On Tue, Oct 5, 2021 at 9:48 PM Alexander Kozyrev <akozy...@nvidia.com> wrote:
>
> The flow rules creation/destruction at a large scale incurs a performance
> penalty and may negatively impact the packet processing when used
> as part of the datapath logic. This is mainly because software/hardware
> resources are allocated and prepared during the flow rule creation.
>
> In order to optimize the insertion rate, PMD may use some hints provided
> by the application at the initialization phase. The rte_flow_configure()
> function allows to pre-allocate all the needed resources beforehand.
> These resources can be used at a later stage without costly allocations.
> Every PMD may use only the subset of hints and ignore unused ones.
This could get tricky. An application can avoid attempts to create
flows for items/actions if it can get a hint that PMD cannot satisfy
some of the hints provided.
Also what if the application tries to configure a higher count than
what the PMD/HW can support?
It will be good if the hints can be negotiated.
Something like this?
Application could start with a set of hints.
PMD can check what can be supported and return an updated set.
Application stays within those values till it needs to resize.
>
> Signed-off-by: Alexander Kozyrev <akozy...@nvidia.com>
> Suggested-by: Ori Kam <or...@nvidia.com>
> ---
> lib/ethdev/rte_flow.h | 70 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 70 insertions(+)
>
> diff --git a/lib/ethdev/rte_flow.h b/lib/ethdev/rte_flow.h
> index 7b1ed7f110..c69d503b90 100644
> --- a/lib/ethdev/rte_flow.h
> +++ b/lib/ethdev/rte_flow.h
> @@ -4288,6 +4288,76 @@ rte_flow_tunnel_item_release(uint16_t port_id,
> struct rte_flow_item *items,
> uint32_t num_of_items,
> struct rte_flow_error *error);
> +
> +/**
> + * Flow engine configuration.
> + */
> +__extension__
> +struct rte_flow_port_attr {
> + /**
> + * Version of the struct layout, should be 0.
> + */
> + uint32_t version;
> + /**
> + * Memory size allocated for the flow rules management.
> + * If set to 0, memory is allocated dynamically.
> + */
> + uint32_t mem_size;
> + /**
> + * Number of counter actions pre-configured.
> + * If set to 0, PMD will allocate counters dynamically.
> + * @see RTE_FLOW_ACTION_TYPE_COUNT
> + */
> + uint32_t nb_counters;
> + /**
> + * Number of aging actions pre-configured.
> + * If set to 0, PMD will allocate aging dynamically.
> + * @see RTE_FLOW_ACTION_TYPE_AGE
> + */
> + uint32_t nb_aging;
> + /**
> + * Number of traffic metering actions pre-configured.
> + * If set to 0, PMD will allocate meters dynamically.
> + * @see RTE_FLOW_ACTION_TYPE_METER
> + */
> + uint32_t nb_meters;
> + /**
> + * Resources reallocation strategy.
> + * If set to 1, PMD is not allowed to allocate more resources on
> demand.
> + * An application can only allocate more resources by calling the
> + * configure API again with new values (may not be supported by PMD).
> + */
> + uint32_t fixed_resource_size:1;
> +};
> +
> +/**
> + * @warning
> + * @b EXPERIMENTAL: this API may change without prior notice.
> + *
> + * Configure flow rules module.
> + * To pre-allocate resources as per the flow port attributes,
> + * this configuration function must be called before any flow rule is
> created.
> + * No other rte_flow function should be called while this function is
> invoked.
> + * This function can be called again to change the configuration.
> + * Some PMDs may not support re-configuration at all,
> + * or may only allow increasing the number of resources allocated.
> + *
> + * @param port_id
> + * Port identifier of Ethernet device.
> + * @param[in] port_attr
> + * Port configuration attributes.
> + * @param[out] error
> + * Perform verbose error reporting if not NULL.
> + * PMDs initialize this structure in case of error only.
> + *
> + * @return
> + * 0 on success, a negative errno value otherwise and rte_errno is set.
> + */
> +__rte_experimental
> +int
> +rte_flow_configure(uint16_t port_id,
> + const struct rte_flow_port_attr *port_attr,
> + struct rte_flow_error *error);
> #ifdef __cplusplus
> }
> #endif
> --
> 2.18.2
>
