[PATCH v2 3/3] examples/l3fwd: enable direct rearm mode

[Jerin Jacob]

On Tue, Sep 27, 2022 at 8:18 AM Feifei Wang <feifei.wang2 at arm.com> wrote:
>
> Enable direct rearm mode in l3fwd. Users can use parameters:
> '--direct-rearm=(rx_portid,rx_queueid,tx_portid,tx_queueid)'
> to enable direct rearm.
>
> Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> Signed-off-by: Feifei Wang <feifei.wang2 at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli at arm.com>
> ---
>  examples/l3fwd/l3fwd.h     | 12 +++++
>  examples/l3fwd/l3fwd_lpm.c | 22 +++++++++
>  examples/l3fwd/main.c      | 94 +++++++++++++++++++++++++++++++++++++-
>  3 files changed, 127 insertions(+), 1 deletion(-)
>
> diff --git a/examples/l3fwd/l3fwd.h b/examples/l3fwd/l3fwd.h
> index 40b5f32a9e..db097e344c 100644
> --- a/examples/l3fwd/l3fwd.h
> +++ b/examples/l3fwd/l3fwd.h
> @@ -57,6 +57,10 @@
>  #endif
>  #define HASH_ENTRY_NUMBER_DEFAULT      16
>
> +/* MAX number of direct rearm mapping entry */
> +#define MAX_DIRECT_REARM_ENTRY_NUMBER   16
> +#define MAX_DIRECT_REARM_QUEUE_PER_PORT 8
> +
>  struct parm_cfg {
>         const char *rule_ipv4_name;
>         const char *rule_ipv6_name;
> @@ -114,6 +118,14 @@ extern struct parm_cfg parm_config;
>
>  extern struct acl_algorithms acl_alg[];
>
> +/* Used in direct rearm mode */
> +extern bool enabled_direct_rearm;
> +extern uint8_t direct_rearm_entry_number;
> +extern bool queue_enabled_direct_rearm[RTE_MAX_ETHPORTS][MAX_DIRECT_REARM_QUEUE_PER_PORT];
> +extern uint16_t direct_rearm_map_tx_port[RTE_MAX_ETHPORTS][MAX_DIRECT_REARM_QUEUE_PER_PORT];
> +extern uint16_t direct_rearm_map_tx_queue[RTE_MAX_ETHPORTS][MAX_DIRECT_REARM_QUEUE_PER_PORT];
> +extern uint8_t direct_rearm_entry_idx[RTE_MAX_ETHPORTS][MAX_DIRECT_REARM_QUEUE_PER_PORT];
> +
>  /* Send burst of packets on an output interface */
>  static inline int
>  send_burst(struct lcore_conf *qconf, uint16_t n, uint16_t port)
> diff --git a/examples/l3fwd/l3fwd_lpm.c b/examples/l3fwd/l3fwd_lpm.c
> index 22d7f61a42..973fe70aae 100644
> --- a/examples/l3fwd/l3fwd_lpm.c
> +++ b/examples/l3fwd/l3fwd_lpm.c
> @@ -150,6 +150,8 @@ lpm_main_loop(__rte_unused void *dummy)

> @@ -205,6 +221,12 @@ lpm_main_loop(__rte_unused void *dummy)
>                 for (i = 0; i < n_rx_q; ++i) {
>                         portid = qconf->rx_queue_list[i].port_id;
>                         queueid = qconf->rx_queue_list[i].queue_id;
> +
> +                       if (queue_enabled_direct_rearm[portid][queueid]) {

IMO, We should not change fastpath code that impacts performance on
other targets for a
feature which has a very constraint use case. Also need for expressing
[1], kind of defeat the purpose
LPM table populated.

IMO, If we need to add a test case for this API, testpmd would be an
ideal place with a dedicated fwd_engine just for this.

[1]
> +               "  --direct-rearm (rx_port, rx_queue, tx_port, tx_queue): Put Tx queue sw-ring buffers into Rx queue\n"