Comment 51 for bug 1736390

Thanks,
installed that in the test env, after a manual reboot I got:

$ uname -a
Linux autopkgtest 4.15.0-34-generic #38~lp1736390Commit12064551Reverted SMP Thu Sep 13 13:28:33 UTC i686 i686 i686 GNU/Linux

The change is persistent into the autopkgtest:
autopkgtest [05:11:17]: testbed running kernel: Linux 4.15.0-34-generic #38~lp1736390Commit12064551Reverted SMP Thu Sep 13 13:28:33 UTC

The test kernel works fine where the other one failed.
To be sure I ran it multiple times and with different cpu options enables in KVM (e.g. to also run the DPDK tests which need sse3).

But they all worked, no crash.
That said - yes reverting that change seems to be the solution.
Yet for what was it needed and what would break if it is reverted?

commit 120645513f55a4ac5543120d9e79925d30a0156f
Author: Jarno Rajahalme <email address hidden>
Date: Fri Apr 21 16:48:06 2017 -0700

    openvswitch: Add eventmask support to CT action.

    Add a new optional conntrack action attribute OVS_CT_ATTR_EVENTMASK,
    which can be used in conjunction with the commit flag
    (OVS_CT_ATTR_COMMIT) to set the mask of bits specifying which
    conntrack events (IPCT_*) should be delivered via the Netfilter
    netlink multicast groups. Default behavior depends on the system
    configuration, but typically a lot of events are delivered. This can be
    very chatty for the NFNLGRP_CONNTRACK_UPDATE group, even if only some
    types of events are of interest.

    Netfilter core init_conntrack() adds the event cache extension, so we
    only need to set the ctmask value. However, if the system is
    configured without support for events, the setting will be skipped due
    to extension not being found.

That is odd, I thought in the past we had identified an Ubuntu-sauce patch, but that is a normal upstream change.
I'd hope that other are affected as well and this is fixed, or could it be that we are affected by 1206455 due to some Ubuntu-sauce?

For the sake of checking if latest upstream (no sauce and 4.19-rc3) might be better I ran the latest mainline kernel.

autopkgtest [05:21:50]: testbed running kernel: Linux 4.19.0-041900rc3-generic #201809120832 SMP Wed Sep 12 12:47:16 UTC 2018

But that is crashing still.

@James: can you estimate what we loose on non-i386 when reverting that change for now?
@Joseph: what would we do now, report upstream - if so what exactly a description and link sent to the author and the ML as we don#t have a fix yet?