On 11/30/2015 07:53 PM, Richardson, Bruce wrote: > > >> -----Original Message----- >> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Alexey Bogdanenko >> Sent: Monday, November 30, 2015 4:17 PM >> To: dev at dpdk.org >> Subject: [dpdk-dev] Unable to configure ethdev in secondary process using >> ring PMD >> >> Hello, >> >> I would like to setup communication between two existing DPDK applications >> and run them on the same host. >> >> "Connecting their ports" in some way in order not to rewrite the >> applications would be very desirable. Specifically, I would like one >> process to send packets and the second process to receive the packets >> using rte_eth_tx_burst() and rte_eth_rx_burst() respectively. >> >> The most straightforward way to accomplish this seems to be by using ring >> based PMD API as described in the documentation [1] and email [2]. >> To adapt the example from the documentation to multi-process scenario, I >> call rte_ring_create() and rte_eth_from_rings() in the primary process, >> rte_ring_lookup() and rte_eth_from_rings() in the secondary process. >> After that each process calls rte_eth_dev_configure(). >> >> Unfortunately, the function returns -1001 in the secondary process, which >> is explained in debug log: >> >> PMD: rte_eth_dev_configure: Cannot run in secondary processes >> >> Is it possible to connect the applications as described above? Any advice >> would be appreciated. >> >> References: >> >> 1. Network Interface Controller Drivers. Chapter 8. >> Libpcap and Ring Based Poll Mode Drivers. >> >> 2. DPDK ML. Fri Dec 6 07:22:06 CET 2013. How to know corresponding device >> from port number. Tetsuya.Mukawa >> >> Thanks, >> >> Alexey Bogdanenko > > Hi Alexey, > > The ring PMDs returned from eth_from_rings should be all ready to be used > without having to explicitly configure it or set up the queues. > > /Bruce >
Thanks for the quick reply, I updated dpdk from v2.1.0 to a more recent version (near v2.2.0-rc2), removed calls to rte_eth_dev_configure(), rte_eth_rx_queue_setup(). It solved the problem. Your advice was very helpful. However, I encountered a rather minor but similar issue, which is that rte_eth_dev_start() returns -1001 in the secondary processes. The message I get is: rte_eth_dev_start: Cannot run in secondary processes Now, I could avoid calling the function altogether, however in this case rte_eth_link_get_nowait() reports that the link status is down which is a bit inconvenient. Did I miss anything or is it just a limitation of ring PMD? Alexey Bogdanenko
