[SOLVED] Very slow system response to user input, variable (and HIGH) CPU load on P4 HT system

f4c3l355 · 09-18-2009, 09:13 AM

On a Gentoo Base System release 1.12.11.1 distro and a system with P4 HT (Hyper-Threading) processor I have the following problem:
Approximately half an hour after boot, the system becomes very non-responsive, for example scrolling in a window is very slow, with delays, response to keyboard input is also very slow etc. In system monitor the graph which shows the two core's load I have the following: when one core runs on 100%, the other is running on approx. 70-80%, and then the loads switch between them, the first core runs on 70-80% and the second on 100%. Maybe this comes from the HT processors arhitecture, I don't know, but I think it's a bit susspicious.
The overall feel of the system is like it's like on a Pentium I class processor...
Here's a top output:

Code:

top - 16:50:54 up 7 days,  7:53,  6 users,  load average: 0.44, 0.37, 0.82
Tasks: 127 total,   2 running, 125 sleeping,   0 stopped,   0 zombie
Cpu0  : 21.5%us,  0.7%sy,  0.0%ni, 77.8%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu1  :  1.0%us,  0.3%sy,  0.0%ni, 98.7%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:   1032252k total,   767440k used,   264812k free,    65688k buffers
Swap:  2104376k total,     7872k used,  2096504k free,   419580k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                                                                                                         
10874 root      20   0  331m  52m  14m S   21  5.2  40:48.40 X                                                                                                                                                                               
11125 kalman    20   0 83964  33m  15m S    1  3.3   1:24.18 skype                                                                                                                                                                           
11120 kalman    20   0 55484  16m  10m R    1  1.7   0:07.37 gnome-terminal                                                                                                                                                                  
11121 kalman    20   0  213m  85m  27m S    1  8.5   9:43.63 firefox                                                                                                                                                                         
    1 root      20   0  1640  104   80 S    0  0.0   0:01.28 init                                                                                                                                                                            
    2 root      15  -5     0    0    0 S    0  0.0   0:00.00 kthreadd                                                                                                                                                                        
    3 root      RT  -5     0    0    0 S    0  0.0   0:00.86 migration/0                                                                                                                                                                     
    4 root      15  -5     0    0    0 S    0  0.0   0:00.01 ksoftirqd/0                                                                                                                                                                     
    5 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/0                                                                                                                                                                      
    6 root      RT  -5     0    0    0 S    0  0.0   0:01.21 migration/1                                                                                                                                                                     
    7 root      15  -5     0    0    0 S    0  0.0   0:00.03 ksoftirqd/1                                                                                                                                                                     
    8 root      RT  -5     0    0    0 S    0  0.0   0:00.00 watchdog/1                                                                                                                                                                      
    9 root      15  -5     0    0    0 S    0  0.0   0:03.37 events/0                                                                                                                                                                        
   10 root      15  -5     0    0    0 S    0  0.0   0:00.17 events/1                                                                                                                                                                        
   11 root      15  -5     0    0    0 S    0  0.0   0:00.00 work_on_cpu/0                                                                                                                                                                   
   12 root      15  -5     0    0    0 S    0  0.0   0:00.00 work_on_cpu/1                                                                                                                                                                   
   13 root      15  -5     0    0    0 S    0  0.0   0:00.02 khelper                                                                                                                                                                         
  162 root      15  -5     0    0    0 S    0  0.0   0:00.26 kblockd/0                                                                                                                                                                       
  163 root      15  -5     0    0    0 S    0  0.0   0:00.13 kblockd/1                                                                                                                                                                       
  165 root      15  -5     0    0    0 S    0  0.0   0:00.00 kacpid                                                                                                                                                                          
  166 root      15  -5     0    0    0 S    0  0.0   0:00.00 kacpi_notify

etc.

If anybody had same experiences and/or knows the cause/solution to this, please reply.
Thanks.

syg00 · 09-19-2009, 08:40 PM

Gentoo used to run fine on my P4 H/T box - haven't tried it in a while though. These days I would think hiperthreading is unlikely to be a problem in itself.
For help, you are going to need to supply info during a bad period - that top output doesn't show anything particularly unusual.

f4c3l355 · 09-21-2009, 01:17 AM

Well, it ran very fine until a few days ago, when it started to go very slow... If you could tell me what information should I supply aside top (because that's the top during a bad period)?
Could this be some X related (or graphics card/driver) issue?
Could this be due to some files beeing deleted by mistake? (This is my system at work, and maybe some other users logged on while I wasn't there... and yes, I told to the system admins about these problems, but they just said: we'll look at it sometime... and I'm left with a machine that is barely usable).
Also, we use a program called grinder that does some distributed work on the firm's machines while we aren't at work, like from 8:00 PM till 8:00 AM, maybe the scheduling for grinder was messed up... ps aux | grep grinder returns the following row:

kalman 725 0.0 0.0 1872 524 pts/0 S+ 09:11 0:00 grep , but the stat column for this process says S+ which means sleep, so this shouldn't use that much CPU.

That's all the info I could gather for now...

f4c3l355 · 09-23-2009, 08:28 AM

I think I have the answer: I switched to another window manager (XFCE) and the problem disappeared... I'll see in the next days if this really solves the problems...
I've read somewhere on google that Gnome window manager (that I was using) is a bit buggy, maybe some bug caused my problems...

Thanks anyway