Re: [gdm-list] gdm-binary CPU usage

[Brian Cameron <Brian Cameron Sun COM>]

Brandon:

>     We recently switched from the default dtlogin over to GDM at work as 
> we were having significant issues with DNS through XDMCP using the old 
> dtlogin process and GDM works extremley well and solved all our issues 
> with regard to DNS so thank you very much to the author for that!

Great, good news.

>     Recently we have been having an issue where after having our Solaris 
> 10 box up for a week or two the master gdm-binary process and 1 or 2 of 
> its children begin eating up CPU and it exponentially gets worse as time 
> goes on. I think it may be related to users who do not log out correctly 
> or for some reason the gdm-binary child isnt terminated correctly upon 
> logout. if I do a PS and GREP for gdm-binary you can see that the 
> processes using all the CPU are the ones that have been up the longest, 
> like on the order of days.

Please make sure you have the latest Solaris 10 update installed?  If
not, then I'd recommend updating to the latest to make sure you have
all the latest bug fixes.

Could you run "pstack (pid)" of the process eating CPU so we can see
what the process(es) are doing when it is consuming so much CPU?

Do you have the face browser turned on?  If so, and if you have 
IncludeAll turned on, and a lot of users on your system, then GDM
can consume a lot of CPU trying to get face images for all users.

Aside from the above, I haven't heard of any common issues that cause
GDM on Solaris 10 to consume a lot of CPU.

> I searched the list archives and google and found a couple hints at 
> setting AlwaysRestartServer to true in order to shut down xsessions upon 
> logout and re-create the process, this setting was set true already in 
> our config file.

Right, this setting should be true by default on Solaris.  Also, if this
were the problem, I'd expect the Xserver process to be the one causing
problems not the GDM processes.

> I also read that there is a feature in solaris that 
> allows the x server to run as the user rather than root, is this 
> refering to allowing gdm-binary to run as the user rather than root? if 
> so, we would like to enable this but we cant find instructions on how to 
> set it up could anyone point me in the right direction on that as well? 
> Anyone else run into this gdm-binary CPU usage problem? Any ideas on how 
> to prevent gdm-binary from running amok like that?

This feature causes the Xserver process to run as the user, not as root.
Are you seeing the Xserver process running as root?  If so, are you
using the latest S10 Update release?  I believe this fix went into
a S10 update release and may not be in older S10 releases.

>    We also ran into a new issue today in which the server has stopped 
> accepting conncetions despite having bumped the max allowed sessions up 
> to 100. users will attempt to login to the server but the XDMCP request 
> never gets answered by the server so our client xdmcp request times out.

Note it is probably best to run gdm-restart after changing configuration
though this will cause all active logins to exit.  Or you could reboot.
Do you still see the problems after doing this?

If you use gdmsetup to change configuration, then the daemon process is
usually smart enough to recognize the change right away, though there
are some bugs that do require a restart after particular config changes.

Brian