High CPU on latest nightly

[drago01]

On Wed, Mar 4, 2015 at 2:40 AM, Adam Williamson
<adamwill at fedoraproject.org> wrote:
> On Tue, 2015-03-03 at 17:00 -0800, Adam Williamson wrote:
>> On Tue, 2015-03-03 at 04:59 -0500, Kamil Paral wrote:
>> > > On Mon, 2015-03-02 at 22:46 +0000, Alexander Bisogianis wrote:
>> > > > > I'm not seeing anything like that on my F22 desktop.
>> > > > >
>> > > >
>> > > > I mean while installing F22, all four CPUs on the KVM host
>> > > > (F21) are constantly at 100% usage.
>> > > >
>> > > > Running top in TTY2, while F22 is installing, I see:
>> > > >
>> > > > Xorg using constantly CPU 60%-70%
>> > > > 2 anaconda processes using constantly CPU 60%-70%
>> > > >
>> > > > I can understand anaconda, but Xorg?
>> > >
>> > > IIRC there's a spinner or something similar visible during
>> > > install; it could well be caused by that. I even think I caught
>> > > some discussion about a patch to disable it during automated
>> > > test runs or something in #anaconda the other day...
>> >
>> > Alexander, try running the installation with this boot option:
>> >
>> > inst.updates=https://kparal.fedorapeople.org/tmp/no-spinner.img
>> >
>> > It should disable spinner animation. Then compare the CPU usage. I
>> > still haven't gotten to reporting it as a bug, but it's true that
>> > the spinner seems to be a *gigantic* performance hog, making all
>> > our installations take much longer, especially in VMs.
>>
>> Now I come to notice it, GTKSpinners don't seem to spin at all in
>> TC7 and TC8. They do spin on my desktop. Not sure if there's a
>> package difference or it's a KVM vs. real hardware thing, but
>> they're broken with at least both 'vga' and 'qxl' in a KVM. Just
>> burning a USB stick to see if it's the same on bare metal. Probably
>> GTK+ 3.15.9 is involved.
>
> Huh, it's odder than that - GtkSpinners apparently don't spin in GNOME
> on a KVM, but they *do* spin in the installer environment.

That's not really a bug. There is a xsettings key
"Gtk/EnableAnimations" that gets disabled if the system is using
software rendering (or if it is a remote system) to improve
performance.
There is no "full gnome" in the installer environment so nothing
disables the key but in the user session ...