Re: [dpdk-dev] [PATCH v2] net/mlx5: introduce mlx5 hash list

[Bing Zhao <bingz@mellanox.com>]

Adding Stephen

Hi Stephen, would you please help to review the V2?
Many thanks in advance. :-)

BR. Bing

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Bing Zhao
> Sent: Wednesday, November 6, 2019 9:08 PM
> To: Slava Ovsiienko <viacheslavo@mellanox.com>; dev@dpdk.org
> Cc: Ori Kam <orika@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>
> Subject: [dpdk-dev] [PATCH v2] net/mlx5: introduce mlx5 hash list
> 
> Introduce simple hash list to the mlx5 utilities. User can define its own
> data structure containing the mlx5_hlist_entry and create the hash list
> table via the creation interface. Then the entry will be inserted into the
> table and linked to the corresponding list head. User should guarantee
> there is no collision of the key and provide a callback function to handle
> all the remaining entries in the table when destroying the hash list.
> User should define a proper number of the list heads in the table in
> order to get a better performance. The LSB of the 'key' is used to
> calculate the index of the head in the list heads array.
> This implementation is not multi-threads safe right now.
> 
> Signed-off-by: Bing Zhao <bingz@mellanox.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---
>  drivers/net/mlx5/Makefile     |   1 +
>  drivers/net/mlx5/meson.build  |   2 +
>  drivers/net/mlx5/mlx5_utils.c | 119
> ++++++++++++++++++++++++++++++++++++++++++
>  drivers/net/mlx5/mlx5_utils.h | 107
> ++++++++++++++++++++++++++++++++++++-
>  4 files changed, 227 insertions(+), 2 deletions(-)  create mode 100644
> drivers/net/mlx5/mlx5_utils.c
> 
> diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
> index dae5b9f..44cc26a 100644
> --- a/drivers/net/mlx5/Makefile
> +++ b/drivers/net/mlx5/Makefile
> @@ -37,6 +37,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) +=
> mlx5_flow_verbs.c
>  SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_mp.c
>  SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_nl.c
>  SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_devx_cmds.c
> +SRCS-$(CONFIG_RTE_LIBRTE_MLX5_PMD) += mlx5_utils.c
> 
>  ifeq ($(CONFIG_RTE_IBVERBS_LINK_DLOPEN),y)
>  INSTALL-$(CONFIG_RTE_LIBRTE_MLX5_PMD)-lib += $(LIB_GLUE) diff -
> -git a/drivers/net/mlx5/meson.build b/drivers/net/mlx5/meson.build
> index 02494cf..b72ddb4 100644
> --- a/drivers/net/mlx5/meson.build
> +++ b/drivers/net/mlx5/meson.build
> @@ -38,6 +38,7 @@ endforeach
> 
>  if build
>  	allow_experimental_apis = true
> +	deps += ['hash']
>  	ext_deps += libs
>  	sources = files(
>  		'mlx5.c',
> @@ -58,6 +59,7 @@ if build
>  		'mlx5_txq.c',
>  		'mlx5_vlan.c',
>  		'mlx5_devx_cmds.c',
> +		'mlx5_utils.c',
>  	)
>  	if (dpdk_conf.has('RTE_ARCH_X86_64')
>  		or dpdk_conf.has('RTE_ARCH_ARM64')
> diff --git a/drivers/net/mlx5/mlx5_utils.c
> b/drivers/net/mlx5/mlx5_utils.c new file mode 100644 index
> 0000000..5d86615
> --- /dev/null
> +++ b/drivers/net/mlx5/mlx5_utils.c
> @@ -0,0 +1,119 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2019 Mellanox Technologies, Ltd  */
> +
> +#include <rte_malloc.h>
> +#include <rte_hash_crc.h>
> +
> +#include "mlx5_utils.h"
> +
> +struct mlx5_hlist *
> +mlx5_hlist_create(const char *name, uint32_t size) {
> +	struct mlx5_hlist *h;
> +	uint32_t act_size;
> +	uint32_t alloc_size;
> +
> +	if (!size)
> +		return NULL;
> +	/* Align to the next power of 2, 32bits integer is enough now.
> */
> +	if (!rte_is_power_of_2(size)) {
> +		act_size = rte_align32pow2(size);
> +		DRV_LOG(WARNING, "Size 0x%" PRIX32 " is not power
> of 2, will "
> +			"be aligned to 0x%" PRIX32 ".\n", size, act_size);
> +	} else {
> +		act_size = size;
> +	}
> +	alloc_size = sizeof(struct mlx5_hlist) +
> +		     sizeof(struct mlx5_hlist_head) * act_size;
> +	/* Using zmalloc, then no need to initialize the heads. */
> +	h = rte_zmalloc(name, alloc_size, RTE_CACHE_LINE_SIZE);
> +	if (!h) {
> +		DRV_LOG(ERR, "No memory for hash list %s
> creation\n",
> +			name ? name : "None");
> +		return NULL;
> +	}
> +	if (name)
> +		snprintf(h->name, MLX5_HLIST_NAMESIZE, "%s",
> name);
> +	h->table_sz = act_size;
> +	h->mask = act_size - 1;
> +	DRV_LOG(DEBUG, "Hash list with %s size 0x%" PRIX32 " is
> created.\n",
> +		h->name, act_size);
> +	return h;
> +}
> +
> +struct mlx5_hlist_entry *
> +mlx5_hlist_lookup(struct mlx5_hlist *h, uint64_t key) {
> +	uint32_t idx;
> +	struct mlx5_hlist_head *first;
> +	struct mlx5_hlist_entry *node;
> +
> +	assert(h);
> +	idx = rte_hash_crc_8byte(key, 0) & h->mask;
> +	first = &h->heads[idx];
> +	LIST_FOREACH(node, first, next) {
> +		if (node->key == key)
> +			return node;
> +	}
> +	return NULL;
> +}
> +
> +int
> +mlx5_hlist_insert(struct mlx5_hlist *h, struct mlx5_hlist_entry *entry)
> +{
> +	uint32_t idx;
> +	struct mlx5_hlist_head *first;
> +	struct mlx5_hlist_entry *node;
> +
> +	assert(h && entry);
> +	idx = rte_hash_crc_8byte(entry->key, 0) & h->mask;
> +	first = &h->heads[idx];
> +	/* No need to reuse the lookup function. */
> +	LIST_FOREACH(node, first, next) {
> +		if (node->key == entry->key)
> +			return -EEXIST;
> +	}
> +	LIST_INSERT_HEAD(first, entry, next);
> +	return 0;
> +}
> +
> +void
> +mlx5_hlist_remove(struct mlx5_hlist *h __rte_unused,
> +		  struct mlx5_hlist_entry *entry)
> +{
> +	assert(entry && entry->next.le_prev);
> +	LIST_REMOVE(entry, next);
> +	/* Set to NULL to get rid of removing action for more than once.
> */
> +	entry->next.le_prev = NULL;
> +}
> +
> +void
> +mlx5_hlist_destroy(struct mlx5_hlist *h,
> +		   mlx5_hlist_destroy_callback_fn cb, void *ctx) {
> +	uint32_t idx;
> +	struct mlx5_hlist_entry *entry;
> +
> +	assert(h);
> +	for (idx = 0; idx < h->table_sz; ++idx) {
> +		/* no LIST_FOREACH_SAFE, using while instead */
> +		while (!LIST_EMPTY(&h->heads[idx])) {
> +			entry = LIST_FIRST(&h->heads[idx]);
> +			LIST_REMOVE(entry, next);
> +			/*
> +			 * The owner of whole element which contains
> data entry
> +			 * is the user, so it's the user's duty to do the
> clean
> +			 * up and the free work because someone may
> not put the
> +			 * hlist entry at the beginning(suggested to
> locate at
> +			 * the beginning). Or else the default free
> function
> +			 * will be used.
> +			 */
> +			if (cb)
> +				cb(entry, ctx);
> +			else
> +				rte_free(entry);
> +		}
> +	}
> +	rte_free(h);
> +}
> diff --git a/drivers/net/mlx5/mlx5_utils.h
> b/drivers/net/mlx5/mlx5_utils.h index 97092c7..b4ed8c6 100644
> --- a/drivers/net/mlx5/mlx5_utils.h
> +++ b/drivers/net/mlx5/mlx5_utils.h
> @@ -151,13 +151,13 @@
>  	snprintf(name, sizeof(name), __VA_ARGS__)
> 
>  /**
> - * Return nearest power of two above input value.
> + * Return logarithm of the nearest power of two above input value.
>   *
>   * @param v
>   *   Input value.
>   *
>   * @return
> - *   Nearest power of two above input value.
> + *   Logarithm of the nearest power of two above input value.
>   */
>  static inline unsigned int
>  log2above(unsigned int v)
> @@ -170,4 +170,107 @@
>  	return l + r;
>  }
> 
> +/** Maximum size of string for naming the hlist table. */
> +#define MLX5_HLIST_NAMESIZE			32
> +
> +/**
> + * Structure of the entry in the hash list, user should define its own
> +struct
> + * that contains this in order to store the data. The 'key' is 64-bits
> +right
> + * now and its user's responsibility to guarantee there is no collision.
> + */
> +struct mlx5_hlist_entry {
> +	LIST_ENTRY(mlx5_hlist_entry) next; /* entry pointers in the list.
> */
> +	uint64_t key; /* user defined 'key', could be the hash signature.
> */
> +};
> +
> +/** Structure for hash head. */
> +LIST_HEAD(mlx5_hlist_head, mlx5_hlist_entry);
> +
> +/** Type of function that is used to handle the data before freeing.
> */
> +typedef void (*mlx5_hlist_destroy_callback_fn)(void *p, void *ctx);
> +
> +/** hash list table structure */
> +struct mlx5_hlist {
> +	char name[MLX5_HLIST_NAMESIZE]; /**< Name of the hash
> list. */
> +	/**< number of heads, need to be power of 2. */
> +	uint32_t table_sz;
> +	/**< mask to get the index of the list heads. */
> +	uint32_t mask;
> +	struct mlx5_hlist_head heads[];	/**< list head arrays.
> */
> +};
> +
> +/**
> + * Create a hash list table, the user can specify the list heads array
> +size
> + * of the table, now the size should be a power of 2 in order to get
> +better
> + * distribution for the entries. Each entry is a part of the whole data
> +element
> + * and the caller should be responsible for the data element's
> +allocation and
> + * cleanup / free. Key of each entry will be calculated with CRC in
> +order to
> + * generate a little fairer distribution.
> + *
> + * @param name
> + *   Name of the hash list(optional).
> + * @param size
> + *   Heads array size of the hash list.
> + *
> + * @return
> + *   Pointer of the hash list table created, NULL on failure.
> + */
> +struct mlx5_hlist *mlx5_hlist_create(const char *name, uint32_t size);
> +
> +/**
> + * Search an entry matching the key.
> + *
> + * @param h
> + *   Pointer to the hast list table.
> + * @param key
> + *   Key for the searching entry.
> + *
> + * @return
> + *   Pointer of the hlist entry if found, NULL otherwise.
> + */
> +struct mlx5_hlist_entry *mlx5_hlist_lookup(struct mlx5_hlist *h,
> +uint64_t key);
> +
> +/**
> + * Insert an entry to the hash list table, the entry is only part of
> +whole data
> + * element and a 64B key is used for matching. User should construct
> +the key or
> + * give a calculated hash signature and guarantee there is no collision.
> + *
> + * @param h
> + *   Pointer to the hast list table.
> + * @param entry
> + *   Entry to be inserted into the hash list table.
> + *
> + * @return
> + *   - zero for success.
> + *   - -EEXIST if the entry is already inserted.
> + */
> +int mlx5_hlist_insert(struct mlx5_hlist *h, struct mlx5_hlist_entry
> +*entry);
> +
> +/**
> + * Remove an entry from the hash list table. User should guarantee
> the
> +validity
> + * of the entry.
> + *
> + * @param h
> + *   Pointer to the hast list table. (not used)
> + * @param entry
> + *   Entry to be removed from the hash list table.
> + */
> +void mlx5_hlist_remove(struct mlx5_hlist *h __rte_unused,
> +		       struct mlx5_hlist_entry *entry);
> +
> +/**
> + * Destroy the hash list table, all the entries already inserted into
> +the lists
> + * will be handled by the callback function provided by the user
> +(including
> + * free if needed) before the table is freed.
> + *
> + * @param h
> + *   Pointer to the hast list table.
> + * @param cb
> + *   Callback function for each inserted entry when destroying the
> hash list.
> + * @param ctx
> + *   Common context parameter used by callback function for each
> entry.
> + */
> +void mlx5_hlist_destroy(struct mlx5_hlist *h,
> +			mlx5_hlist_destroy_callback_fn cb, void *ctx);
> +
>  #endif /* RTE_PMD_MLX5_UTILS_H_ */
> --
> 1.8.3.1