On Mon, Mar 16, 2020 at 6:22 PM BillZhou <do...@mellanox.com> wrote:
>
> One of the reasons to destroy a flow is the fact that no packet matches the
> flow for "timeout" time.
> For example, when TCP\UDP sessions are suddenly closed.
>
> Currently, there is no any dpdk mechanism for flow aging and the
> applications use there own ways to detect and destroy aged-out flows.
>
> This RFC introduces flow aging APIs to offload the flow aging task from
> the application to the port.
>
> Design:
> - A new rte_flow action: RTE_FLOW_ACTION_TYPE_AGE to set the timeout and
> the application flow context for each flow.
> - A new ethdev event: RTE_ETH_EVENT_FLOW_AGED for the driver to report
> that there are new aged-out flows.
> - A new rte_flow API: rte_flow_get_aged_flows to get the aged-out flows
> contexts from the port.
>
> By this design each PMD can use its best way to do the aging with the
> device offloads supported by its HW.
>
> Signed-off-by: BillZhou <do...@mellanox.com>
> ---
> v2:For API rte_flow_get_aged_flows, delete "struct rte_flow *flows[]"
> this parameter.
> ---
> lib/librte_ethdev/rte_ethdev.h | 1 +
> lib/librte_ethdev/rte_flow.h | 56 ++++++++++++++++++++++++++++++++++
> 2 files changed, 57 insertions(+)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index d1a593ad11..03135a7138 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -3015,6 +3015,7 @@ enum rte_eth_event_type {
> RTE_ETH_EVENT_NEW, /**< port is probed */
> RTE_ETH_EVENT_DESTROY, /**< port is released */
> RTE_ETH_EVENT_IPSEC, /**< IPsec offload related event */
> + RTE_ETH_EVENT_FLOW_AGED,/**< New aged-out flows detected in the port
> */
> RTE_ETH_EVENT_MAX /**< max value of this enum */
> };
>
> diff --git a/lib/librte_ethdev/rte_flow.h b/lib/librte_ethdev/rte_flow.h
> index 5625dc4917..1fc05bf56c 100644
> --- a/lib/librte_ethdev/rte_flow.h
> +++ b/lib/librte_ethdev/rte_flow.h
> @@ -2051,6 +2051,14 @@ enum rte_flow_action_type {
> * See struct rte_flow_action_set_dscp.
> */
> RTE_FLOW_ACTION_TYPE_SET_IPV6_DSCP,
> +
> + /**
> + * Report as aged-out if timeout passed without any matching on the
> + * flow.
> + *
> + * See struct rte_flow_action_age.
> + */
> + RTE_FLOW_ACTION_TYPE_AGE,
> };
>
> /**
> @@ -2633,6 +2641,22 @@ struct rte_flow_action {
> const void *conf; /**< Pointer to action configuration object. */
> };
>
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this structure may change without prior notice
> + *
> + * RTE_FLOW_ACTION_TYPE_AGE
> + *
> + * Report as aged-out if timeout passed without any matching on the flow.
> + *
> + * The flow context and the flow handle will be reported by the
> + * rte_flow_get_aged_flows API.
> + */
> +struct rte_flow_action_age {
> + uint16_t timeout; /**< Time in seconds. */
> + void *context; /**< The user flow context. */
> +};
> +
> /**
> * Opaque type returned after successfully creating a flow.
> *
> @@ -3224,6 +3248,38 @@ rte_flow_conv(enum rte_flow_conv_op op,
> const void *src,
> struct rte_flow_error *error);
>
> +/**
> + * Get aged-out flows of a given port.
> + *
> + * RTE_ETH_EVENT_FLOW_AGED is triggered when a port detects aged-out flows.
> + * This function can be called to get the aged flows usynchronously from the
s/usynchronously/ asynchronously
> + * event callback or synchronously when the user wants it.
> + * The callback synchronization is on the user responsibility.
> + *
> + * @param port_id
> + * Port identifier of Ethernet device.
> + * @param[in/out] contexts
> + * An allocated array to get the aged-out flows contexts from input age
> + * action config, if input contexts is null, return the aged-out flows.
> + * NULL indicates the flow contexts should not be reported.
> + * @param[in] nb_context
By default, everything is [in]. Not need to mention [in] explicitly.
> + * The allocated array entries number of @p contexts if exist.
> + * @param[out] error
> + * Perform verbose error reporting if not NULL. Initialized in case of
> + * error only.
> + *
> + * @return
> + * 0 in case there are not any aged-out contexts or flows, otherwise if
> + * positive is the number of the reported aged-out contexts or flows to
> + * @p contexts, a negative errno value otherwise and rte_errno is set.
> + *
> + * @see rte_flow_action_age
RTE_ETH_EVENT_FLOW_AGED can be added in @see
Other than the above nits,
This RFC looks good to me.
> + */
> +__rte_experimental
> +int
> +rte_flow_get_aged_flows(uint16_t port_id, void *contexts[],
> + int nb_context, struct rte_flow_error *error);
> +
> #ifdef __cplusplus
> }
> #endif
> --
> 2.21.0
>
