04/09/2023 09:10, Jie Hai:
> On 2023/8/30 19:46, Thomas Monjalon wrote:
> > 26/08/2023 09:46, Jie Hai:
>> + * The *func* field of the *rss_conf* structure indicates the hash
>> algorithm
> >> + * applied by the RSS hashing. Passing RTE_ETH_HASH_FUNCTION_DEFAULT
> >> allows
> >> + * the PMD to use its best-effort algorithm rather than a specific one.
> >> */
> >
> > I don't like commenting a field on top of the structure.
> > By the way, the first sentence does not look helpful.
> > RTE_ETH_HASH_FUNCTION_DEFAULT may be explained in the enum.
> >
> Other fields above the structure 'rte_eth_rss_conf' have comments.
> If the new fields 'func' do not have comments, it may be misleading.
> Unless all the comments above are removed. I'm not sure whether to
> delete them or not.
You should explain RTE_ETH_HASH_FUNCTION_DEFAULT in its enum.
The rest of the explanation can be on the struct field.
I'm OK to have another patch moving old explanations from the struct
to the fields.
> >> struct rte_eth_rss_conf {
> >> uint8_t *rss_key; /**< If not NULL, 40-byte hash key. */
> >> uint8_t rss_key_len; /**< hash key length in bytes. */
> >> uint64_t rss_hf; /**< Hash functions to apply - see below. */
> >> + enum rte_eth_hash_function func; /**< Hash algorithm to apply. */
> >
> > You can drop "to apply" words.
> Fixed in V3.
> >
> > How the algorithms support combinations in rss_hf?
> >
> The rss_hf defines the input of the RSS hash algorithms.
> For example, rss_hf = RTE_ETH_RSS_NONFRAG_IPV4_TCP | RTE_ETH_RSS_IPV4,
> these two kinds of packets can be dispatched to different queues
> according to their tuple field value.
> For ipv4-tcp packets, src-ip, dst-ip, src-port, dst-port are used as
> parameters of RSS hash algorithms to compute hash value.
> For ipv4 packets src-ip, dst-ip are used.
>
> If rss_hf = RTE_ETH_RSS_NONFRAG_IPV4_TCP | RTE_ETH_RSS_L4_SRC_ONLY, for
> ipv4-tcp packets, src-port is used as parameters of RSS hash algorithms
> to compute hash value.
I know what is rss_hf.
My question is about the algorithms.
Do they all support any combination in rss_hf?
