Password field feedback slow at times

[Hernando Torque]

When entering the user password, the dots in the password field sometimes take some time to appear and are not in sync with my typing. As there currently is no indication of whether or not the password field has the focus this is a bit annoying because I never know if I just didn't focus the field, if the greeter is broken, or the dots just take some time to appear.

I monitored the system remotely and couldn't find any hints that the lag is caused by CPU load spikes or alike.

TEST CASE:
* Boot the system
* At the Unity greeter type your password

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity-greeter 0.0.2-0ubuntu2
ProcVersionSignature: Ubuntu 3.0.0-8.11-generic 3.0.1
Uname: Linux 3.0.0-8-generic x86_64
Architecture: amd64
Date: Wed Aug 17 17:22:00 2011
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Alpha amd64 (20110630)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: unity-greeter
UpgradeStatus: No upgrade log present (probably fresh install)

[Lucazade (lucazade)]

get the same here

[Robert Ancell (robert-ancell)]

Could you run unity-greeter --test-mode and see if the problem continues?

Are there any indications that anything else is running at the same time? Wait a minute after booting up and see if the performance is the same.

Do you have fast or slow computers? High or low resolutions?

[Hernando Torque (htorque)]

The behavior seems to have changed and now I'm getting delays only upon greeter start, while X shows some CPU spikes. Afterwards the text field responds fine.

No problems with unity-greeter --test-mode, fast computers, resolutions are 1920x1080 and 1600x900.

[Jason Warner (jasoncwarner)]

I a similar experience and when it happened for me, the mouse was also very laggy. So laggy in fact that I had to abandon moving the mouse at all and just get out of the greeter.

It was happening pretty consistently for about 2 days and then it went away as I was trying to debug it. Trying to replicate now with Robert's help.

[Robert Ancell (robert-ancell)]

We've been doing a lot of testing recently to try and track down the performance issues.

1. There were some known slow parts (rendering the background and the indicators) which were being left to last to optimise. These are now threaded on the master version.

2. We've tried using additional logging and dropping features on Jason Warner's box to see if we can pinpoint the slowness. I'll attach the most recent log which show ~2.9s calling gtk_widget_show () and a slow framerate. This test build had the indicators and the background rendering/animation disabled so there's really not a lot of CPU/IO that the greeter should be using.

[Jonathan Lange (jml)]

Note that for me (as reported in my duped bug 838777), it's not just the Password field that has slow feedback. Even mouse movements are tracked slowly.

[Juho Teperi (deraen)]

If your mouse is also laggy might be that it's caused by X probing your video outputs. That's the cause for me when using computer with Intel Sandy Bridge gpu.

Check if opening Display properties or running xrandr causes cpu spike and mouse laggines.

[Hernando Torque (htorque)]

Yes, I can confirm #9 on Arrandale and Sandy Bridge (Intel HD 2000 and 3000) - opening the display properties causes mouse lagging and a bit of CPU load, but it is this connected to this bug? The LightDM GTK greeter doesn't show any lagging after all.

[Juho Teperi (deraen)]

I did some boots with bootchart that show Xorg doing lot work during boot. Xorg log shows that those spikes relate to randr probes.

Might be that the unity-greeter is starting some processes (e.g. gnome-settings-daemon) that call randr and the gtk-greeter doesn't start those? Still, I think those probes shouldn't cause any cpu spikes/lagginess.

Default (these are with mainline kernel and some i915 options but default kernel w/o options wasn't any better):
- http://dl.dropbox.com/u/14396467/juho-laptop-oneiric-20110915-1.png
Disabled extra outputs at xorg.conf (http://pastebin.com/dnGkq8cU):
- http://dl.dropbox.com/u/14396467/juho-laptop-oneiric-20110916-7.png
Xorg log showing randr probes, lines 453-494:
- http://pastebin.com/skKi8nvq

[Hernando Torque (htorque)]

Getting the same picture here. Attaching a bootchart crop of Oneiric with kernel 2.6.38 vs. 3.0.0 (this is with auto-login, but shows the same characteristics with the greeter) - X start is considerably longer (total boot times: 14 vs 40 seconds with a SSD...).

[Hernando Torque (htorque)]

X doesn't seem to do anything when the GTK greeter runs, while it does those CPU spiking probes whit the Unity greeter. Screenshot attached.

[Hernando Torque (htorque)]

FWIW, I tested a Nvidia GPU in the same system with 'nvidia-current' and 'nouveau'. The Nvidia BLOB didn't show any lagging or increased Xorg CPU usage. However, Nouveau showed the same as Intel - screenshot attached.

[Sebastien Bacher (seb128)]

those charts seem to indicate the issue is not a lightdm or desktop one but rather a kernel bug, gnome-settings-daemon seems to do some xorg probes but those shouldn't take over 1 second of ressources each.

[Hernando Torque (htorque)]

I'm not sure how Chris Coulson's work on gnome-settings-daemon will influence this bug (I don't see a g-s-d process running while the greeter acts up), but can this one be closed then (for the greeter, as the password field and pointer are still slow to response right after starting the greeter)?

[Sebastien Bacher (seb128)]

so Chris did work on bug #854101 (optimization for g-s-d) which quite improved login for him, he uploaded those in ubuntu-desktop ppa for those who want to test, https://launchpad.net/~ubuntu-desktop/+archive/ppa (be careful there is also a candidate compiz update for stacking issues there)

[Sebastien Bacher (seb128)]

Hernando, why do you want to close this one if you think the issues are different?

[Hernando Torque (htorque)]

Because the password field being slow to respond and the mouse lagging don't seem to be caused by the unity-greeter (e.g., a simple kernel downgrade makes things work again). Not sure what can be done in unity-greeter to fix this.

As described in #11 - the probing of output ports seems to cause those issues (ignoring my unused DisplayPort and the non-existing HDMI port completely gets rid of the issue).

[Robert Ancell (robert-ancell)]

On testing with Jason's machine and disabling gnome-settings-daemon seemed to have a noticeable effect. Indications are the problem are external to unity-greeter/lightdm but it's worth keeping this bug open until we have it pinpointed.

[Sebastien Bacher (seb128)]

other interesting bug report:
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/854986
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/854986/

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/854986/comments/5 has a kernel to test that fixes quite some issues for others

[Sebastien Bacher (seb128)]

ups, the second bug is https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/855124

[Robert Ancell (robert-ancell)]

Is anyone still having this problem?

[Hernando Torque (htorque)]

At least no longer a problem with keyboard input. The mouse still reacts a bit choppy during the whole login process (not only the greeter) if I don't ignore the HDMI outputs via xorg.conf (bug 855124), but that's not a greeter problem.

[Launchpad Janitor (janitor)]

[Expired for unity-greeter (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for Unity Greeter because there has been no activity for 60 days.]