Re: High load average (~2.0) on an idle PowerPC 64 machine
On Thu, 2011-03-24 at 21:23 +0100, Romain Goyet wrote: I there, I've this Quad G5 machine that's sitting pretty much idle with the latest Debian stable installed, and yet it's got an abnormaly high load average. I've detailed the situation over here, maybe you guys will find it interesting or have something to say : http://serverfault.com/questions/251299/high-load-average-over-2-0-on-an-idle-machine The machine doesn't seem to be actually slowed down, it looks more like an incorrect measurement. Thank you very much for any help ! From memory, this can be due to the thermal control driver's kernel thread, which essentially does uninterruptible sleeps all the time, either when waiting for request completion from SMU or i2c. Since it's pretty much constantly talking to these, it causes an increase load (they can take time to respond). So in effect it's not actually hogging the CPU. I don't know if there's a clean way to fix that. Now it's possible that there's a different cause, that's just talking from some vague memories, so some investigations would be useful regardless. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
High load average (~2.0) on an idle PowerPC 64 machine
I've this Quad G5 machine that's sitting pretty much idle with the latest Debian stable installed, and yet it's got an abnormaly high load average. The 'load average' value is rather useless since it seems to contain any process that is sleeping uninterruptibly, and IIRC any process that has run at all (for however short a period) in the current schedule epoch (or whatever period is relevant). I can easily generate a linux system that is 99.9% idle but has a 'load average' of 20 or more. It would still be 99.9% idle even if the idle time were based of the actual time outside the scheduler idle loop (as NetBSD doe) rather than where timer ticks interrupted. We also have the related fubar (on x64/amd64) of the kernel generating stack traces for processes that are sleeping uninterruptibly for long periods. David ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: High load average (~2.0) on an idle PowerPC 64 machine
On Fri, 2011-03-25 at 09:23 +, David Laight wrote: We also have the related fubar (on x64/amd64) of the kernel generating stack traces for processes that are sleeping uninterruptibly for long periods. Turn off CONFIG_DETECT_HUNG_TASK? ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
High load average (~2.0) on an idle PowerPC 64 machine
I there, I've this Quad G5 machine that's sitting pretty much idle with the latest Debian stable installed, and yet it's got an abnormaly high load average. I've detailed the situation over here, maybe you guys will find it interesting or have something to say : http://serverfault.com/questions/251299/high-load-average-over-2-0-on-an-idle-machine The machine doesn't seem to be actually slowed down, it looks more like an incorrect measurement. Thank you very much for any help ! - Romain ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
