[lug] sluggish machine

Thu Jun 4 15:58:28 MDT 2009

We had similar issues with two machines of ours-
we opened them up and each had a row of blown capacitors on the mother 
board.

++++++++++++++++++++++++++++++++++++++++++++++++++++++
David R. Novotny
National Institute of Standards and Technology
Electromagnetics Division 
RF Fields Group
M/S 818.02                   Phone: (303) 497-3168  
325 Broadway                FAX:   (303) 497-7534
Boulder, CO 80305-3328      email: novotny at boulder.nist.gov

http://www.boulder.nist.gov/div818/81802/

The world is full of givers and takers - 
  The takers eat better; but, the givers sleep better.

    --- Excerpt from a Chinese Fortune Cookie

Any opinions or statements, faulty as they probably are, 
are mine(usually) and do not reflect anyone else's 
(especially my employer's).
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 

Davide Del Vento wrote:
> I (involuntarily) trigger it again.
>
> The fact:
> CPU temperature was 81 degrees (Celsius)
> CPU speed was 800MHz (and not speeding up while the system was sluggish)
> /var/log/messages did not report anything
> Xorg and firefox were the more than 90% CPU users (maybe I am hitting
> the bug mentioned by Lee?)
> NoScript was ON, but many (corporate, maybe heavy but hopefully not
> rogue) websites were allowed
> Probably a certain action on (corporate) MeetingMaker was trigging it,
> but I was not able to reproduce it (when I try, the CPUs scale up to
> 1.2GHz, but the temperature now is about 75 degrees)
>
> Any other suggestions?
>
> Thanks,
> ;Dav
>
> On Thu, May 21, 2009 at 16:48, Davide Del Vento
> <davide.del.vento at gmail.com> wrote:
>   
>> Thanks everybody for the help.
>> I'm replying to everything in just a consolidated email.
>>
>>     
>>> 1. RAM usage (is it swapping like mad?)
>>>       
>> No, or better, I know how it sounds and I'm not complaining when it is
>> happening (after all if I need more than 2GB from a laptop I cannot
>> complain... In these cases I should use the 128GB per node we have in
>> bluefire, not the laptop...)
>>
>>     
>>> 2. I'd wonder about a failing hard drive
>>> (anything in /var/log/messages that looks suspicious?)
>>>       
>> No, but I could be overlooking something. Any keyword to grep?
>>
>>     
>>> Next I'd grab a CD with memtest86 on it (CentOS install CD, for example
>>> has it... you just type memtest86 at the CD boot prompt)
>>>       
>> Tried my ubuntu memtest86 availabe on the hard drive (this machine
>> doesn't have any CD reader)
>> I tried it a few times in the past, but never for so long. It took 14
>> hours to arrive at the 6th test (of 10), with 48% of test successfully
>> passed and no errors, so far. Notable data: 2038MB of memory, going at
>> 1.8GB/s and ECC is off (I noted the whole page, but I'm not retyping
>> it here, should I?)
>>
>>     
>>> Sounds more like a heat issue.  Check that the fan is running and that
>>> the machine isn't hot to the touch.  Throttling the cpu is one way the
>>> machine tries to protect itself.
>>>       
>> The fan sounds ok, but the heat sink might have been detached or
>> something (it's a laptop, vibrations are always an issue....)
>> After your advice, I installed the CPU-frequency-scaling and Sensors
>> applet. I'm running 70-80 degrees (Celsius), since I installed the
>> temperature monitor, but the laptop is colder than the maximum
>> skin-feeling I remember.
>>
>> I did my homework to know what's the normal temperature for my U7600
>> and I found what follows:
>>
>> http://download.intel.com/design/mobile/datashts/31674505.pdf (pag 79)
>> indicates a 100 degree Celsium maximum operating temperature (of the
>> chip, non of the case neither of the air). The shut-down temperature
>> is 125 degrees (many other pages in the same PDF).
>> Same numbers in this unofficial, but better readable table:
>> http://www.cpu-world.com/CPUs/Core_2/Intel-Core 2 Duo Mobile U7600
>> LE80537UE0092M.html
>>
>> So currently I'm running 20 degrees (40 F) lower than the maximum. The
>> skin feeling I remember didn't was this hotter, but....
>>
>> ... so far I noticed that the CPU-frequency sometimes doesn't scale up
>> quickly, and I get a little slower performance (nothing, compared to
>> what I was telling in my previous email, but a clue): sometimes it
>> sticks at 800MHz instead of scaling up to 1.2GHz.
>>
>>     
>>> One way to isolate the problem to the web is to just close firefox and
>>> see if the problem goes away.
>>>       
>> I'd already tried this BEFORE you suggested, and this is what I found.
>> I didn't have any chance to re-try it later (with the above-mentioned
>> applets) because it didn't happen again.
>> Anyway, when I closed firefox (very difficult, I had to kill it on a
>> non-responsive system), the machine recovered, but not quickly enough.
>> I mean, after you free ~200MB RAM and ~ 50% CPU usage, the system is
>> clearly more responsive, but still slugglish. Only after lot of time
>> it went back to "like new" (I didn't reboot just after because I had
>> many ssh sessions open that I didn't want to lose).
>>
>>     
>>> You can also try to enable NoScript for firefox and see if that catches
>>> which page is doing evil things, if any.
>>>       
>> This is a wonderful tool! I didn't know about it. Thanks for
>> suggesting, I'll keep it always running now. I need to enable almost
>> all of the websites I use, but I'm blocking everything I google and
>> everything I don't explicitly need, great! I highly recommend it to
>> everybody, even if currently you don't have any problem!
>>
>>     
>>> i'd bet you 100% it's your browser, especially if you tab browse a lot and
>>> leave the browser running all day long.
>>>       
>> I often do. But as I wrote, it didn't seem to be the whole story. Indeed....
>>
>>     
>>> as someone else suggested, just kill the browser.  that'll be a quick test
>>> if you're performance comes back.
>>>       
>> ... the performance didn't come back right after.
>>
>> So far, I think what was happening is the follows:
>>
>> a) the CPU was slightly overheat (possibly triggered by that heavy
>> python script I mentioned)
>> b) the CPU-frequency downscaled (maybe due to a? I have to do some
>> homework on that and see how does it work)
>> c) something in firefox was eating more than 50% CPU-time and lot of memory
>> d) the rest of the apps eating the rest of the resources
>> e) maybe I had also bad memory fragmentation, possibly caused by
>> firefox and the python script
>>
>> c (and maybe also d) were aggravating a
>>
>> This would explain the observed behavior (including the slow "healing"
>> after killing firefox, due to cooling down, that is surely much slower
>> than freeing memory).
>> I will try to trigger it again, leaving firefox on for a day with a
>> lot of possible "evil" tabs and NoScript disabled. Then I'll run the
>> heavy python script. If I will reproduce the heavy slow-down, the
>> CPU-frequency and temperature applet will give me more info than just
>> the system monitor applet saying 100% CPU-usage (this will happen at
>> the beginning of June, until then I really will not have time to
>> play...)
>>
>> Currently, I'm loving NoScript and I'm avoid the python script (even
>> if I need it, but I need other things most), so this might explain why
>> it's not happening.
>>
>> I will only need to figure out if there is a "trivial" hw problem such
>> a wobble heat sink. I'll keep you posted!
>>
>> Thanks again everybody and let me know if you have any additional idea!
>> ;Dav
>>
>> On Tue, 19 May 2009 16:09:56 -0600, "Davide Del Vento"
>> <davide.del.vento at gmail.com> said:
>>     
>>> Folks,
>>> I'm having a weird problem. My laptop is slowing down often, up to a
>>> point where it becomes unusable. Then it return faster as it was, or
>>> sometimes (like when I wrote the first draft of this email) still very
>>> slow, but usable - I am typing about two words forward the ones it is
>>> showing on the screen.
>>>
>>> *********************
>>> The facts:
>>> The machine becomes incredibly slow, system monitor reports 100% CPU
>>> usage, and many windows (most notably firefox) become irresponsive and
>>> grayed-out.
>>>
>>> *********************
>>> The clues:
>>> System monitor (as well as top) does not report a single process that
>>> is hogging all the resources, but it might not able to refresh often
>>> enough. The top-six for memory and CPU are firefox, xorg, evolution,
>>> thunderbird, system monitor itself and (oddly?) geyes. The rest are in
>>> the single digit (or even 0.something) range.
>>>
>>> The obvious suspects are javascript in the large number of pages I
>>> keep active in firefox (I need them, don't suggest to not use them,
>>> they are almost all work related, besides gmail for chatting with
>>> family and friends - maybe chrome would have been better to pinpoint
>>> the guilty site, but we don't have it for linux)
>>> On a similar system (older hw, same OS, maybe slightly different
>>> packets installed - oddly less carefully picked, like skype) they the
>>> same websites don't create this mess! So it's not (entirely) web's
>>> fault.
>>>
>>> I did deleted my .mozilla directory and let firefox re-create it
>>> again. Painful (autocompletion, history, settings lost, etc) and
>>> useless: the problem si exactly the same. I unistalled  firebug (but
>>> it was disabled...), I uninstalled completely firefox-3.0 and all
>>> related packages (gnome-support, ubufox, etc), did apt-get autoclean
>>> and autoremove. After reinstalling (firebug excluded) the problem is
>>> still here (less frequent, maybe...)
>>>
>>> RootKit might be a possibility, but nmap didn't find anything, and
>>> rkhunter, unhide and chkrootkit didn't find anything "too strange"
>>> (well, it did find something, but many people online say that are
>>> false positive - or are they the RootKit authors? - and then a true
>>> positive might hide in the list). And I trust more nmap than
>>> rkhunter, unhide and chkrootkit.
>>>
>>> Fragmentation may contribute to the issue, since everything started
>>> when I had to create a couple of multi-gigabyte files (suddenly
>>> raising my / usage from ~30% to ~70%) and I had to read these files
>>> with my own python scripts to do some data-analysis. During that time
>>> the system was REALLY sluggish and started to swap, but at the end the
>>> process was successful. But fragmentation does not explain the 100%
>>> CPU usage (which files should I check with filefrag -v?)
>>>
>>> *********************
>>> The system:
>>> Ubuntu Hardy 8.04.2 - fully kept updated
>>> Linux-2.6.24-24-generic  i686
>>> Gnome 2.22.3
>>>
>>> Dell Dual Core U7600 @ 1.2GHz
>>> 2GiB RAM
>>>
>>> Usually used with Dell dock-station and external keyboard, mouse and
>>> monitor.
>>>
>>> *********************
>>>
>>> Do you have any suggestion? Even if not, thanks for reading this long
>>> message.
>>>
>>> Bye,
>>> ;Dav
>>>       
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