On Tue, Jan 23, 2018 at 6:35 AM, Roman Kapl <c...@rkapl.cz> wrote: > On 12/18/2017 07:20 AM, Xin Long wrote: >> >> Unlike ip tunnels, now vxlan doesn't do any pmtu update for >> upper dst pmtu, even if it doesn't match the lower dst pmtu >> any more. >> >> The problem can be reproduced when reducing the vxlan lower >> dev's pmtu when running netperf. In jianlin's testing, the >> performance went to 1/7 of the previous. >> >> This patch is to update the upper dst pmtu to match the lower >> dst pmtu on tx path so that packets can be sent out even when >> lower dev's pmtu has been changed. >> >> It also works for metadata dst. > > Sorry for resurrecting the conversation, but what exactly was meant by this > "works metadata dst" remark? I am currently having kernel crashes related to > ops->update_pmtu == NULL on VXLAN xmit and I am using tunnel metadata set by > act_tunnel_key. Before this patch, it was OK. You are right, it is introudced by this patch.
Jiri Benc mentioned about this patch on md_dst, then I wrote a test case with ip route running over it. It worked well, now I realized I cleaned up the env too fast. Pls also fix it on geneve_xmit. thanks. > > My first thought was to add `if (ops->update_pmtu != NULL)`, but it appears > some thought was given to this. Or maybe md_dst_ops should have update pmtu? md_dst_ops doesn't support pmtu, I had no plans for it yet by now. > > Thanks, Roman Kapl
