Ubuntu
kwin package

Booting from Kubuntu >=16.04 32bit Live-DVD crashes on CPUs w/o SSE2

Bug #1614308 reported by Lars Bischoff
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This bug affects 1 person
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kubuntu-meta (Ubuntu)
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kwin (Ubuntu)
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Bug Description

When booting from a freshly burned Live DVD using images
 kubuntu-16.04-desktop-i386.iso or
 kubuntu-16.04.1-desktop-i386.iso
kwin always crashes on my system.

Booting works fine until the plasma background image is appearing.
Also the selection window whether you want to "try" or "install" Kubuntu shows up, but only without window frame. At about the same time I get a crash notification that kwin has crashed.
If I click on "restart" in the crash notification, then after some trials another window (without frame) says: "KWin is unstable. It seems to have crashed several times in a row." and suggests to select another window manager. Of course the Kubuntu ISO does not contain another window manager.

The used hardware is:
AMD Athlon XP 3000+ CPU
VIA KT400 Chipset
Mainboard MSI KT4V-L
Gfx: nVidia Geforce 7600 GT (AGP8x card: XFX GF 7600 GT 560M 256MB)

BTW: Booting Ubuntu 16.04 32bit DOES work on the very same system.

Update, 2016-10-23:
It turned out that it is highly likely that this issue is caused by the missing "SSE2" support of the CPU in question.
Is kwin supposed to not work on non SSE2 CPUs ??

See original description
Lars Bischoff (lbischoff)
no longer affects: iso (Ubuntu)
Revision history for this message
Lars Bischoff (lbischoff) wrote :

1st thought was, that this might be related to the nVidea GFX Card.
But replacing it by a Radeon HD 3450 did not help.
kwin crashes in the exactly same way as with the nVidea card.

Revision history for this message
Lars Bischoff (lbischoff) wrote :

next trial was booting from Kubuntu 14.04.5 LTS Live DVD.
And that indeed works nicely on the mentioned hardware.

Revision history for this message
Lars Bischoff (lbischoff) wrote :

After some experimenting and google'ing, I think I figured out, what the reason for this issue is:

kwin of Plasma 5 seems to require the "SSE2" CPU extension, which my Athlon XP 3000+ CPU does not have (it just has MMX, 3DNow! and SSE).

See also here:
https://bugs.mageia.org/show_bug.cgi?id=15594
This sounds very related to my issue.

So now the question is:
Is it intended that Kubuntu with Plasma 5 only runs on SSE2 CPUs or is it a bug (maybe wrong Package used?)

If it is intended, then this should be
  1) communicated on the web-page!
  2) catched during Live-DVD boot instead of letting kwin crash.
If it is a bug, it should be fixed of course. :-)

I hope for the latter because I would really love to run Plasma 5 / Kubuntu on that particular machine.

summary: - kwin crashes when booting from Kubuntu 16.04 32bit Live-DVD
+ Booting from Kubuntu >=16.04 32bit Live-DVD crashes on CPUs w/o SSE2
Lars Bischoff (lbischoff)
description: updated
tags: added: i386 iso-testing kubuntu xenial yakkety
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