Red Hat Bugzilla – Bug 541878
X11 drawing operations very slow
Last modified: 2009-12-05 18:22:34 EST
Description of problem:
Video hardware: Intel Q45 integrated video
X feels very sluggish whenever actual drawing operations are taking place. top shows the Xorg process using up an entire CPU on it's own during that time. stracing shows that almost all time is spent in ioctl() calls to an open filehandle on /dev/dri/card0.
strace output and Xorg.0.log attached.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Boot into gdm
Drawing the GDM login screen is very slow, as is using the dialog
normal, fast behaviour
I just found out that almost every action in GDM (including just moving the mouse) results in new DCC probe messages appearing in /var/log/Xorg.0.log, describing the attached monitor.
Created attachment 374204 [details]
strace of Xorg during gdm user select
The only action performed during this strace was selection of a user name in the GDM login dialog by pressing Enter. The strace was terminated when the password selection dialog had appeared completely.
Created attachment 374205 [details]
xorg.conf (problem appears without xorg.conf, too)
Created attachment 374206 [details]
System is F12, but runs a rawhide kernel for testing. Problem also appears with kernel-PAE-184.108.40.206-127.fc12.i686.
All logs aboard.
This bug has been triaged
Fedora Bugzappers volunteer triage team
*** Bug 542097 has been marked as a duplicate of this bug. ***
The Xorg.0.log is very long with lots of repeated output of monitor detection. It's similar to https://bugzilla.redhat.com/show_bug.cgi?id=523646#c12
In https://bugzilla.redhat.com/show_bug.cgi?id=523646#c16 there is a report that kernel-220.127.116.11-145.fc12.x86_64 from updates-testing improves the situation. Since these two bugs look very similar, can someone here test that kernel too?
I only get bad performance at the login screen, and for me 18.104.22.168-145.fc12.x86_64 does not exhibit this behaviour.
For me the problem carries over to the desktop, and 22.214.171.124-145.fc12.PAE.i686 does not fix it (neither in GDM nor on the desktop)
I reported this bug here https://bugs.freedesktop.org/show_bug.cgi?id=24556 a while ago. I closed it but I should not have :
$ ls -lh /var/log/Xorg.0.log
-rw-r--r-- 1 root root 115M nov. 30 17:12 /var/log/Xorg.0.log
The bug still occurs with kernel 126.96.36.199-145.fc12 both at GDM login screen and while using firefox.
There is a sysprof log in the bug I filed in freedesktop bugzilla.
This was my description of the bug :
"Xorg is very sluggish on my intel X4500HD graphic card.
It's sluggish even in GDM at startup but it's worse when using firefox : it's
getting slower and slower until X seems to be freezed and hard reboot is
The uncompressed Xorg log weights 15M. sysprof points to drm_do_probe_ddc_edid.
I don't have a Xorg.conf and I don't use composition."
Isn't this bug the same as https://bugzilla.redhat.com/show_bug.cgi?id=523646 ?
It probably is.
I noticed something else, which may be related, running F11 (fully updated, shared home dir) on the same hardware. Soon after starting GNOME the kernel starts triggering a flood of udev events relating to the graphics card:
KERNEL[1259658330.187297] change /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
KERNEL[1259658330.201980] change /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
KERNEL[1259658330.209853] change /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
KERNEL[1259658330.214514] change /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
KERNEL[1259658330.218688] change /devices/pci0000:00/0000:00:02.0/drm/card0 (drm)
This just goes on and on. The system stays usable, though, it just triggers a ton of udev child processes.
*** This bug has been marked as a duplicate of bug 523646 ***
(In reply to comment #9)
> I only get bad performance at the login screen, and for me
> 188.8.131.52-145.fc12.x86_64 does not exhibit this behaviour.
I think I was lucky. 50% of the time I get the slow behaviour.