[dpdk-users] Proper way of notifying the application that DPDK received messages

[dpdk-users] Proper way of notifying the application that DPDK received messages

[Sungho Hong]

Hello

currently, I'am using dpdk by sending and receiving the packets in to the
rte-rings. I'am having difficulty of finding the proper way of to notify
the application that the DPDK received incoming messages.

In order to check the whether the rte_ring has received the data or not, I
run a busy loop on the rte_ring.
here is the example below

while (1) {
  if (rte_ring_dequeue(rx_ring, &_msg) < 0) {
    usleep(5);
  } else {
    recv_msg = (char *) _msg;
    if (chara_debug) printf("[%d] Server merge
data::[%.24s...]__length::[%ld]\n", batched_packets, recv_msg,
strlen(recv_msg));
    collect_packets++;
    if (collect_packets > MERGE_PACKETS) break;
  }
}

However, my fellow developers say that this is not a efficient way nor the
proper way of checking received messages. Busy polling should be only done
in the DPDK API and not in the application.

Is there a way for DPDK to send a signal to the application so that the
application can only check the rte_ring only when there is a received
message?.

Re: [dpdk-users] Proper way of notifying the application that DPDK received messages

[Stephen Hemminger]

On Wed, 29 Aug 2018 16:56:51 -0700
Sungho Hong <maverickjin88@gmail.com> wrote:

> Hello
> 
> currently, I'am using dpdk by sending and receiving the packets in to the
> rte-rings. I'am having difficulty of finding the proper way of to notify
> the application that the DPDK received incoming messages.
> 
> In order to check the whether the rte_ring has received the data or not, I
> run a busy loop on the rte_ring.
> here is the example below
> 
> while (1) {
>   if (rte_ring_dequeue(rx_ring, &_msg) < 0) {
>     usleep(5);
>   } else {
>     recv_msg = (char *) _msg;
>     if (chara_debug) printf("[%d] Server merge
> data::[%.24s...]__length::[%ld]\n", batched_packets, recv_msg,
> strlen(recv_msg));
>     collect_packets++;
>     if (collect_packets > MERGE_PACKETS) break;
>   }
> }
> 
> However, my fellow developers say that this is not a efficient way nor the
> proper way of checking received messages. Busy polling should be only done
> in the DPDK API and not in the application.
> 
> Is there a way for DPDK to send a signal to the application so that the
> application can only check the rte_ring only when there is a received
> message?.

If you notification, look into the interrupt mode.

Re: [dpdk-users] Proper way of notifying the application that DPDK received messages

[Sungho Hong]

Hi Stephen thanks for the reply,

but, what I am asking is using while loop on the rx-queue the proper way
for applications to use DPDK for sending and receiving data? Or is there
any notification mechanism that works even in polling-mode?