>From: Aaron Conole [mailto:acon...@redhat.com] >Sent: Friday, June 9, 2017 8:26 PM >To: Kavanagh, Mark B <mark.b.kavan...@intel.com> >Cc: ovs-dev@openvswitch.org; Varghese, Vipin <vipin.vargh...@intel.com> >Subject: Re: [ovs-dev] [PATCH] netdev-dpdk: use rte_eth_dev_set_mtu > >Hi Mark, > >Mark Kavanagh <mark.b.kavan...@intel.com> writes: > >> DPDK provides an API to set the MTU of compatible physical devices - >> rte_eth_dev_set_mtu(). Prior to DPDK v16.07 however, this API was not >> implemented in some DPDK PMDs (i40e, specifically). To allow the use >> of jumbo frames with affected NICs in OvS-DPDK, MTU configuration was >> achieved by setting the jumbo frame flag, and corresponding maximum >> permitted Rx frame size, in an rte_eth_conf structure for the NIC >> port, and subsequently invoking rte_eth_dev_configure() with that >> configuration. >> >> However, that method does not set the MTU field of the underlying DPDK >> structure (rte_eth_dev) for the corresponding physical device; >> consequently, rte_eth_dev_get_mtu() reports the incorrect MTU for an >> OvS-DPDK phy device with non-standard MTU. >> >> Resolve this issue by invoking rte_eth_dev_set_mtu() when setting up >> or modifying the MTU of a DPDK phy port. >> >> Fixes: 0072e93 ("netdev-dpdk: add support for jumbo frames") >> Reported-by: Vipin Varghese <vipin.vargh...@intel.com> >> Signed-off-by: Mark Kavanagh <mark.b.kavan...@intel.com> >> --- > >I think I should also get a reported-by tag for this ;) :
Hey Aaron, You definitely have a much better memory than me ;) I pushed this patch in response to a request from Vipin, who flagged an issue he encountered with rte_eth_dev_get_mtu() last week. You're completely right though, you did point it out way back in January of last year - apologies for the oversight, I'll add a reported-by tag for you in v2. > >https://mail.openvswitch.org/pipermail/ovs-dev/2016-January/308828.html > >I should have probably not claimed that it wasn't a show-stopper. I >also don't see the comment I requested you to add that would warn us to >revisit this in the future :( I did add that comment in V3 of the patch, but removed it again in V4: https://mail.openvswitch.org/pipermail/ovs-dev/2016-February/309599.html. In V4, the implementation of dpdk_buf_size changed completely: == V3 == static uint32_t dpdk_buf_size(struct netdev_dpdk *netdev, int frame_len) { struct rte_eth_dev_info info; uint32_t buf_size; /* XXX: This is a workaround for DPDK v2.2, and needs to be refactored with a * future DPDK release. */ uint32_t len = frame_len + (2 * DPDK_VLAN_TAG_LEN); if(netdev->type == DPDK_DEV_ETH) { rte_eth_dev_info_get(netdev->port_id, &info); buf_size = (info.min_rx_bufsize == 0) ? NETDEV_DPDK_DEFAULT_RX_BUFSIZE : info.min_rx_bufsize; } else { buf_size = NETDEV_DPDK_DEFAULT_RX_BUFSIZE; } if(len % buf_size) { len = buf_size * ((len/buf_size) + 1); } return len; } == V4 == static uint32_t dpdk_buf_size(int mtu) { return ROUND_UP((MTU_TO_MAX_FRAME_LEN(mtu) + RTE_PKTMBUF_HEADROOM), NETDEV_DPDK_MBUF_ALIGN); } In replacing the function body, I omitted to include the comment, which is on me - sorry about that... :( Thanks, Mark > >I will carve out some time to apply and test this. Thanks Mark. > >-Aaron _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
