Comment # 167 on bug 1112824 from Timo Jyrinki

With confirming I largely mean the same you do by supporting :) I mean it's
confirmed there is a problem somewhere, and like I said I'm aware that this
video does not bring anything new to the table regarding fixing the problem.
Sometimes a video is just easier to consume than subjective observations over
multiple reboots, so I thought it'd be nice to have a direct comparison video.

My current best but not necessarily very good guess about the root cause for
the main performance degradation is some openSUSE specific patch(es) somewhere
in GNOME stack / libraries it uses. I'm also interested to see if there's
anything meaningful changing once transition from libmozjs52 to libmozjs60 is
complete - but I do see my TW is already using the latter for gnome-shell at
least.

Regarding some of the different factors you mentioned, I believe it's not
something Ubuntu has added, since Fedora (reportedly, I should test at some
point myself) performs as well as Ubuntu, and it's unlikely both Fedora and
Ubuntu would carry a non-upstreamed critical patch for such a long time.

The problem has also persisted for several months, so there has been ample time
for all the development versions of the distributions to at least somewhat get
"in sync", and all of them have had eg the same upstream GNOME 3.30 stack that
is currently in openSUSE Tumbleweed.

Some person in this thread has, in addition to the kernel parameters mentioned,
tried running Fedora kernel directly in openSUSE without a big help, so it
seems the kernel alone does not fix the lagginess. Surely the hyper-threading
disabling and IBRS -> retpoline help, but as seen on the video not enough to
get on par and no other distribution of course needs to disable
hyper-threading.

So here's just my summary of my current thinking. When I have extra time I
always try to think of something new to try or study, but my main requirement
was to get a usable desktop for doing other work with SUSE, which I now have
with the workarounds.

Something on my mind is to check that 20181015 <-> 20181018 snapshot delta
mentioned in comment #160 and see if the difference is as big as what I have
there on the video between distributions.