From: Bruce Richardson <bruce.richardson@intel.com>
To: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v3 1/4] hash: reorder hash structure
Date: Wed, 28 Sep 2016 10:02:40 +0100 [thread overview]
Message-ID: <20160928090240.GA47356@bricha3-MOBL3> (raw)
In-Reply-To: <1473190444-120795-2-git-send-email-pablo.de.lara.guarch@intel.com>
On Tue, Sep 06, 2016 at 08:34:01PM +0100, Pablo de Lara wrote:
> In order to optimize lookup performance, hash structure
> is reordered, so all fields used for lookup will be
> in the first cache line.
>
> Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
> ---
> lib/librte_hash/rte_cuckoo_hash.h | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/lib/librte_hash/rte_cuckoo_hash.h b/lib/librte_hash/rte_cuckoo_hash.h
> index e290dab..701531a 100644
> --- a/lib/librte_hash/rte_cuckoo_hash.h
> +++ b/lib/librte_hash/rte_cuckoo_hash.h
> @@ -182,9 +182,7 @@ struct rte_hash_bucket {
>
> /** A hash table structure. */
> struct rte_hash {
> - char name[RTE_HASH_NAMESIZE]; /**< Name of the hash. */
> - uint32_t entries; /**< Total table entries. */
> - uint32_t num_buckets; /**< Number of buckets in table. */
> + /* first cache line - fields used in lookup */
> uint32_t key_len; /**< Length of hash key. */
> rte_hash_function hash_func; /**< Function used to calculate hash. */
> uint32_t hash_func_init_val; /**< Init value used by hash_func. */
> @@ -196,12 +194,13 @@ struct rte_hash {
> from hash signature. */
> uint32_t key_entry_size; /**< Size of each key entry. */
>
> - struct rte_ring *free_slots; /**< Ring that stores all indexes
> - of the free slots in the key table */
> void *key_store; /**< Table storing all keys and data */
> struct rte_hash_bucket *buckets; /**< Table with buckets storing all the
> hash values and key indexes
> to the key table*/
> +
> + struct rte_ring *free_slots; /**< Ring that stores all indexes
> + of the free slots in the key table */
> uint8_t hw_trans_mem_support; /**< Hardware transactional
> memory support */
> struct lcore_cache *local_free_slots;
> @@ -209,6 +208,9 @@ struct rte_hash {
> enum add_key_case add_key; /**< Multi-writer hash add behavior */
>
> rte_spinlock_t *multiwriter_lock; /**< Multi-writer spinlock for w/o TM */
> + char name[RTE_HASH_NAMESIZE]; /**< Name of the hash. */
> + uint32_t entries; /**< Total table entries. */
> + uint32_t num_buckets; /**< Number of buckets in table. */
Hi Pablo,
While I've no strong objection to the change, having the name at the start
is a common paradigm in DPDK. Rather than place these fields at the end,
can you get the same effect by just marking the key_len function
__rte_cache_aligned? It may use a little more memory per table, but given that
the size of the hash table is going to be largely governed by the table data,
I don't see an extra 64 bytes in the structure as being an issue.
Regards,
/Bruce
next prev parent reply other threads:[~2016-09-28 9:02 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-26 21:34 [dpdk-dev] [PATCH 0/3] Cuckoo hash lookup enhancements Pablo de Lara
2016-08-26 21:34 ` [dpdk-dev] [PATCH 1/3] hash: reorganize bucket structure Pablo de Lara
2016-08-26 21:34 ` [dpdk-dev] [PATCH 2/3] hash: add vectorized comparison Pablo de Lara
2016-08-27 8:57 ` Thomas Monjalon
2016-09-02 17:05 ` De Lara Guarch, Pablo
2016-08-26 21:34 ` [dpdk-dev] [PATCH 3/3] hash: modify lookup bulk pipeline Pablo de Lara
2016-09-02 22:56 ` [dpdk-dev] [PATCH v2 0/4] Cuckoo hash lookup enhancements Pablo de Lara
2016-09-02 22:56 ` [dpdk-dev] [PATCH v2 1/4] hash: reorder hash structure Pablo de Lara
2016-09-02 22:56 ` [dpdk-dev] [PATCH v2 2/4] hash: reorganize bucket structure Pablo de Lara
2016-09-02 22:56 ` [dpdk-dev] [PATCH v2 3/4] hash: add vectorized comparison Pablo de Lara
2016-09-02 22:56 ` [dpdk-dev] [PATCH v2 4/4] hash: modify lookup bulk pipeline Pablo de Lara
2016-09-06 19:33 ` [dpdk-dev] [PATCH v3 0/4] Cuckoo hash lookup enhancements Pablo de Lara
2016-09-30 7:38 ` [dpdk-dev] [PATCH v4 0/4] Cuckoo hash enhancements Pablo de Lara
2016-09-30 7:38 ` [dpdk-dev] [PATCH v4 1/4] hash: reorder hash structure Pablo de Lara
2016-09-30 7:38 ` [dpdk-dev] [PATCH v4 2/4] hash: reorganize bucket structure Pablo de Lara
2016-09-30 7:38 ` [dpdk-dev] [PATCH v4 3/4] hash: add vectorized comparison Pablo de Lara
2016-09-30 7:38 ` [dpdk-dev] [PATCH v4 4/4] hash: modify lookup bulk pipeline Pablo de Lara
2016-09-30 19:53 ` [dpdk-dev] [PATCH v4 0/4] Cuckoo hash enhancements Gobriel, Sameh
2016-10-03 9:59 ` Bruce Richardson
2016-10-04 6:50 ` De Lara Guarch, Pablo
2016-10-04 7:17 ` De Lara Guarch, Pablo
2016-10-04 9:47 ` Bruce Richardson
2016-10-04 23:25 ` [dpdk-dev] [PATCH v5 " Pablo de Lara
2016-10-04 23:25 ` [dpdk-dev] [PATCH v5 1/4] hash: reorder hash structure Pablo de Lara
2016-10-04 23:25 ` [dpdk-dev] [PATCH v5 2/4] hash: reorganize bucket structure Pablo de Lara
2016-10-04 23:25 ` [dpdk-dev] [PATCH v5 3/4] hash: add vectorized comparison Pablo de Lara
2016-10-04 23:25 ` [dpdk-dev] [PATCH v5 4/4] hash: modify lookup bulk pipeline Pablo de Lara
2016-10-05 10:12 ` [dpdk-dev] [PATCH v5 0/4] Cuckoo hash enhancements Thomas Monjalon
2016-09-06 19:34 ` [dpdk-dev] [PATCH v3 0/4] Cuckoo hash lookup enhancements Pablo de Lara
2016-09-06 19:34 ` [dpdk-dev] [PATCH v3 1/4] hash: reorder hash structure Pablo de Lara
2016-09-28 9:02 ` Bruce Richardson [this message]
2016-09-29 1:33 ` De Lara Guarch, Pablo
2016-09-06 19:34 ` [dpdk-dev] [PATCH v3 2/4] hash: reorganize bucket structure Pablo de Lara
2016-09-28 9:05 ` Bruce Richardson
2016-09-29 1:40 ` De Lara Guarch, Pablo
2016-09-06 19:34 ` [dpdk-dev] [PATCH v3 3/4] hash: add vectorized comparison Pablo de Lara
2016-09-06 19:34 ` [dpdk-dev] [PATCH v3 4/4] hash: modify lookup bulk pipeline Pablo de Lara
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