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

[Slava Ovsiienko <viacheslavo@mellanox.com>]

> -----Original Message-----
> From: Bing Zhao <bingz@pegasus02.mtr.labs.mlnx>
> Sent: Tuesday, November 5, 2019 15:27
> To: Ori Kam <orika@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>; Raslan Darawsheh <rasland@mellanox.com>
> Cc: dev@dpdk.org; Bing Zhao <bingz@mellanox.com>
> Subject: [PATCH] net/mlx5: introdue mlx5 hash list
> 
> From: Bing Zhao <bingz@mellanox.com>
> 
> 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  |   1 +
>  drivers/net/mlx5/mlx5_utils.c | 126
> ++++++++++++++++++++++++++++++++++++++++++
>  drivers/net/mlx5/mlx5_utils.h | 106
> ++++++++++++++++++++++++++++++++++-
>  4 files changed, 232 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..344f109 100644
> --- a/drivers/net/mlx5/meson.build
> +++ b/drivers/net/mlx5/meson.build
> @@ -58,6 +58,7 @@ 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..0181f49
> --- /dev/null
> +++ b/drivers/net/mlx5/mlx5_utils.c
> @@ -0,0 +1,126 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2019 Mellanox Technologies, Ltd  */
> +
> +#include <rte_malloc.h>
> +
> +#include "mlx5_utils.h"
> +
> +struct mlx5_hlist *
> +mlx5_hlist_create(char *name, uint64_t size,
> +mlx5_hlist_destroy_callback_fn cb) {
> +	struct mlx5_hlist *h;
> +	uint64_t act_size;
> +	uint64_t alloc_size;
> +
> +	if (!size)
> +		return NULL;
> +	/* If the low 32B is power of 2, then the 64B integer is too. */
> +	if (!rte_is_power_of_2((uint32_t)size)) {
> +		act_size = rte_align64pow2(size);
> +		DRV_LOG(WARNING, "Size 0x%" PRIX64 " is not power of 2,
> will "
> +			"be aligned to 0x%" PRIX64 ".\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);
> +	if (!cb)
> +		DRV_LOG(WARNING, "No callback function is specified, will
> use "
> +			"rte_free when destroying hlist %p %s\n",
> +			(void *)h, h->name);
> +	else
> +		h->cb = cb;
> +	h->table_sz = act_size;
> +	h->mask = act_size - 1;
> +	DRV_LOG(DEBUG, "Hash list with %s size 0x%" PRIX64 ", callback "
> +		"0x%" PRIX64 "is created.\n",
> +		h->name, act_size, (uint64_t)(uintptr_t)cb);
> +	return h;
> +}
> +
> +struct mlx5_hlist_entry *
> +mlx5_hlist_lookup(struct mlx5_hlist *h, uint64_t key) {
> +	uint64_t idx;
> +	struct mlx5_hlist_head *first;
> +	struct mlx5_hlist_entry *node;
> +
> +	assert(h);
> +	idx = key & 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)
> +{
> +	uint64_t idx;
> +	struct mlx5_hlist_head *first;
> +	struct mlx5_hlist_entry *node;
> +
> +	assert(h && entry);
> +	idx = entry->key & 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) {
> +	uint64_t idx;
> +	struct mlx5_hlist_entry *entry;
> +	mlx5_hlist_destroy_callback_fn cb;
> +
> +	assert(h);
> +	cb = h->cb;
> +	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)
> +				h->cb(entry);
> +			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..81da50d 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 +170,106 @@
>  	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);
> +
> +/** 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. */
> +	uint64_t table_sz;
> +	/**< mask to get the index of the list heads. */
> +	uint64_t mask;
> +	/**< The callback function before free when destroying hash list. */
> +	mlx5_hlist_destroy_callback_fn cb;
> +	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.
> + *
> + * @param name
> + *   Name of the hash list(optional).
> + * @param size
> + *   Heads array size of the hash list.
> + * @param cb
> + *   Callback function for each inserted entries when destroying the hash list.
> + *
> + * @return
> + *   Pointer of the hash list table created, NULL on failure.
> + */
> +struct mlx5_hlist *mlx5_hlist_create(char *name, uint64_t size,
> +				     mlx5_hlist_destroy_callback_fn cb);
> +
> +/**
> + * 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.
> + */
> +void mlx5_hlist_destroy(struct mlx5_hlist *h);
> +
>  #endif /* RTE_PMD_MLX5_UTILS_H_ */
> --
> 1.8.3.1