Re: [PATCH] lib/hash,lib/rcu: feature hidden key count in hash

[Thomas Monjalon <thomas@monjalon.net>]

Any review please?


07/02/2024 16:33, Abdullah Ömer Yamaç:
> This patch introduce a new API to get the hidden key count in the hash
> table if the rcu qsbr is enabled. When using rte_hash_count with rcu
> qsbr enabled, it will return the number of elements that are not in the
> free queue. Unless rte_rcu_qsbr_dq_reclaim is called, the number of
> elements in the defer queue will not be counted and freed. Therefore I
> added a new API to get the number of hidden (defer queue) elements
> in the hash table. Then the user can calculate the total number of
> elements that are available in the hash table.
> 
> Signed-off-by: Abdullah Ömer Yamaç <aomeryamac@gmail.com>
> 
> ---
> Cc: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Cc: Yipeng Wang <yipeng1.wang@intel.com>
> Cc: Sameh Gobriel <sameh.gobriel@intel.com>
> Cc: Bruce Richardson <bruce.richardson@intel.com>
> Cc: Vladimir Medvedkin <vladimir.medvedkin@intel.com>
> ---
>  lib/hash/rte_cuckoo_hash.c |  9 +++++++++
>  lib/hash/rte_hash.h        | 13 +++++++++++++
>  lib/hash/version.map       |  1 +
>  lib/rcu/rte_rcu_qsbr.c     |  8 ++++++++
>  lib/rcu/rte_rcu_qsbr.h     | 11 +++++++++++
>  lib/rcu/version.map        |  1 +
>  6 files changed, 43 insertions(+)
> 
> diff --git a/lib/hash/rte_cuckoo_hash.c b/lib/hash/rte_cuckoo_hash.c
> index 70456754c4..3553f3efc7 100644
> --- a/lib/hash/rte_cuckoo_hash.c
> +++ b/lib/hash/rte_cuckoo_hash.c
> @@ -555,6 +555,15 @@ rte_hash_max_key_id(const struct rte_hash *h)
>  		return h->entries;
>  }
>  
> +int32_t
> +rte_hash_dq_count(const struct rte_hash *h)
> +{
> +	if (h->dq == NULL)
> +		return -EINVAL;
> +
> +	return rte_rcu_qsbr_dq_count(h->dq);
> +}
> +
>  int32_t
>  rte_hash_count(const struct rte_hash *h)
>  {
> diff --git a/lib/hash/rte_hash.h b/lib/hash/rte_hash.h
> index 7ecc021111..8ea97e297d 100644
> --- a/lib/hash/rte_hash.h
> +++ b/lib/hash/rte_hash.h
> @@ -193,6 +193,19 @@ rte_hash_free(struct rte_hash *h);
>  void
>  rte_hash_reset(struct rte_hash *h);
>  
> +
> +/**
> + * Return the number of records in the defer queue of the hash table 
> + * if RCU is enabled.
> + * @param h
> + *  Hash table to query from
> + * @return
> + *   - -EINVAL if parameters are invalid
> + *   - A value indicating how many records were inserted in the table.
> + */
> +int32_t
> +rte_hash_dq_count(const struct rte_hash *h);
> +
>  /**
>   * Return the number of keys in the hash table
>   * @param h
> diff --git a/lib/hash/version.map b/lib/hash/version.map
> index 6b2afebf6b..7f7b158cf1 100644
> --- a/lib/hash/version.map
> +++ b/lib/hash/version.map
> @@ -9,6 +9,7 @@ DPDK_24 {
>  	rte_hash_add_key_with_hash;
>  	rte_hash_add_key_with_hash_data;
>  	rte_hash_count;
> +	rte_hash_dq_count;
>  	rte_hash_crc32_alg;
>  	rte_hash_crc_set_alg;
>  	rte_hash_create;
> diff --git a/lib/rcu/rte_rcu_qsbr.c b/lib/rcu/rte_rcu_qsbr.c
> index bd0b83be0c..89f8da4c4c 100644
> --- a/lib/rcu/rte_rcu_qsbr.c
> +++ b/lib/rcu/rte_rcu_qsbr.c
> @@ -450,6 +450,14 @@ rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq *dq, unsigned int n,
>  	return 0;
>  }
>  
> +/**
> + * Return the number of entries in a defer queue.
> + */
> +unsigned int rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr_dq *dq)
> +{
> +	return rte_ring_count(dq->r);
> +}
> +
>  /* Delete a defer queue. */
>  int
>  rte_rcu_qsbr_dq_delete(struct rte_rcu_qsbr_dq *dq)
> diff --git a/lib/rcu/rte_rcu_qsbr.h b/lib/rcu/rte_rcu_qsbr.h
> index 23c9f89805..ed5a590edd 100644
> --- a/lib/rcu/rte_rcu_qsbr.h
> +++ b/lib/rcu/rte_rcu_qsbr.h
> @@ -794,6 +794,17 @@ int
>  rte_rcu_qsbr_dq_reclaim(struct rte_rcu_qsbr_dq *dq, unsigned int n,
>  	unsigned int *freed, unsigned int *pending, unsigned int *available);
>  
> +/**
> + * Return the number of entries in a defer queue.
> + *
> + * @param dq
> + *   Defer queue.
> + * @return
> + *   The number of entries in the defer queue.
> + */
> +unsigned int
> +rte_rcu_qsbr_dq_count(struct rte_rcu_qsbr_dq *dq);
> +
>  /**
>   * Delete a defer queue.
>   *
> diff --git a/lib/rcu/version.map b/lib/rcu/version.map
> index 982ffd59d9..f410ab41e7 100644
> --- a/lib/rcu/version.map
> +++ b/lib/rcu/version.map
> @@ -5,6 +5,7 @@ DPDK_24 {
>  	rte_rcu_qsbr_dq_create;
>  	rte_rcu_qsbr_dq_delete;
>  	rte_rcu_qsbr_dq_enqueue;
> +	rte_rcu_qsbr_dq_count;
>  	rte_rcu_qsbr_dq_reclaim;
>  	rte_rcu_qsbr_dump;
>  	rte_rcu_qsbr_get_memsize;
>