still having occasional hard desktop lockups

[Robin Laing]

Robin Laing wrote:
> Robert P. J. Day wrote:
>>   i know i've mentioned this before but i'm still having the
>> occasional desktop lockup where, when i'm trying to, say, just drag a
>> window, the cursor changes to the 4-way arrow and just *stays* that
>> way.  i can still move the cursor but it's painfully slow and there's
>> no way to get control of the system back short of power cycling.
>>
>>   IIRC, if i'm on a network, i can still ssh in so the underlying
>> system is still functioning, but there's no way to break out of X
>> anymore -- ctrl-alt-bs doesn't work.
>>
>>   is anyone else seeing this?  radeon driver.
>>
>> rday
>> -- 
>>
> 
> I am running into this with KDE desktop.  Exact symptoms.  The keyboard 
> is dead and I cannot do anything.  Even the Caps Lock key doesn't work. 
>  Num lock does work.
> 
> I tried to kill processes from a ssh but had no success.
> 
> No process loads to indicate where the problem is.  Nothing to report to 
> assist in a bug report.
> 
> What desktop are you running out of curiosity?
> 
> I have nVidia on an older system.  I have not run into this with my 
> 64bit system.
> 
> I have not had a lockup for a few days but before I get into a video 
> editing session (when my lockups are normal), I log out and back in.  It 
> seems to work great.
> 
> You do make a point about the changes.  It seems that most of the 
> lockups are when I make quick changes to the applications.
> 
> Any hints on what to look for via strace or what application to look at?
> 

I think I found the problem as last night I did everything that was hard 
locking the system and it ran like a charm.

This may be useful to others.

It turned out to be a memory issue.  Changing a module (maybe just the 
seating) was enough.

Now to give the Linux kernel credit.

I don't know if there are ways that the kernel handles memory issues but 
I noticed last night that my loads were lower than before I found the 
problem.  They were at least 30% lower than before changing the memory 
module.

My system stopped and wouldn't reboot.  I started by suspecting a power 
supply again but all voltages were correct.  I tried to boot off a DVD 
and that worked.  I used a Ubuntu disk because my Fedora 10 disk was 
given to someone to use.  I couldn't boot into Ubuntu, just the 
installation menu.

There was a memtest selection so I decided to run it.  About 20 minutes 
in, the memtest froze.  I started it again from a reboot.  It again 
froze at around the 20 minute mark.  I made a note of the test (5) and 
then rebooted and ran the test.  I skipped the first 4 tests and started 
test 5.  Froze in seconds.

I pulled out the one module (an old module that has been in the computer 
since purchase) and ran the memtest.  It made it to test 6 so I put in a 
different module and started the test again.  It passed.

Talking with one of our techs today, it was interesting in the fact that 
the system would run very well and only seemed to freeze if I ran videos 
in vlc or xine.

I say that this is a good indication of the stability of the kernel 
where it seems to be able to work around some memory issues.



-- 
Robin Laing