS-$(CONFIG_RTE_LIBRTE_HASH) += rte_fbk_hash.c
> +SRCS-$(CONFIG_RTE_LIBRTE_HASH) += rte_kv_hash.c
> +SRCS-$(CONFIG_RTE_LIBRTE_HASH) += k32v64_hash.c
> 
>  # install this header file
>  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include := rte_hash.h @@ -27,5
> +29,15 @@ endif  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include +=
> rte_jhash.h  SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_thash.h
> SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_fbk_hash.h
> +SYMLINK-$(CONFIG_RTE_LIBRTE_HASH)-include += rte_kv_hash.h
> +
> +CC_AVX512VL_SUPPORT=$(shell $(CC) -mavx512vl -dM -E - </dev/null
> 2>&1 |
> +\ grep -q __AVX512VL__ && echo 1)
> +
> +ifeq ($(CC_AVX512VL_SUPPORT), 1)
> +	SRCS-$(CONFIG_RTE_LIBRTE_HASH) += k32v64_hash_avx512vl.c
> +	CFLAGS_k32v64_hash_avx512vl.o += -mavx512vl
> +	CFLAGS_k32v64_hash.o += -DCC_AVX512VL_SUPPORT endif
> 
>  include $(RTE_SDK)/mk/rte.lib.mk
> diff --git a/lib/librte_hash/k32v64_hash.c b/lib/librte_hash/k32v64_hash.c
> new file mode 100644 index 0000000..24cd63a
> --- /dev/null
> +++ b/lib/librte_hash/k32v64_hash.c
> @@ -0,0 +1,277 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#include <string.h>
> +
> +#include <rte_errno.h>
> +#include <rte_malloc.h>
> +#include <rte_memory.h>
> +
> +#include "k32v64_hash.h"
> +
> +static inline int
> +k32v64_hash_lookup(struct k32v64_hash_table *table, uint32_t key,
> +	uint32_t hash, uint64_t *value)
> +{
> +	return __k32v64_hash_lookup(table, key, hash, value,
> __kv_cmp_keys); }
> +
> +static int
> +k32v64_hash_bulk_lookup(struct rte_kv_hash_table *ht, void *keys_p,
> +	uint32_t *hashes, void *values_p, unsigned int n) {
> +	struct k32v64_hash_table *table = (struct k32v64_hash_table *)ht;
> +	uint32_t *keys = keys_p;
> +	uint64_t *values = values_p;
> +	int ret, cnt = 0;
> +	unsigned int i;
> +
> +	if (unlikely((table == NULL) || (keys == NULL) || (hashes == NULL) ||
> +			(values == NULL)))
> +		return -EINVAL;
> +
> +	for (i = 0; i < n; i++) {
> +		ret = k32v64_hash_lookup(table, keys[i], hashes[i],
> +			&values[i]);
[Wang, Yipeng] You don't need to start a new line for values.
> +		if (ret == 0)
> +			cnt++;
> +	}
> +	return cnt;
> +}
> +
> +#ifdef CC_AVX512VL_SUPPORT
[Wang, Yipeng] Why not use the already provided, e.g. #if defined(RTE_MACHINE_CPUFLAG_SSE2) like rte_hash does?
> +int
> +k32v64_hash_bulk_lookup_avx512vl(struct rte_kv_hash_table *ht,
> +	void *keys_p, uint32_t *hashes, void *values_p, unsigned int n);
> +#endif
> +
> +static rte_kv_hash_bulk_lookup_t
> +get_lookup_bulk_fn(void)
> +{
> +#ifdef CC_AVX512VL_SUPPORT
> +	if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_AVX512VL))
> +		return k32v64_hash_bulk_lookup_avx512vl; #endif
> +	return k32v64_hash_bulk_lookup;
> +}
> +
> +static int
> +k32v64_hash_add(struct k32v64_hash_table *table, uint32_t key,
> +	uint32_t hash, uint64_t value, uint64_t *old_value, int *found) {
> +	uint32_t bucket;
> +	int i, idx, ret;
> +	uint8_t msk;
> +	struct k32v64_ext_ent *tmp, *ent, *prev = NULL;
> +
> +	if (table == NULL)
> +		return -EINVAL;
> +
> +	bucket = hash & table->bucket_msk;
> +	/* Search key in table. Update value if exists */
> +	for (i = 0; i < K32V64_KEYS_PER_BUCKET; i++) {
> +		if ((key == table->t[bucket].key[i]) &&
> +				(table->t[bucket].key_mask & (1 << i))) {
> +			*old_value = table->t[bucket].val[i];
> +			*found = 1;
> +			__atomic_fetch_add(&table->t[bucket].cnt, 1,
> +				__ATOMIC_ACQUIRE);
> +			table->t[bucket].val[i] = value;
> +			__atomic_fetch_add(&table->t[bucket].cnt, 1,
> +				__ATOMIC_RELEASE);
> +			return 0;
> +		}
> +	}
> +
> +	if (!SLIST_EMPTY(&table->t[bucket].head)) {
> +		SLIST_FOREACH(ent, &table->t[bucket].head, next) {
> +			if (ent->key == key) {
> +				*old_value = ent->val;
> +				*found = 1;
> +				__atomic_fetch_add(&table->t[bucket].cnt,
> 1,
> +					__ATOMIC_ACQUIRE);
> +				ent->val = value;
> +				__atomic_fetch_add(&table->t[bucket].cnt,
> 1,
> +					__ATOMIC_RELEASE);
> +				return 0;
> +			}
> +		}
> +	}
> +
> +	msk = ~table->t[bucket].key_mask & VALID_KEY_MSK;
> +	if (msk) {
> +		idx = __builtin_ctz(msk);
> +		table->t[bucket].key[idx] = key;
> +		table->t[bucket].val[idx] = value;
> +		__atomic_or_fetch(&table->t[bucket].key_mask, 1 << idx,
> +			__ATOMIC_RELEASE);
> +		table->nb_ent++;
> +		*found = 0;
> +		return 0;
> +	}
> +
> +	ret = rte_mempool_get(table->ext_ent_pool, (void **)&ent);
> +	if (ret < 0)
> +		return ret;
> +
> +	SLIST_NEXT(ent, next) = NULL;
> +	ent->key = key;
> +	ent->val = value;
> +	rte_smp_wmb();
> +	SLIST_FOREACH(tmp, &table->t[bucket].head, next)
> +		prev = tmp;
> +
> +	if (prev == NULL)
> +		SLIST_INSERT_HEAD(&table->t[bucket].head, ent, next);
> +	else
> +		SLIST_INSERT_AFTER(prev, ent, next);
> +
> +	table->nb_ent++;
> +	table->nb_ext_ent++;
> +	*found = 0;
> +	return 0;
> +}
> +
> +static int
> +k32v64_hash_delete(struct k32v64_hash_table *table, uint32_t key,
> +	uint32_t hash, uint64_t *old_value)
> +{
> +	uint32_t bucket;
> +	int i;
> +	struct k32v64_ext_ent *ent;
> +
> +	if (table == NULL)
> +		return -EINVAL;
> +
> +	bucket = hash & table->bucket_msk;
> +
> +	for (i = 0; i < K32V64_KEYS_PER_BUCKET; i++) {
> +		if ((key == table->t[bucket].key[i]) &&
> +				(table->t[bucket].key_mask & (1 << i))) {
> +			*old_value = table->t[bucket].val[i];
> +			ent = SLIST_FIRST(&table->t[bucket].head);
> +			if (ent) {
> +				__atomic_fetch_add(&table->t[bucket].cnt,
> 1,
> +					__ATOMIC_ACQUIRE);
> +				table->t[bucket].key[i] = ent->key;
> +				table->t[bucket].val[i] = ent->val;
> +				SLIST_REMOVE_HEAD(&table-
> >t[bucket].head, next);
> +				__atomic_fetch_add(&table->t[bucket].cnt,
> 1,
> +					__ATOMIC_RELEASE);
> +				table->nb_ext_ent--;
> +			} else
> +				__atomic_and_fetch(&table-
> >t[bucket].key_mask,
> +					~(1 << i), __ATOMIC_RELEASE);
> +			if (ent)
> +				rte_mempool_put(table->ext_ent_pool,
> ent);
> +			table->nb_ent--;
> +			return 0;
> +		}
> +	}
> +
> +	SLIST_FOREACH(ent, &table->t[bucket].head, next)
> +		if (ent->key == key)
> +			break;
> +
> +	if (ent == NULL)
> +		return -ENOENT;
> +
> +	*old_value = ent->val;
> +
> +	__atomic_fetch_add(&table->t[bucket].cnt, 1,
> __ATOMIC_ACQUIRE);
> +	SLIST_REMOVE(&table->t[bucket].head, ent, k32v64_ext_ent, next);
> +	__atomic_fetch_add(&table->t[bucket].cnt, 1, __ATOMIC_RELEASE);
> +	rte_mempool_put(table->ext_ent_pool, ent);
> +
[Wang, Yipeng] I am not sure if delete can be called safely with other lookup threads.
The item could be recycled to be used by another add while a lookup thread traversing the linked list.
This is similar to why we need the RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL flag and related API in rte_hash.
> +	table->nb_ext_ent--;
> +	table->nb_ent--;
> +
> +	return 0;
> +}
> +
> +static int
> +k32v64_modify(struct rte_kv_hash_table *table, void *key_p, uint32_t
> hash,
> +	enum rte_kv_modify_op op, void *value_p, int *found) {
> +	struct k32v64_hash_table *ht = (struct k32v64_hash_table *)table;
> +	uint32_t *key = key_p;
> +	uint64_t value;
> +
> +	if ((ht == NULL) || (key == NULL) || (value_p == NULL) ||
> +			(found == NULL) || (op >=
> RTE_KV_MODIFY_OP_MAX)) {
> +		return -EINVAL;
> +	}
> +
> +	value = *(uint64_t *)value_p;
> +	switch (op) {
> +	case RTE_KV_MODIFY_ADD:
> +		return k32v64_hash_add(ht, *key, hash, value, value_p,
> found);
> +	case RTE_KV_MODIFY_DEL:
> +		return k32v64_hash_delete(ht, *key, hash, value_p);
> +	default:
> +		break;
> +	}
[Wang, Yipeng] A question would be why put del and add inside another mod wrapper.
If we don't wrap del and add like this, we could get rid of this branch.
> +
> +	return -EINVAL;
> +}
> +
> +struct rte_kv_hash_table *
> +k32v64_hash_create(const struct rte_kv_hash_params *params) {
> +	char hash_name[RTE_KV_HASH_NAMESIZE];
> +	struct k32v64_hash_table *ht = NULL;
> +	uint32_t mem_size, nb_buckets, max_ent;
> +	int ret;
> +	struct rte_mempool *mp;
> +
> +	if ((params == NULL) || (params->name == NULL) ||
> +			(params->entries == 0)) {
[Wang, Yipeng] Should we check if entry count larger than keys_per_bucket as well?
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +
> +	ret = snprintf(hash_name, sizeof(hash_name), "KV_%s", params-
> >name);
> +	if (ret < 0 || ret >= RTE_KV_HASH_NAMESIZE) {
> +		rte_errno = ENAMETOOLONG;
> +		return NULL;
> +	}
> +
> +	max_ent = rte_align32pow2(params->entries);
> +	nb_buckets = max_ent / K32V64_KEYS_PER_BUCKET;
[Wang, Yipeng] Macro to check if keys_per_bucket need to be power of 2
> +	mem_size = sizeof(struct k32v64_hash_table) +
> +		sizeof(struct k32v64_hash_bucket) * nb_buckets;
> +
> +	mp = rte_mempool_create(hash_name, max_ent,
> +		sizeof(struct k32v64_ext_ent), 0, 0, NULL, NULL, NULL, NULL,
> +		params->socket_id, 0);
> +
> +	if (mp == NULL)
> +		return NULL;
> +
> +	ht = rte_zmalloc_socket(hash_name, mem_size,
> +		RTE_CACHE_LINE_SIZE, params->socket_id);
> +	if (ht == NULL) {
> +		rte_mempool_free(mp);
> +		return NULL;
> +	}
> +
> +	memcpy(ht->pub.name, hash_name, sizeof(ht->pub.name));
> +	ht->max_ent = max_ent;
> +	ht->bucket_msk = nb_buckets - 1;
> +	ht->ext_ent_pool = mp;
> +	ht->pub.lookup = get_lookup_bulk_fn();
[Wang, Yipeng] Inside the function, we also need to check the CPUID during runtime to decide if AVX can be used, not only compile time.
You could refer to example from rte_hash: ... if (rte_cpu_get_flag_enabled(RTE_CPUFLAG_SSE2)) ...

> +	ht->pub.modify = k32v64_modify;
> +
> +	return (struct rte_kv_hash_table *)ht; }
> +
> +void
> +k32v64_hash_free(struct rte_kv_hash_table *ht) {
> +	if (ht == NULL)
> +		return;
> +
> +	rte_mempool_free(((struct k32v64_hash_table *)ht)-
> >ext_ent_pool);
> +	rte_free(ht);
> +}
> diff --git a/lib/librte_hash/k32v64_hash.h b/lib/librte_hash/k32v64_hash.h
> new file mode 100644 index 0000000..10061a5
> --- /dev/null
> +++ b/lib/librte_hash/k32v64_hash.h
> @@ -0,0 +1,98 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#include <rte_kv_hash.h>
> +
> +#define K32V64_KEYS_PER_BUCKET		4
> +#define K32V64_WRITE_IN_PROGRESS	1
> +#define VALID_KEY_MSK           ((1 << K32V64_KEYS_PER_BUCKET) - 1)
> +
> +struct k32v64_ext_ent {
> +	SLIST_ENTRY(k32v64_ext_ent) next;
> +	uint32_t	key;
> +	uint64_t	val;
> +};
> +
> +struct k32v64_hash_bucket {
> +	uint32_t	key[K32V64_KEYS_PER_BUCKET];
> +	uint64_t	val[K32V64_KEYS_PER_BUCKET];
> +	uint8_t		key_mask;
> +	uint32_t	cnt;
> +	SLIST_HEAD(k32v64_list_head, k32v64_ext_ent) head; }
> +__rte_cache_aligned;
> +
> +struct k32v64_hash_table {
> +	struct rte_kv_hash_table pub;	/**< Public part */
[Wang, Yipeng] Do we need to have the pub filed? Could we just init the public part in the public create function?
> +	uint32_t	nb_ent;		/**< Number of entities in
> the table*/
> +	uint32_t	nb_ext_ent;	/**< Number of extended entities */
> +	uint32_t	max_ent;	/**< Maximum number of entities */
> +	uint32_t	bucket_msk;
> +	struct rte_mempool	*ext_ent_pool;
> +	__extension__ struct k32v64_hash_bucket	t[0];
> +};
> +
> +typedef int (*k32v64_cmp_fn_t)
> +(struct k32v64_hash_bucket *bucket, uint32_t key, uint64_t *val);
> +
> +static inline int
> +__kv_cmp_keys(struct k32v64_hash_bucket *bucket, uint32_t key,
> +	uint64_t *val)
> +{
> +	int i;
> +
> +	for (i = 0; i < K32V64_KEYS_PER_BUCKET; i++) {
> +		if ((key == bucket->key[i]) &&
> +				(bucket->key_mask & (1 << i))) {
> +			*val = bucket->val[i];
> +			return 1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static inline int
> +__k32v64_hash_lookup(struct k32v64_hash_table *table, uint32_t key,
> +	uint32_t hash, uint64_t *value, k32v64_cmp_fn_t cmp_f) {
> +	uint64_t	val = 0;
> +	struct k32v64_ext_ent *ent;
> +	uint32_t	cnt;
> +	int found = 0;
> +	uint32_t bucket = hash & table->bucket_msk;
> +
> +	do {
> +
> +		do {
> +			cnt = __atomic_load_n(&table->t[bucket].cnt,
> +				__ATOMIC_ACQUIRE);
> +		} while (unlikely(cnt & K32V64_WRITE_IN_PROGRESS));
> +
> +		found = cmp_f(&table->t[bucket], key, &val);
> +		if (unlikely((found == 0) &&
> +				(!SLIST_EMPTY(&table->t[bucket].head)))) {
> +			SLIST_FOREACH(ent, &table->t[bucket].head, next) {
> +				if (ent->key == key) {
> +					val = ent->val;
> +					found = 1;
> +					break;
> +				}
> +			}
> +		}
> +		__atomic_thread_fence(__ATOMIC_RELEASE);
> +	} while (unlikely(cnt != __atomic_load_n(&table->t[bucket].cnt,
> +			 __ATOMIC_RELAXED)));
> +
> +	if (found == 1) {
> +		*value = val;
> +		return 0;
> +	} else
> +		return -ENOENT;
> +}
> +
> +struct rte_kv_hash_table *
> +k32v64_hash_create(const struct rte_kv_hash_params *params);
> +
> +void
> +k32v64_hash_free(struct rte_kv_hash_table *ht);
> diff --git a/lib/librte_hash/k32v64_hash_avx512vl.c
> b/lib/librte_hash/k32v64_hash_avx512vl.c
> new file mode 100644
> index 0000000..75cede5
> --- /dev/null
> +++ b/lib/librte_hash/k32v64_hash_avx512vl.c
> @@ -0,0 +1,59 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#include "k32v64_hash.h"
> +
> +int
> +k32v64_hash_bulk_lookup_avx512vl(struct rte_kv_hash_table *ht, void
> *keys_p,
> +	uint32_t *hashes, void *values_p, unsigned int n);
> +
> +static inline int
> +k32v64_cmp_keys_avx512vl(struct k32v64_hash_bucket *bucket, uint32_t
> key,
> +	uint64_t *val)
> +{
> +	__m128i keys, srch_key;
> +	__mmask8 msk;
> +
> +	keys = _mm_load_si128((void *)bucket);
> +	srch_key = _mm_set1_epi32(key);
> +
> +	msk = _mm_mask_cmpeq_epi32_mask(bucket->key_mask, keys,
> srch_key);
> +	if (msk) {
> +		*val = bucket->val[__builtin_ctz(msk)];
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static inline int
> +k32v64_hash_lookup_avx512vl(struct k32v64_hash_table *table, uint32_t
> key,
> +	uint32_t hash, uint64_t *value)
> +{
> +	return __k32v64_hash_lookup(table, key, hash, value,
> +		k32v64_cmp_keys_avx512vl);
> +}
> +
> +int
> +k32v64_hash_bulk_lookup_avx512vl(struct rte_kv_hash_table *ht, void
> *keys_p,
> +	uint32_t *hashes, void *values_p, unsigned int n) {
> +	struct k32v64_hash_table *table = (struct k32v64_hash_table *)ht;
> +	uint32_t *keys = keys_p;
> +	uint64_t *values = values_p;
> +	int ret, cnt = 0;
> +	unsigned int i;
> +
> +	if (unlikely((table == NULL) || (keys == NULL) || (hashes == NULL) ||
> +			(values == NULL)))
> +		return -EINVAL;
> +
> +	for (i = 0; i < n; i++) {
> +		ret = k32v64_hash_lookup_avx512vl(table, keys[i], hashes[i],
> +			&values[i]);
> +		if (ret == 0)
> +			cnt++;
> +	}
> +	return cnt;
> +}
> diff --git a/lib/librte_hash/meson.build b/lib/librte_hash/meson.build index
> 6ab46ae..0d014ea 100644
> --- a/lib/librte_hash/meson.build
> +++ b/lib/librte_hash/meson.build
> @@ -3,10 +3,23 @@
> 
>  headers = files('rte_crc_arm64.h',
>  	'rte_fbk_hash.h',
> +	'rte_kv_hash.h',
>  	'rte_hash_crc.h',
>  	'rte_hash.h',
>  	'rte_jhash.h',
>  	'rte_thash.h')
> 
> -sources = files('rte_cuckoo_hash.c', 'rte_fbk_hash.c') -deps += ['ring']
> +sources = files('rte_cuckoo_hash.c', 'rte_fbk_hash.c', 'rte_kv_hash.c',
> +'k32v64_hash.c') deps += ['ring', 'mempool']
> +
> +if dpdk_conf.has('RTE_ARCH_X86')
> +	if cc.has_argument('-mavx512vl')
> +		avx512_tmplib = static_library('avx512_tmp',
> +                                'k32v64_hash_avx512vl.c',
> +                                dependencies: static_rte_mempool,
> +                                c_args: cflags + ['-mavx512vl'])
> +                objs += avx512_tmplib.extract_objects('k32v64_hash_avx512vl.c')
> +                cflags += '-DCC_AVX512VL_SUPPORT'
> +
> +	endif
> +endif
> diff --git a/lib/librte_hash/rte_hash_version.map
> b/lib/librte_hash/rte_hash_version.map
> index c2a9094..614e0a5 100644
> --- a/lib/librte_hash/rte_hash_version.map
> +++ b/lib/librte_hash/rte_hash_version.map
> @@ -36,5 +36,9 @@ EXPERIMENTAL {
>  	rte_hash_lookup_with_hash_bulk;
>  	rte_hash_lookup_with_hash_bulk_data;
>  	rte_hash_max_key_id;
> -
> +	rte_kv_hash_create;
> +	rte_kv_hash_find_existing;
> +	rte_kv_hash_free;
> +	rte_kv_hash_add;
> +	rte_kv_hash_delete;
>  };
> diff --git a/lib/librte_hash/rte_kv_hash.c b/lib/librte_hash/rte_kv_hash.c
> new file mode 100644 index 0000000..03df8db
> --- /dev/null
> +++ b/lib/librte_hash/rte_kv_hash.c
> @@ -0,0 +1,184 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#include <string.h>
> +
> +#include <rte_eal_memconfig.h>
> +#include <rte_errno.h>
> +#include <rte_malloc.h>
> +#include <rte_memory.h>
> +#include <rte_tailq.h>
> +
> +#include <rte_kv_hash.h>
[Wang, Yipeng] I think for this header we should use quotes ""
> +#include "k32v64_hash.h"
> +
> +TAILQ_HEAD(rte_kv_hash_list, rte_tailq_entry);
> +
> +static struct rte_tailq_elem rte_kv_hash_tailq = {
> +	.name = "RTE_KV_HASH",
> +};
> +
> +EAL_REGISTER_TAILQ(rte_kv_hash_tailq);
> +
> +int
> +rte_kv_hash_add(struct rte_kv_hash_table *table, void *key,
> +	uint32_t hash, void *value, int *found) {
> +	if (table == NULL)
[Wang, Yipeng] To be more consistent,
 I think we should either also check key/value/found here, or just not checking at all and leave it to the next functions.
> +		return -EINVAL;
> +
> +	return table->modify(table, key, hash, RTE_KV_MODIFY_ADD,
> +		value, found);
> +}
> +
> +int
> +rte_kv_hash_delete(struct rte_kv_hash_table *table, void *key,
> +	uint32_t hash, void *value)
> +{
> +	int found;
> +
> +	if (table == NULL)
> +		return -EINVAL;
> +
> +	return table->modify(table, key, hash, RTE_KV_MODIFY_DEL,
> +		value, &found);
> +}
> +
> +struct rte_kv_hash_table *
> +rte_kv_hash_find_existing(const char *name) {
> +	struct rte_kv_hash_table *h = NULL;
> +	struct rte_tailq_entry *te;
> +	struct rte_kv_hash_list *kv_hash_list;
> +
> +	kv_hash_list = RTE_TAILQ_CAST(rte_kv_hash_tailq.head,
> +			rte_kv_hash_list);
> +
> +	rte_mcfg_tailq_read_lock();
> +	TAILQ_FOREACH(te, kv_hash_list, next) {
> +		h = (struct rte_kv_hash_table *) te->data;
> +		if (strncmp(name, h->name, RTE_KV_HASH_NAMESIZE) == 0)
> +			break;
> +	}
> +	rte_mcfg_tailq_read_unlock();
> +	if (te == NULL) {
> +		rte_errno = ENOENT;
> +		return NULL;
> +	}
> +	return h;
> +}
> +
> +struct rte_kv_hash_table *
> +rte_kv_hash_create(const struct rte_kv_hash_params *params) {
> +	char hash_name[RTE_KV_HASH_NAMESIZE];
> +	struct rte_kv_hash_table *ht, *tmp_ht = NULL;
> +	struct rte_tailq_entry *te;
> +	struct rte_kv_hash_list *kv_hash_list;
> +	int ret;
> +
> +	if ((params == NULL) || (params->name == NULL) ||
> +			(params->entries == 0) ||
> +			(params->type >= RTE_KV_HASH_MAX)) {
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +
> +	kv_hash_list = RTE_TAILQ_CAST(rte_kv_hash_tailq.head,
> +		rte_kv_hash_list);
> +
> +	ret = snprintf(hash_name, sizeof(hash_name), "KV_%s", params-
> >name);
> +	if (ret < 0 || ret >= RTE_KV_HASH_NAMESIZE) {
> +		rte_errno = ENAMETOOLONG;
> +		return NULL;
> +	}
> +
> +	switch (params->type) {
> +	case RTE_KV_HASH_K32V64:
> +		ht = k32v64_hash_create(params);
> +		break;
> +	default:
> +		rte_errno = EINVAL;
> +		return NULL;
> +	}
> +	if (ht == NULL)
> +		return ht;
> +
> +	rte_mcfg_tailq_write_lock();
> +	TAILQ_FOREACH(te, kv_hash_list, next) {
> +		tmp_ht = (struct rte_kv_hash_table *) te->data;
> +		if (strncmp(params->name, tmp_ht->name,
> +				RTE_KV_HASH_NAMESIZE) == 0)
> +			break;
> +	}
> +	if (te != NULL) {
> +		rte_errno = EEXIST;
> +		goto exit;
> +	}
> +
> +	te = rte_zmalloc("KV_HASH_TAILQ_ENTRY", sizeof(*te), 0);
> +	if (te == NULL) {
> +		RTE_LOG(ERR, HASH, "Failed to allocate tailq entry\n");
> +		goto exit;
> +	}
> +
> +	ht->type = params->type;
> +	te->data = (void *)ht;
> +	TAILQ_INSERT_TAIL(kv_hash_list, te, next);
> +
> +	rte_mcfg_tailq_write_unlock();
> +
> +	return ht;
> +
> +exit:
> +	rte_mcfg_tailq_write_unlock();
> +	switch (params->type) {
> +	case RTE_KV_HASH_K32V64:
> +		k32v64_hash_free(ht);
> +		break;
> +	default:
> +		break;
> +	}
> +	return NULL;
> +}
> +
> +void
> +rte_kv_hash_free(struct rte_kv_hash_table *ht) {
> +	struct rte_tailq_entry *te;
> +	struct rte_kv_hash_list *kv_hash_list;
> +
> +	if (ht == NULL)
> +		return;
> +
> +	kv_hash_list = RTE_TAILQ_CAST(rte_kv_hash_tailq.head,
> +				rte_kv_hash_list);
> +
> +	rte_mcfg_tailq_write_lock();
> +
> +	/* find out tailq entry */
> +	TAILQ_FOREACH(te, kv_hash_list, next) {
> +		if (te->data == (void *) ht)
> +			break;
> +	}
> +
> +
> +	if (te == NULL) {
> +		rte_mcfg_tailq_write_unlock();
> +		return;
> +	}
> +
> +	TAILQ_REMOVE(kv_hash_list, te, next);
> +
> +	rte_mcfg_tailq_write_unlock();
> +
> +	switch (ht->type) {
> +	case RTE_KV_HASH_K32V64:
> +		k32v64_hash_free(ht);
> +		break;
> +	default:
> +		break;
> +	}
> +	rte_free(te);
> +}
> diff --git a/lib/librte_hash/rte_kv_hash.h b/lib/librte_hash/rte_kv_hash.h
> new file mode 100644 index 0000000..c0375d1
> --- /dev/null
> +++ b/lib/librte_hash/rte_kv_hash.h
> @@ -0,0 +1,169 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Intel Corporation
> + */
> +
> +#ifndef _RTE_KV_HASH_H_
> +#define _RTE_KV_HASH_H_
> +
> +#ifdef __cplusplus
> +extern "C" {
> +#endif
> +
> +#include <rte_compat.h>
> +#include <rte_atomic.h>
> +#include <rte_mempool.h>
> +
> +#define RTE_KV_HASH_NAMESIZE		32
> +
> +enum rte_kv_hash_type {
> +	RTE_KV_HASH_K32V64,
> +	RTE_KV_HASH_MAX
> +};
> +
> +enum rte_kv_modify_op {
> +	RTE_KV_MODIFY_ADD,
> +	RTE_KV_MODIFY_DEL,
> +	RTE_KV_MODIFY_OP_MAX
> +};
[Wang, Yipeng] Again, any particular reason that you combine add and del into an additional struct mod?
> +
> +struct rte_kv_hash_params {
> +	const char *name;
> +	uint32_t entries;
> +	int socket_id;
> +	enum rte_kv_hash_type type;
> +};
> +
> +struct rte_kv_hash_table;
> +
> +typedef int (*rte_kv_hash_bulk_lookup_t) (struct rte_kv_hash_table
> +*table, void *keys, uint32_t *hashes,
> +	void *values, unsigned int n);
> +
> +typedef int (*rte_kv_hash_modify_t)
> +(struct rte_kv_hash_table *table, void *key, uint32_t hash,
> +	enum rte_kv_modify_op op, void *value, int *found);
> +
> +struct rte_kv_hash_table {
> +	char name[RTE_KV_HASH_NAMESIZE];	/**< Name of the
> hash. */
> +	rte_kv_hash_bulk_lookup_t	lookup;
> +	rte_kv_hash_modify_t		modify;
> +	enum rte_kv_hash_type		type;
> +};
> +
> +/**
> + * Lookup bulk of keys.
> + * This function is multi-thread safe with regarding to other lookup threads.
> + *
> + * @param table
> + *   Hash table to add the key to.
> + * @param keys
> + *   Pointer to array of keys
> + * @param hashes
> + *   Pointer to array of hash values associated with keys.
> + * @param values
> + *   Pointer to array of value corresponded to keys
> + *   If the key was not found the corresponding value remains intact.
> + * @param n
> + *   Number of keys to lookup in batch.
> + * @return
> + *   -EINVAL if there's an error, otherwise number of successful lookups.
> + */
[Wang, Yipeng] experimental tag
> +static inline int
> +rte_kv_hash_bulk_lookup(struct rte_kv_hash_table *table,
> +	void *keys, uint32_t *hashes, void *values, unsigned int n) {
> +	return table->lookup(table, keys, hashes, values, n); }
> +
> +/**
> + * Add a key to an existing hash table with hash value.
> + * This operation is not multi-thread safe regarding to add/delete
> +functions
> + * and should only be called from one thread.
> + * However it is safe to call it along with lookup.
> + *
> + * @param table
> + *   Hash table to add the key to.
> + * @param key
> + *   Key to add to the hash table.
> + * @param value
> + *   Value to associate with key.
> + * @param hash
> + *   Hash value associated with key.
> + * @found
> + *   0 if no previously added key was found
> + *   1 previously added key was found, old value associated with the key
> + *   was written to *value
> + * @return
> + *   0 if ok, or negative value on error.
> + */
> +__rte_experimental
> +int
> +rte_kv_hash_add(struct rte_kv_hash_table *table, void *key,
> +	uint32_t hash, void *value, int *found);
> +
> +/**
> + * Remove a key with a given hash value from an existing hash table.
> + * This operation is not multi-thread safe regarding to add/delete
> +functions
> + * and should only be called from one thread.
> + * However it is safe to call it along with lookup.
> + *
> + * @param table
> + *   Hash table to remove the key from.
> + * @param key
> + *   Key to remove from the hash table.
> + * @param hash
> + *   hash value associated with key.
> + * @param value
> + *   pointer to memory where the old value will be written to on success
> + * @return
> + *   0 if ok, or negative value on error.
> + */
> +__rte_experimental
> +int
> +rte_kv_hash_delete(struct rte_kv_hash_table *table, void *key,
> +	uint32_t hash, void *value);
> +
> +/**
> + * Performs a lookup for an existing hash table, and returns a pointer
> +to
> + * the table if found.
> + *
> + * @param name
> + *   Name of the hash table to find
> + *
> + * @return
> + *   pointer to hash table structure or NULL on error with rte_errno
> + *   set appropriately.
> + */
> +__rte_experimental
> +struct rte_kv_hash_table *
> +rte_kv_hash_find_existing(const char *name);
> +
> +/**
> + * Create a new hash table for use with four byte keys.
[Wang, Yipeng] inaccurate comment, not four byte keys
> + *
> + * @param params
> + *   Parameters used in creation of hash table.
> + *
> + * @return
> + *   Pointer to hash table structure that is used in future hash table
> + *   operations, or NULL on error with rte_errno set appropriately.
> + */
> +__rte_experimental
> +struct rte_kv_hash_table *
> +rte_kv_hash_create(const struct rte_kv_hash_params *params);
> +
> +/**
> + * Free all memory used by a hash table.
> + *
> + * @param table
> + *   Hash table to deallocate.
> + */
> +__rte_experimental
> +void
> +rte_kv_hash_free(struct rte_kv_hash_table *table);
> +
> +#ifdef __cplusplus
> +}
> +#endif
> +
> +#endif /* _RTE_KV_HASH_H_ */
> --
> 2.7.4