[TAG] using smp kernel, get 100% cpu usage one one cpu without any real load on the system

[Marty Leisner]

jim ruxton <cinetron at passport.ca> writes  on Mon, 08 Oct 2007 14:21:21 EDT
     > Hi I'm on a P4 running an smp kernel ie.
     > 
     > uname -a :
     >  
     > Linux jims-laptop 2.6.20-16-386 #2 Sun Sep 23 19:47:10 UTC 2007 i686
     > GNU/Linux
     > 
     > For some reason occasionaly one of my cpu's runs away and starts showing
     > 100% cpu usage, however top only shows the program using the most cpu at
     > 7% or less. Where is that 93% going? This is driving me crazy. I have to
     > reboot the machine to get it back to normal. I've tried Fedora and
     > Kubuntu. Though Kubuntu appeared more stable it still happened. Played
     > around with changing max_cstate without success.I've just downgraded to
     > a 386 kernel to see if that helps. This isn't a real solution however.
     > Do you have any suggestions? I've asked around on forums and irc
     > channels without luck. Thanks.
     > Jim
     > 
     > 
     > output of cat /proc/cpuinfo :
     > 

top also reports kernel, idle, user  and a few others...

Are you 100% user?  Is the system sluggish?

What type of load average are you seeing?

Also, if you're SMP there's an option in top to display each CPU (in recent procps tops, type 1).

[tops a lovely program -- there's been so many flavors since Bill Lefebvre version -- all slightly different...

Have you also run other load monitors as a sanity check?

marty