> > > On 11/24/2016 04:34 PM, Loftus, Ciara wrote: > >> > >> > >> On 11/24/2016 03:59 PM, Loftus, Ciara wrote: > >>>> > >>>> On 11/24/2016 03:20 PM, Ciara Loftus wrote: > >>>>> This commit announces support for DPDK 16.11. Compaitibilty with > DPDK > >>>>> v16.07 is not broken yet thanks to only minor code changes being > >> needed > >>>>> for the upgrade. > >>>>> > >>>>> Signed-off-by: Ciara Loftus <[email protected]> > >>>>> --- > >>>>> .travis/linux-build.sh | 2 +- > >>>>> INSTALL.DPDK-ADVANCED.rst | 4 ++-- > >>>>> INSTALL.DPDK.rst | 18 +++++++++--------- > >>>>> NEWS | 1 + > >>>>> lib/netdev-dpdk.c | 3 ++- > >>>>> 5 files changed, 15 insertions(+), 13 deletions(-) > >>>> <snip /> > >>>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c > >>>>> index de78ddd..7564ad7 100644 > >>>>> --- a/lib/netdev-dpdk.c > >>>>> +++ b/lib/netdev-dpdk.c > >>>>> @@ -2593,7 +2593,8 @@ netdev_dpdk_vhost_class_init(void) > >>>>> rte_vhost_driver_callback_register(&virtio_net_device_ops); > >>>>> rte_vhost_feature_disable(1ULL << VIRTIO_NET_F_HOST_TSO4 > >>>>> | 1ULL << VIRTIO_NET_F_HOST_TSO6 > >>>>> - | 1ULL << VIRTIO_NET_F_CSUM); > >>>>> + | 1ULL << VIRTIO_NET_F_CSUM > >>>>> + | 1ULL << > >>>>> VIRTIO_RING_F_INDIRECT_DESC); > >>>>> ovs_thread_create("vhost_thread", start_vhost_loop, NULL); > >>>>> > >>>>> ovsthread_once_done(&once); > >>>>> > >>>> Any reason you disable indirect descs? > >>>> Did you measure performance degradation with it? > >>> > >>> I measured a slight decrease ~-6% for the use case I tested. > >> Ok, could you provide more details about this use-case? > >> I'm interested to know which cases (don't) benefit of this feature. > > > > Single flow 64B packets unidirectional loopback test (dpdk -> vhost, vhost - > > dpdk) with testpmd forwarding between vhost ports in the VM. Mergeable > buffers disabled. > Ok, thanks. > Is testpmd in IO mode?
Correct, default mode. > > Anyway, this is good to see that DPDK version upgrade has no blockers. > With indirect disabled, how performance compare to v16.07? I'm taking rough measurements but 16.07 performs slightly better for this case - ~+2% on indirect disabled, ~+8% on indirect enabled. Thanks, Ciara > > > > >> > >>> Either way, if it is to be enabled it should be enabled in a separate > >>> patch. > >> Well, I'm not sure. > >> I think this is not a good way to disable features, because once > >> OVS packaged, we cannot enable it anymore. > > > > My reasoning not to enable it in this patch (other than the degradation) is > because the purpose of this patch is the DPDK upgrade. We could have a > second patch "enable indirect descriptors for vHost" for example, as > suggested by Ilya previously: > > https://mail.openvswitch.org/pipermail/ovs-dev/2016- > October/324586.html > Ok. > > > >> > >> It should be the role of the management tool to disable it by default, > >> by configuring the Qemu params properly if needed (indirect_desc=off). > >> Doing this, it could still be enabled without rebuilding the package if > >> it benefits some use-cases. > >> > >> I would think this is the same for the other features that are disabled, > >> as soon as they don't break functionality. If other features break > >> functionality, it should be reported so that it gets fixed. > >> > >> Moreover, we are looking at cross-version migration for vhost currently, > >> and rte_vhost_feature_disable is problematic, because it prevent us to > >> export virtio features supported by a given DPDK version reliably at > >> build time. > > > > I see your reasoning too. Would like to hear input from other folks in the > community before I respin. > Yes, sure. > And cross-version migration is currently being discussed. > > Thanks, > Maxime > > > > Thanks, > > Ciara > > > >> > >> Cheers, > >> Maxime _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
