[dpdk-dev] [PATCH] app/testpmd: make txonly mode generate multiple flows

[Lu, Wenzhuo]

Hi Yongseok,

> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Yongseok Koh
> Sent: Saturday, December 16, 2017 5:11 AM
> To: Wu, Jingjing <jingjing.wu at intel.com>
> Cc: dev at dpdk.org; Yongseok Koh <yskoh at mellanox.com>
> Subject: [dpdk-dev] [PATCH] app/testpmd: make txonly mode generate
> multiple flows
> 
> Testpmd can generate multiple flows without taking much cost and this
> could be a simple traffic generator for developer's quick tests. IP destination
> address is varied.
> 
> Signed-off-by: Yongseok Koh <yskoh at mellanox.com>
> ---
>  app/test-pmd/txonly.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/app/test-pmd/txonly.c b/app/test-pmd/txonly.c index
> 309c73893..aa4c379c4 100644
> --- a/app/test-pmd/txonly.c
> +++ b/app/test-pmd/txonly.c
> @@ -73,7 +73,7 @@
>  #define UDP_DST_PORT 1024
> 
>  #define IP_SRC_ADDR ((192U << 24) | (168 << 16) | (0 << 8) | 1) -#define
> IP_DST_ADDR ((192U << 24) | (168 << 16) | (0 << 8) | 2)
> +#define IP_DST_ADDR ((192U << 24) | (168 << 16))
> 
>  #define IP_DEFTTL  64   /* from RFC 1340. */
>  #define IP_VERSION 0x40
> @@ -81,6 +81,7 @@
>  #define IP_VHL_DEF (IP_VERSION | IP_HDRLEN)
> 
>  static struct ipv4_hdr  pkt_ip_hdr;  /**< IP header of transmitted packets. */
> +static __thread uint8_t ip_var; /**< IP address variation */
>  static struct udp_hdr pkt_udp_hdr; /**< UDP header of transmitted packets.
> */
> 
>  static void
> @@ -187,6 +188,7 @@ pkt_burst_transmit(struct fwd_stream *fs)
>  	struct rte_mbuf *pkt_seg;
>  	struct rte_mempool *mbp;
>  	struct ether_hdr eth_hdr;
> +	struct ipv4_hdr *ip_hdr;
>  	uint16_t nb_tx;
>  	uint16_t nb_pkt;
>  	uint16_t vlan_tci, vlan_tci_outer;
> @@ -263,6 +265,14 @@ pkt_burst_transmit(struct fwd_stream *fs)
>  		copy_buf_to_pkt(&eth_hdr, sizeof(eth_hdr), pkt, 0);
>  		copy_buf_to_pkt(&pkt_ip_hdr, sizeof(pkt_ip_hdr), pkt,
>  				sizeof(struct ether_hdr));
> +		ip_hdr = rte_pktmbuf_mtod_offset(pkt, struct ipv4_hdr *,
> +						 sizeof(struct ether_hdr));
> +		/*
> +		 * Generate multiple flows by varying IP dest addr.
> +		 */
> +		ip_hdr->dst_addr =
> +			rte_cpu_to_be_32(IP_DST_ADDR | (ip_var++ << 8) |
> +					 (rte_lcore_id() + 1));
Just curious if we can avoid call rte_lcore_id for every packet?

And suggest to add more explanation here, like purpose, scenario. So when we want to change the behavior, for example, like adding a parameter to make IP addresses configurable, we know what we will break.

>  		copy_buf_to_pkt(&pkt_udp_hdr, sizeof(pkt_udp_hdr), pkt,
>  				sizeof(struct ether_hdr) +
>  				sizeof(struct ipv4_hdr));
> --
> 2.11.0