Thanks Kevin for your feedback. Below some details on what happens, how to replicate the issue and some comments inline.
-Antonio > -----Original Message----- > From: Kevin Traynor [mailto:[email protected]] > Sent: Monday, October 2, 2017 6:38 PM > To: Fischetti, Antonio <[email protected]>; [email protected] > Cc: Aaron Conole <[email protected]> > Subject: Re: [PATCH v2 1/4] netdev-dpdk: fix mempool management with vhu > client. > > On 09/28/2017 03:28 PM, [email protected] wrote: > > From: Antonio Fischetti <[email protected]> > > > > In a PVP test where vhostuser ports are configured as > > clients, OvS crashes when QEMU is launched. > > This patch avoids the repeated calls to netdev_change_seq_changed > > after the requested mempool is already acquired. > > > > Can you explain what is happening in this bug? I can't reproduce it [Antonio] When QEMU is being launched, ovs crashes with the following stacktrace: https://mail.openvswitch.org/pipermail/ovs-dev/2017-September/339343.html In case the requested mempool already exists, netdev_dpdk_mempool_configure returns 0 => netdev_change_seq_changed is called. The issue happens with vhostuser 'client' ports: - the vhu ports must be of dpdkvhostuserclient type - so the QEMU command must contain 'server' like qemu-system-x86_64 .... path=$CLIENT_SOCK_DIR/$SOCK0,server Below other details on my setup. 1 PMD ----- ovs-vsctl --no-wait set Open_vSwitch . other_config:pmd-cpu-mask=8 Ports ----- ovs-vsctl add-port br0 dpdk0 -- set Interface dpdk0 type=dpdk options:dpdk-devargs=$NIC0 ovs-vsctl add-port br0 dpdk0 -- set Interface dpdk1 type=dpdk options:dpdk-devargs=$NIC1 ovs-vsctl add-port br0 dpdkvhostuser0 -- set Interface dpdkvhostuser0 type=dpdkvhostuserclient ovs-vsctl set Interface dpdkvhostuser0 options:vhost-server-path="/tmp/dpdkvhostuser0" ovs-vsctl add-port br0 dpdkvhostuser1 -- set Interface dpdkvhostuser1 type=dpdkvhostuserclient ovs-vsctl set Interface dpdkvhostuser1 options:vhost-server-path="/tmp/dpdkvhostuser1" I'm using DPDK v17.05 and QEMU v2.7.0. Other details are below right after the patch description. > and > the mempool for vhost ports should only be reconfigured if the number of > queues or socket has changed. > > > CC: Kevin Traynor <[email protected]> > > CC: Aaron Conole <[email protected]> > > Reported-by: Ciara Loftus <[email protected]> > > Fixes: d555d9bded5f ("netdev-dpdk: Create separate memory pool for each > port.") > > Signed-off-by: Antonio Fischetti <[email protected]> > > --- > > To replicate the bug scenario: > > > > PVP test setup > > -------------- > > CLIENT_SOCK_DIR=/tmp > > SOCK0=dpdkvhostuser0 > > SOCK1=dpdkvhostuser1 > > > > 1 PMD > > Add 2 dpdk ports, n_rxq=1 > > Add 2 vhu ports both of type dpdkvhostuserclient and specify vhost-server- > path > > ovs-vsctl set Interface dpdkvhostuser0 options:vhost-server- > path="$CLIENT_SOCK_DIR/$SOCK0" > > ovs-vsctl set Interface dpdkvhostuser1 options:vhost-server- > path="$CLIENT_SOCK_DIR/$SOCK1" > > > > Set port-based rules: dpdk0 <--> vhu0 and dpdk1 <--> vhu1 > > add-flow br0 in_port=1,action=output:3 > > add-flow br0 in_port=3,action=output:1 > > add-flow br0 in_port=4,action=output:2 > > add-flow br0 in_port=2,action=output:4 > > > > Launch QEMU > > ----------- > > As OvS vhu ports are acting as clients, we must specify 'server' in the next > command. > > VM_IMAGE=<path/to/your/vm/image> > > > > sudo -E taskset 0x3F00 $QEMU_DIR/x86_64-softmmu/qemu-system-x86_64 -name > > us- > vhost-vm1 -cpu host -enable-kvm -m 4096M -object memory-backend- > file,id=mem,size=4096M,mem-path=/dev/hugepages,share=on -numa node,memdev=mem > - > mem-prealloc -smp 4 -drive file=$VM_IMAGE -chardev > socket,id=char0,path=$CLIENT_SOCK_DIR/$SOCK0,server -netdev type=vhost- > user,id=mynet1,chardev=char0,vhostforce -device virtio-net- > pci,mac=00:00:00:00:00:01,netdev=mynet1,mrg_rxbuf=off -chardev > socket,id=char1,path=$CLIENT_SOCK_DIR/$SOCK1,server -netdev type=vhost- > user,id=mynet2,chardev=char1,vhostforce -device virtio-net- > pci,mac=00:00:00:00:00:02,netdev=mynet2,mrg_rxbuf=off --nographic > > > > Expected behavior > > ----------------- > > With this fix OvS shouldn't crash. > > --- > > lib/netdev-dpdk.c | 12 ++++++++---- > > 1 file changed, 8 insertions(+), 4 deletions(-) > > > > diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c > > index c60f46f..dda3771 100644 > > --- a/lib/netdev-dpdk.c > > +++ b/lib/netdev-dpdk.c > > @@ -621,6 +621,10 @@ netdev_dpdk_mempool_configure(struct netdev_dpdk *dev) > > uint32_t buf_size = dpdk_buf_size(dev->requested_mtu); > > struct dpdk_mp *mp; > > > > + if (dev->requested_socket_id == dev->socket_id > > + && dev->requested_mtu == dev->mtu) { > > + return EEXIST; > > + } > > But you would want to get a new mempool if the number of queues have > changed, as that is part of the calculation for the size of the mempool. > MIN_NB_MBUF was added to over provision as a safety so you'd probably > get away with it but you should be requesting a new mempool with the > correctly calculated num of mbufs. [Antonio] I get your point, if the nr of queues has changed, then socket and mtu are unchanged. But a new nr of mbuf must be computed to accommodate packets for the different queues. That affects the mp name too. So we do need to call dpdk_mp_create to create a new mp. > > It seems like this code is trying to add back in the code to prevent > rte_pktmbuf_pool_create being called again for the same values. In the > patchset that this fixes it is removed and the EEXISTS return from > rte_pktmbuf_pool_create are handled instead. I'm not sure that both > mechanisms are needed. [Antonio] I'll try to rework by managing the EEXIST case only. > > > mp = dpdk_mp_get(dev, FRAME_LEN_TO_MTU(buf_size)); > > if (!mp) { > > VLOG_ERR("Failed to create memory pool for netdev " > > @@ -3207,7 +3211,7 @@ netdev_dpdk_reconfigure(struct netdev *netdev) > > rte_eth_dev_stop(dev->port_id); > > > > err = netdev_dpdk_mempool_configure(dev); > > - if (err) { > > + if (err && err != EEXIST) { > > goto out; > > } > > > > @@ -3247,10 +3251,10 @@ dpdk_vhost_reconfigure_helper(struct netdev_dpdk > *dev) > > netdev_dpdk_remap_txqs(dev); > > > > err = netdev_dpdk_mempool_configure(dev); > > - if (err) { > > - return err; > > - } else { > > + if (!err) { > > netdev_change_seq_changed(&dev->up); > > + } else if (err != EEXIST){ > > + return err; > > } > > > > if (netdev_dpdk_get_vid(dev) >= 0) { > > _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
