1 2 Previous Next 16 Replies Latest reply: Nov 28, 2012 9:23 PM by OYGVALT
WZZZ Level 6 Level 6 (12,225 points)
I have iStat Menus in the MenuBar so I'm able to see when the CPU usage finally drops after finishing everything the G3 needs to do after bootup and log in.

It may have always been like this, and I'm only noticing it now and bothered by it because I've gotten used to a speedy "modern" computer, but I'm seeing the system busy reading the kext.cache at between 60% and 80% of CPU for as long as a minute and a half. It's taking that long before the CPU usage finally drops down and the system is free for other tasks. I've tried cleaning all the caches with Applejack, and there have been enough restarts since doing so that all the caches would be rebuilt by now. The time loading and reading the kext.cache has not improved. RAM is 768 MB.

Just wondering if anyone with a comparably slow G3 can see how long this is taking on theirs. (rc charles with a bit faster 600 maybe?)

iMac 21.5" 10.6.5, iMac G3/400 10.4.11
  • 1. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    EDIT: just to be clear, CPU usage is at or near 100% for a full minute and a half after log in. It varies, but the kext.cache is responsible for between 60%-80% of that.
  • 2. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    What's kext.chache? Something to do with kernel extensions? How did you detect?

    I created a new admin user. I installed istatmenu 1.3 on this id. I set the new id as autologon.

    It took 1'15" to get to the istatmenu. I saw a mountain like image for the cpu usage. After which, Cpu usage went to nothing. Just occasional periods appearing.

    My normal logon id takes several more minutes to startup since I have several login items.

    Robert
  • 3. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Actually, it's kextcache, not kext.cache (my mistake.) If you click on iStat Menus, it will show, in a llittle dropdown, the four or five most CPU consuming processes. I do not have auto login set. I'm seeing the CPU monitor in iStat Menus just after login. The bootup itself takes maybe a minute; will have to test that when I'm back on the G3.

    Thanks for trying this out.
  • 4. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    why don't you create a new admin user & try istatmenu to see how fast or slow istatmenu runs.

    create id. install istatmen on id. restart machine. login to new id.

    ------

    Did notice that some other people where having problems with kextchache
    did a google search on
    kextchache

    Robert

    Message was edited by: rccharles
  • 5. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Thanks Robert, I'll try it in my test account at some point, but I think I'll probably find the same behavior; it's just a slow machine.
  • 6. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    Thanks for the star.

    ---------

    It's a slow machine, but I think kextchache is misconfiguration or something. I read where people run kextchache manually in earlier releases of X, but this is no longer needed in Tiger. ( a somewhat vague memory. )

    If it works, might not be a big deal.

    Robert
  • 7. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Interesting. You don't have it on your 10.4.11? I've already run Applejack in deep cleaning mode a while ago, which would have removed it. Guess it got rebuilt, which makes me think it belongs there, or something....

    I have a kextcache in /usr/bin on this 10.6. Seems like it would be a fairly standard cache in any OS X.

    Or maybe I misunderstand what you mean, "kextcache is misconfiguration or something...."
  • 8. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    In 10.4.11, I have:
    /usr/sbin/kextcache

    Macintosh-HD -> Applications -> Utilities -> Terminal
    man kextcache


    I do not know much about kextcache. I was saying people were running kextcache from the command line to improve performance. In 10.4.11, you do not need to run manually.

    You do not have some login item or some haxie ( system preference )?

    Could be all wrong for what I know. Just guessing here.

    Robert

    Message was edited by: rccharles
  • 9. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    From man kextcache

    The kextcache program creates kext caches, which speed up kext loading
    operations. It is invoked automatically as needed to rebuild system
    caches.


    I didn't realize until now that was its function. I mistakenly thought the activity I was seeing was the kext caches being read and loaded. So the question is why would kextcache be running, apparently, each time I boot up? What's happening to those caches that they need to be constantly rebuilt? That's what I need to find out.
  • 10. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Coming up completely empty handed on this one. Booting in Verbose Mode always shows "0 cached 330 uncached personalities to catalog" and "Resetting IO Catalog."

    Something is making kextcache think it has to rebuild all the kext caches on each reboot. I've seen threads where kextcache is crashing, but that's not the case here. Each rebuild is apparently successful; I see it finishing. But then it has to do it all over again the next time.

    Searching, I don't find anyone with this same problem.
  • 11. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    Perhaps it is finishing in failure. Have you checked the console logs? Maybe you could run it manually. It should be documented since people were running it manually in the past. perhaps running manually with the right options would flip some bit somewhere.

    Does it occur after boot or when you login? Tired a second id? Does delaying login for 15 mins make a difference?

    Robert
  • 12. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Nothing in the system log to show failure or success. Might try running it manually -- will need to find just what that command should be -- to give it a kick in the pants. I did notice that if I waited a few minutes before logging in, it seemed to have finished. So, it doesn't seem connected to the log in. Just reapplied the 10.4.11 Combo. Restarted twice and kept seeing it hogging the CPU, as usual.

    Since I now know if I wait a bit, it's running, peaking and clearing up before log in, I think the account is probably irrelevant.

    You don't see any sign of kextcache in AM or iStat Menus when you bootup?

    Thanks for your help and ideas.
  • 13. Re: System is slow loading/reading kext.cache after boot up
    rccharles Level 5 Level 5 (5,370 points)
    You don't see any sign of kextcache in AM or iStat Menus when you bootup?


    I wouldn't know. I run several login scripts. Takes fivish minutes to boot to working system. I don't hang around.


    Interesting article. Could be one of your extension is getting a date change & thus causing the invocation of kextcache. Commands are listed too.
    http://reviews.cnet.com/8301-13727_7-20025628-263.html

    Robert
  • 14. Re: System is slow loading/reading kext.cache after boot up
    WZZZ Level 6 Level 6 (12,225 points)
    Thanks. Those commands are apparently not for Tiger (Terminal reports illegal option or instruction.) The Permissions he recommends setting are wrong for Tiger -- should be owner:system, group:wheel. Did run touch on the Extensions folder, which should have forced a rebuild, but I'm not seeing any change. I think I'm facing an A&I or I just forget about it.
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