On 10/11/2017 02:04 PM, Fischetti, Antonio wrote: > >> -----Original Message----- >> From: Kevin Traynor [mailto:ktray...@redhat.com] >> Sent: Wednesday, October 11, 2017 11:40 AM >> To: Fischetti, Antonio <antonio.fische...@intel.com>; Róbert Mulik >> <robert.mu...@ericsson.com>; d...@openvswitch.org >> Subject: Re: [ovs-dev] [PATCH v3 1/5] netdev-dpdk: fix mempool management >> with >> vhu client. >> >> On 10/11/2017 11:28 AM, Fischetti, Antonio wrote: >>> Hi Robert, >>> that's happening because the requested MTU is rounded up to the current >> boundary. >>> So if the current upper boundary is 2500 and we request 2000 => >>> 2000 is rounded up to 2500 and the same mempool is returned. >>> >>> I may be wrong but this seems the wanted behavior, maybe Kevin can shed some >> light? >>> I may have missed some detail as I didn't follow this implementation since >> the >>> very beginning. >>> >> >> I think it's related to review comments I sent earlier today. mtu is >> mtu, but a value that is rounded from it is used in calculating the size >> of the mbuf. I suspect in this case, when the new mtu size results in >> the same rounded value, the current mempool is being reused (which is >> fine) > > [Antonio] exactly. > >> but the EEXISTS error value returned from reconfigure means that >> the change is not seen as successful and the old mtu value is restored >> to ovsdb. > > [Antonio] > I think this can be fixed by the following changes. > The new mtu value is stored when a pre-existing mempool is returned: > __________________________________________________________________________ > @@ -631,6 +631,11 @@ netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) > rte_strerror(rte_errno)); > return rte_errno; > } else if (mp_exists) { > + /* If a new MTU was requested and its rounded value is the same > + * that is currently used, then the existing mempool was returned. > + * Update the new MTU value. */ > + dev->mtu = dev->requested_mtu; > + dev->max_packet_len = MTU_TO_FRAME_LEN(dev->mtu);
What about requested_socket_id, isn't that needed also? > return EEXIST; > } else { > dpdk_mp_put(dev->dpdk_mp); > __________________________________________________________________________ > > Instead, inside netdev_dpdk_reconfigure() I think it should be correct to have > > err = netdev_dpdk_mempool_configure(dev); > if (err && err != EEXIST) { > goto out; > } > > because as in the case of a new mempool just created as in the case of EEXIST (=17) > we don't want to execute "goto out" and fall through to do > > dev->rxq_size = dev->requested_rxq_size; > dev->txq_size = dev->requested_txq_size; > ... > > With these code changes it seems to work, at the beginning I have MTU=1500 > and I set it to 1000: > > # ovs-vsctl list interface dpdk0 | grep mtu > mtu : 1500 > mtu_request : [] > > # ovs-vsctl set interface dpdk0 mtu_request=1000 > my log says > netdev_dpdk|DBG|Requesting a mempool of 40992 mbufs for netdev dpdk0 with 1 > Rx and 11 Tx queues, socket id:0. > netdev_dpdk|DBG|A mempool with name ovs_62a2ca2f_0_2030_40992 already exists > at 0x7fad9d77dd00. > dpdk|INFO|PMD: ixgbe_dev_link_status_print(): Port 0: Link Up - speed 0 Mbps > - half-duplex > > # ovs-vsctl list interface dpdk0 | grep mtu > mtu : 1000 > mtu_request : 1000 > > Does that make sense? > Looks ok to me. Kevin. > Thanks, > -Antonio > >> >> Kevin. >> >>> Antonio >>> >>>> -----Original Message----- >>>> From: ovs-dev-boun...@openvswitch.org [mailto:ovs-dev- >> boun...@openvswitch.org] >>>> On Behalf Of Fischetti, Antonio >>>> Sent: Wednesday, October 11, 2017 9:04 AM >>>> To: Róbert Mulik <robert.mu...@ericsson.com>; d...@openvswitch.org >>>> Subject: Re: [ovs-dev] [PATCH v3 1/5] netdev-dpdk: fix mempool management >> with >>>> vhu client. >>>> >>>> Thanks Robert for reporting this and for all the clear details you >>>> provided. >>>> I'll look into this and get back to you. >>>> >>>> Antonio >>>> >>>>> -----Original Message----- >>>>> From: Róbert Mulik [mailto:robert.mu...@ericsson.com] >>>>> Sent: Tuesday, October 10, 2017 4:19 PM >>>>> To: Fischetti, Antonio <antonio.fische...@intel.com>; d...@openvswitch.org >>>>> Subject: RE: [ovs-dev] [PATCH v3 1/5] netdev-dpdk: fix mempool management >>>> with >>>>> vhu client. >>>>> >>>>> Hi Antonio, >>>>> >>>>> Last week I run into this mempool issue during the development of a new >>>>> feature. I have made a bugfix, but then we saw yours too, so I tested if >>>>> it >>>>> solves my problem. It did, but I realized another problem with it. The >>>> mempool >>>>> name generation is partly based on the MTU size, which is handled in 1024 >>>> bytes >>>>> long ranges. For example MTU 1000 and 1500 are in the same range, 2000 and >>>> 2500 >>>>> are in a different range. So I tested this patch and got the following. >>>>> >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 2500 >>>>> mtu_request : 2500 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=2000 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 2500 >>>>> mtu_request : 2000 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=1500 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 1500 >>>>> mtu_request : 1500 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=1000 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 1500 >>>>> mtu_request : 1000 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=2000 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 2000 >>>>> mtu_request : 2000 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=1000 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 1000 >>>>> mtu_request : 1000 >>>>> # ovs-vsctl set interface dpdk0 mtu_request=1500 >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 1000 >>>>> mtu_request : 1500 >>>>> # service openvswitch-switch restart >>>>> # ovs-vsctl list interface dpdk0 |grep mtu >>>>> mtu : 1500 >>>>> mtu_request : 1500 >>>>> >>>>> >>>>> This was my setup: >>>>> Bridge br-prv >>>>> Port bond-prv >>>>> Interface "dpdk0" >>>>> type: dpdk >>>>> options: {dpdk-devargs="0000:05:00.0", n_rxq_desc="1024", >>>>> n_txq_desc="1024"} >>>>> ovs_version: "2.8.90" >>>>> >>>>> And I used DPDK v17.08. >>>>> >>>>> >>>>> So, as it can be see from the example above, with the patch applied when a >>>> new >>>>> mtu_request is in the same range as the previously set MTU, then it has no >>>>> effect until service restart. The mtu_request has immediate effect when it >> is >>>>> in different range as the previously set MTU. Or did I miss something >> during >>>>> the testing? >>>>> >>>>> My patch what I used last week does the following. During reconfiguration >> the >>>>> mempool is always deleted before a new one is created. It solved the >> problem >>>>> without side effects, but it is not optimized (always recreates the >>>>> mempool >>>>> when this function is called). >>>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c >>>>> index c60f46f..de38f95 100644 >>>>> --- a/lib/netdev-dpdk.c >>>>> +++ b/lib/netdev-dpdk.c >>>>> @@ -621,6 +621,7 @@ netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) >>>>> uint32_t buf_size = dpdk_buf_size(dev->requested_mtu); >>>>> struct dpdk_mp *mp; >>>>> >>>>> + dpdk_mp_put(dev->dpdk_mp); >>>>> mp = dpdk_mp_get(dev, FRAME_LEN_TO_MTU(buf_size)); >>>>> if (!mp) { >>>>> VLOG_ERR("Failed to create memory pool for netdev " >>>>> @@ -629,7 +630,6 @@ netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) >>>>> rte_strerror(rte_errno)); >>>>> return rte_errno; >>>>> } else { >>>>> - dpdk_mp_put(dev->dpdk_mp); >>>>> dev->dpdk_mp = mp; >>>>> dev->mtu = dev->requested_mtu; >>>>> dev->socket_id = dev->requested_socket_id; >>>>> >>>>> >>>>> What do you think about this solution? >>>>> >>>>> Regards, >>>>> Robert >>>> _______________________________________________ >>>> dev mailing list >>>> d...@openvswitch.org >>>> https://mail.openvswitch.org/mailman/listinfo/ovs-dev > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev