[PATCH v3 2/2] ring: add ring info telemetry cmd

[Konstantin Ananyev]

31/01/2023 02:28, Jie Hai пишет:
> This patch supports dump of the info of ring by its name.
> An example using this command is shown below:
> 
> --> /ring/info,MP_mb_pool_0
> {
>    "/ring/info": {
>      "name": "MP_mb_pool_0",
>      "socket": 0,
>      "flags": 0,
>      "producer_type": "MP",
>      "consumer_type": "MC",
>      "size": 262144,
>      "mask": 262143,
>      "capacity": 262143,
>      "used_count": 147173,
>      "consumer_tail": 8283,
>      "consumer_head": 8283,
>      "producer_tail": 155456,
>      "producer_head": 155456,
>      "mz_name": "RG_MP_mb_pool_0",
>      "mz_len": 2097920,
>      "mz_hugepage_sz": 1073741824,
>      "mz_socket_id": 0,
>      "mz_flags": 0
>    }
> }
> 
> Signed-off-by: Jie Hai <haijie1 at huawei.com>
> ---
>   lib/ring/rte_ring.c | 83 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 83 insertions(+)
> 
> diff --git a/lib/ring/rte_ring.c b/lib/ring/rte_ring.c
> index e6aac332d88f..2e57aa653339 100644
> --- a/lib/ring/rte_ring.c
> +++ b/lib/ring/rte_ring.c
> @@ -454,8 +454,91 @@ ring_handle_list(const char *cmd __rte_unused,
>   	return 0;
>   }
>   
> +static const char *
> +ring_prod_sync_type_to_name(struct rte_ring *r)
> +{
> +	switch (r->prod.sync_type) {
> +	case RTE_RING_SYNC_MT:
> +		return "MP";
> +	case RTE_RING_SYNC_ST:
> +		return "SP";
> +	case RTE_RING_SYNC_MT_RTS:
> +		return "MP_RTS";
> +	case RTE_RING_SYNC_MT_HTS:
> +		return "MP_HTS";
> +	default:
> +		return "Unknown";
> +	}
> +}
> +
> +static const char *
> +ring_cons_sync_type_to_name(struct rte_ring *r)
> +{
> +	switch (r->cons.sync_type) {
> +	case RTE_RING_SYNC_MT:
> +		return "MC";
> +	case RTE_RING_SYNC_ST:
> +		return "SC";
> +	case RTE_RING_SYNC_MT_RTS:
> +		return "MC_RTS";
> +	case RTE_RING_SYNC_MT_HTS:
> +		return "MC_HTS";
> +	default:
> +		return "Unknown";
> +	}
> +}
> +
> +static int
> +ring_handle_info(const char *cmd __rte_unused, const char *params,
> +		struct rte_tel_data *d)
> +{
> +	const struct rte_memzone *mz;
> +	struct rte_ring *r;
> +
> +	if (params == NULL || strlen(params) == 0 ||
> +		strlen(params) >= RTE_RING_NAMESIZE)
> +		return -EINVAL;
> +
> +	r = rte_ring_lookup(params);
> +	if (r == NULL)
> +		return -EINVAL;

thanks for the update, but I think there still a potential problem here:
as we release tailq_lock inside ring_lookup() and then grab it after again.
Between these two points we have sort of race condition.
We need a way not to release it in between.
Probably the simplest way - make this function to use ring_walk()
that you introduced in previous patch, instead of ring_lookup().
Similar to what mempool_handle_info() is doing.


> +
> +	rte_mcfg_tailq_read_lock();
> +
> +	rte_tel_data_start_dict(d);
> +	rte_tel_data_add_dict_string(d, "name", r->name);
> +	rte_tel_data_add_dict_int(d, "socket", r->memzone->socket_id);
> +	rte_tel_data_add_dict_int(d, "flags", r->flags);
> +	rte_tel_data_add_dict_string(d, "producer_type",
> +		ring_prod_sync_type_to_name(r));
> +	rte_tel_data_add_dict_string(d, "consumer_type",
> +		ring_cons_sync_type_to_name(r));
> +	rte_tel_data_add_dict_u64(d, "size", r->size);
> +	rte_tel_data_add_dict_u64(d, "mask", r->mask);
> +	rte_tel_data_add_dict_u64(d, "capacity", r->capacity);
> +	rte_tel_data_add_dict_u64(d, "used_count", rte_ring_count(r));
> +	rte_tel_data_add_dict_u64(d, "consumer_tail", r->cons.tail);
> +	rte_tel_data_add_dict_u64(d, "consumer_head", r->cons.head);
> +	rte_tel_data_add_dict_u64(d, "producer_tail", r->prod.tail);
> +	rte_tel_data_add_dict_u64(d, "producer_head", r->prod.head);
> +
> +	mz = r->memzone;
> +	if (mz == NULL)
> +		return 0;
> +	rte_tel_data_add_dict_string(d, "mz_name", mz->name);
> +	rte_tel_data_add_dict_int(d, "mz_len", mz->len);
> +	rte_tel_data_add_dict_int(d, "mz_hugepage_sz", mz->hugepage_sz);
> +	rte_tel_data_add_dict_int(d, "mz_socket_id", mz->socket_id);
> +	rte_tel_data_add_dict_int(d, "mz_flags", mz->flags);
> +
> +	rte_mcfg_tailq_read_unlock();
> +	return 0;
> +}
> +
>   RTE_INIT(ring_init_telemetry)
>   {
>   	rte_telemetry_register_cmd("/ring/list", ring_handle_list,
>   		"Returns list of available ring. Takes no parameters");
> +	rte_telemetry_register_cmd("/ring/info", ring_handle_info,
> +		"Returns ring info. Parameters: ring_name.");
>   }