Re: [dpdk-dev] [PATCH] ipsec: use hash lookup with hash sigs in sad lookup

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

Hi Vladimir,

> Change hash function from jhash to crc.
> Precalculate hash signatures for a bulk of keys and then
> use rte_hash_lookup_with_hash_bulk_data() to speed up sad lookup

Looks good in general.
Few thoughts below, nothing major.
 
> Signed-off-by: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> ---
> This patch depends on https://patches.dpdk.org/patch/66460/
> 
>  lib/librte_ipsec/ipsec_sad.c | 38 +++++++++++++++++++++++++++++---------
>  1 file changed, 29 insertions(+), 9 deletions(-)
> 
> diff --git a/lib/librte_ipsec/ipsec_sad.c b/lib/librte_ipsec/ipsec_sad.c
> index 2c994ed..3292968 100644
> --- a/lib/librte_ipsec/ipsec_sad.c
> +++ b/lib/librte_ipsec/ipsec_sad.c
> @@ -2,10 +2,12 @@
>   * Copyright(c) 2019 Intel Corporation
>   */
> 
> +#include <string.h>
> +
>  #include <rte_eal_memconfig.h>
>  #include <rte_errno.h>
>  #include <rte_hash.h>
> -#include <rte_jhash.h>
> +#include <rte_hash_crc.h>
>  #include <rte_malloc.h>
>  #include <rte_random.h>
>  #include <rte_rwlock.h>
> @@ -24,7 +26,7 @@
>  /* "SAD_<name>" */
>  #define SAD_FORMAT		SAD_PREFIX "%s"
> 
> -#define DEFAULT_HASH_FUNC	rte_jhash
> +#define DEFAULT_HASH_FUNC	rte_hash_crc
>  #define MIN_HASH_ENTRIES	8U /* From rte_cuckoo_hash.h */
> 
>  struct hash_cnt {
> @@ -35,6 +37,9 @@ struct hash_cnt {
>  struct rte_ipsec_sad {
>  	char name[RTE_IPSEC_SAD_NAMESIZE];
>  	struct rte_hash	*hash[RTE_IPSEC_SAD_KEY_TYPE_MASK];
> +	uint32_t spi_dip_keysize;
> +	uint32_t spi_dip_sip_keysize;

Pure stylish thing: might be
uint32_t keysize[RTE_IPSEC_SAD_KEY_TYPE_MASK];
here?

> +	uint32_t init_val;
>  	/* Array to track number of more specific rules
>  	 * (spi_dip or spi_dip_sip). Used only in add/delete
>  	 * as a helper struct.
> @@ -272,6 +277,7 @@ rte_ipsec_sad_create(const char *name, const struct rte_ipsec_sad_conf *conf)
> 
>  	hash_params.hash_func = DEFAULT_HASH_FUNC;

If we doing lookup_with_hash now, might be it makes sense to
do add_with_hash and del_with_hash too?
For code consistency.

>  	hash_params.hash_func_init_val = rte_rand();
> +	sad->init_val = hash_params.hash_func_init_val;
>  	hash_params.socket_id = conf->socket_id;
>  	hash_params.name = hash_name;
>  	if (conf->flags & RTE_IPSEC_SAD_FLAG_RW_CONCURRENCY)
> @@ -295,6 +301,7 @@ rte_ipsec_sad_create(const char *name, const struct rte_ipsec_sad_conf *conf)
>  	else
>  		hash_params.key_len +=
>  			sizeof(((struct rte_ipsec_sadv4_key *)0)->dip);
> +	sad->spi_dip_keysize = hash_params.key_len;
>  	hash_params.entries = RTE_MAX(MIN_HASH_ENTRIES,
>  			conf->max_sa[RTE_IPSEC_SAD_SPI_DIP]);
>  	sad->hash[RTE_IPSEC_SAD_SPI_DIP] = rte_hash_create(&hash_params);
> @@ -311,6 +318,7 @@ rte_ipsec_sad_create(const char *name, const struct rte_ipsec_sad_conf *conf)
>  	else
>  		hash_params.key_len +=
>  			sizeof(((struct rte_ipsec_sadv4_key *)0)->sip);
> +	sad->spi_dip_sip_keysize = hash_params.key_len;
>  	hash_params.entries = RTE_MAX(MIN_HASH_ENTRIES,
>  			conf->max_sa[RTE_IPSEC_SAD_SPI_DIP_SIP]);
>  	sad->hash[RTE_IPSEC_SAD_SPI_DIP_SIP] = rte_hash_create(&hash_params);
> @@ -440,15 +448,21 @@ __ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
>  	uint32_t n_3 = 0;
>  	uint32_t i;
>  	int found = 0;
> +	hash_sig_t hash_sig[RTE_HASH_LOOKUP_BULK_MAX];
> +	hash_sig_t hash_sig_2[RTE_HASH_LOOKUP_BULK_MAX];
> +	hash_sig_t hash_sig_3[RTE_HASH_LOOKUP_BULK_MAX];
> 
> -	for (i = 0; i < n; i++)
> +	for (i = 0; i < n; i++) {
>  		sa[i] = NULL;
> +		hash_sig[i] = rte_hash_crc_4byte(keys[i]->v4.spi,
> +			sad->init_val);
> +	}
> 
>  	/*
>  	 * Lookup keys in SPI only hash table first.
>  	 */
> -	rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
> -		(const void **)keys, n, &mask_1, sa);
> +	rte_hash_lookup_with_hash_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_ONLY],
> +		(const void **)keys, hash_sig, n, &mask_1, sa);
>  	for (map = mask_1; map; map &= (map - 1)) {
>  		i = rte_bsf64(map);
>  		/*
> @@ -457,10 +471,14 @@ __ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
>  		 */
>  		if ((uintptr_t)sa[i] & RTE_IPSEC_SAD_SPI_DIP_SIP) {
>  			idx_3[n_3] = i;
> +			hash_sig_3[n_3] = rte_hash_crc(keys[i],
> +				sad->spi_dip_sip_keysize, sad->init_val);
>  			keys_3[n_3++] = keys[i];
>  		}
>  		if ((uintptr_t)sa[i] & RTE_IPSEC_SAD_SPI_DIP) {
>  			idx_2[n_2] = i;
> +			hash_sig_2[n_2] = rte_hash_crc(keys[i],
> +				sad->spi_dip_keysize, sad->init_val);
>  			keys_2[n_2++] = keys[i];
>  		}
>  		/* clear 2 LSB's which indicate the presence
> @@ -471,8 +489,9 @@ __ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
> 
>  	/* Lookup for more specific rules in SPI_DIP table */
>  	if (n_2 != 0) {
> -		rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_DIP],
> -			keys_2, n_2, &mask_2, vals_2);
> +		rte_hash_lookup_with_hash_bulk_data(
> +			sad->hash[RTE_IPSEC_SAD_SPI_DIP],
> +			keys_2, hash_sig_2, n_2, &mask_2, vals_2);
>  		for (map_spec = mask_2; map_spec; map_spec &= (map_spec - 1)) {
>  			i = rte_bsf64(map_spec);
>  			sa[idx_2[i]] = vals_2[i];
> @@ -480,8 +499,9 @@ __ipsec_sad_lookup(const struct rte_ipsec_sad *sad,
>  	}
>  	/* Lookup for more specific rules in SPI_DIP_SIP table */
>  	if (n_3 != 0) {
> -		rte_hash_lookup_bulk_data(sad->hash[RTE_IPSEC_SAD_SPI_DIP_SIP],
> -			keys_3, n_3, &mask_3, vals_3);
> +		rte_hash_lookup_with_hash_bulk_data(
> +			sad->hash[RTE_IPSEC_SAD_SPI_DIP_SIP],
> +			keys_3, hash_sig_3, n_3, &mask_3, vals_3);
>  		for (map_spec = mask_3; map_spec; map_spec &= (map_spec - 1)) {
>  			i = rte_bsf64(map_spec);
>  			sa[idx_3[i]] = vals_3[i];
> --
> 2.7.4