[dpdk-users] X710/i40e and vector pmd rx 2.2.0 in an rx only mode

martin_curran-gray at keysight.com martin_curran-gray at keysight.com
Tue Aug 2 11:53:23 CEST 2016


Hi,

So I found my issue with vector mode not being enabled was due to a linking issue in my build environment, it was picking up the stub that returned -1 on the check of conditions, even though I had enabled vector mode in the config before I built the environment.

However now I have vector mode working, I never seem to free any mbufs, so my app works great for about a second, then of course everything coming in gets dropped.

Is there something different I have to do to get my mbufs free'd if the vector rx function is being used rather than the bulk_alloc rx function?

I can run the l2fwd function fine, and it is using vector mode, but


L2fwd output

Initializing port 0... PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are satisfied. Rx Burst Bulk Alloc function will be used on port=0, queue=0.
PMD: i40e_set_tx_function_flag(): Vector tx can be enabled on this txq.
PMD: i40e_set_tx_function(): Vector tx finally be used.
PMD: i40e_set_rx_function(): Vector rx enabled, please make sure RX burst size no less than 4 (port=0).
done:
Port 0, MAC address: 68:05:CA:27:F1:BC

My output

PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are satisfied. Rx Burst Bulk Alloc function will be used on port=0, queue=0.
PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are satisfied. Rx Burst Bulk Alloc function will be used on port=0, queue=1.
PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are satisfied. Rx Burst Bulk Alloc function will be used on port=0, queue=2.
PMD: i40e_dev_rx_queue_setup(): Rx Burst Bulk Alloc Preconditions are satisfied. Rx Burst Bulk Alloc function will be used on port=0, queue=3.
PMD: i40e_set_tx_function(): Xmit tx finally be used.
PMD: i40e_pf_config_rss(): Max of contiguous 4 PF queues are configured
PMD: i40e_set_rx_function(): Vector rx enabled, please make sure RX burst size no less than 4 (port=0).



So the code in i40e_rxtx.c seems to imply I should be either using vector or bulk

dev->rx_pkt_burst = i40e_recv_pkts_vec;
or
dev->rx_pkt_burst = i40e_recv_pkts_bulk_alloc;


I seem to be going through this function twice?  But so does l2fwd...

however

l2fwd I think has the transmit function free up the buffers after they are sent?

I use explicit calls to rte_mempool_put_bulk to free up buffers I've finished with?

I can see a report in the release notes for 16.04.0 about an issue with ixgbe and releasing mbufs, did/does the i40e suffer from similar problems?


Any suggestions gratefully received

thanks

Martin

martin _ curran - gray @ keysight . com

(remove the spaces)


Martin Curran-Gray
HW/FPGA/SW Engineer
Keysight Technologies UK Ltd


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