> On May 31, 2023, at 3:04 PM, Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Tue, May 23, 2023 at 07:18:18PM +0000, Chuck Lever III wrote:
>
>> The core address resolution code wants to find an L2 address
>> for the egress device. The underlying ib_device, where a made-up
>> GID might be stored, is not involved with address resolution
>> AFAICT.
>
> Where are you hitting this?
kworker/2:0-26 [002] 551.962874: funcgraph_entry: | addr_resolve() {
kworker/2:0-26 [002] 551.962874: bprint: addr_resolve: resolve_neigh=true resolve_by_gid_attr=false
kworker/2:0-26 [002] 551.962874: funcgraph_entry: | addr4_resolve.constprop.0() {
kworker/2:0-26 [002] 551.962875: bprint: addr4_resolve.constprop.0: src_in=0.0.0.0:35173 dst_in=100.72.1.2:20049
kworker/2:0-26 [002] 551.962875: funcgraph_entry: | ip_route_output_flow() {
kworker/2:0-26 [002] 551.962875: funcgraph_entry: | ip_route_output_key_hash() {
kworker/2:0-26 [002] 551.962876: funcgraph_entry: | ip_route_output_key_hash_rcu() {
kworker/2:0-26 [002] 551.962876: funcgraph_entry: 4.526 us | __fib_lookup();
kworker/2:0-26 [002] 551.962881: funcgraph_entry: 0.264 us | fib_select_path();
kworker/2:0-26 [002] 551.962881: funcgraph_entry: 1.022 us | __mkroute_output();
kworker/2:0-26 [002] 551.962882: funcgraph_exit: 6.705 us | }
kworker/2:0-26 [002] 551.962882: funcgraph_exit: 7.283 us | }
kworker/2:0-26 [002] 551.962883: funcgraph_exit: 7.624 us | }
kworker/2:0-26 [002] 551.962883: funcgraph_exit: 8.395 us | }
kworker/2:0-26 [002] 551.962883: funcgraph_entry: | rdma_set_src_addr_rcu.constprop.0() {
kworker/2:0-26 [002] 551.962883: bprint: rdma_set_src_addr_rcu.constprop.0: ndev=0xffff91f5135a4000 name=tailscale0
kworker/2:0-26 [002] 551.962884: funcgraph_entry: | copy_src_l2_addr() {
kworker/2:0-26 [002] 551.962884: funcgraph_entry: 0.984 us | iff_flags2string();
kworker/2:0-26 [002] 551.962885: bprint: copy_src_l2_addr: ndev=0xffff91f5135a4000 dst_in=100.72.1.2:20049 flags=UP|POINTOPOINT|NOARP|MULTICAST
kworker/2:0-26 [002] 551.962885: funcgraph_entry: | rdma_copy_src_l2_addr() {
kworker/2:0-26 [002] 551.962886: funcgraph_entry: 0.148 us | devtype2string();
kworker/2:0-26 [002] 551.962887: bprint: rdma_copy_src_l2_addr: name=tailscale0 type=NONE src_dev_addr=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 broadcast=00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ifindex=3
kworker/2:0-26 [002] 551.962887: funcgraph_exit: 1.488 us | }
kworker/2:0-26 [002] 551.962887: bprint: copy_src_l2_addr: network type=IB
kworker/2:0-26 [002] 551.962887: funcgraph_exit: 3.636 us | }
kworker/2:0-26 [002] 551.962887: funcgraph_exit: 4.275 us | }
Address resolution finds the right device, but there's
a zero-value L2 address. Thus it cannot form a unique
GID from that. Perhaps there needs to be a call to
query_gid in here?
--
Chuck Lever
