Re: kapm-idled shows 90+% cpu usage when idle

safemode (safemode@speakeasy.net)
Thu, 9 Aug 2001 22:01:55 -0400


On Thursday 09 August 2001 20:36, Mikael Pettersson wrote:
> On Thu, 9 Aug 2001 19:33:42 -0400, safemode <safemode@speakeasy.net> wrote:
> >Is this a true usage reading or just some quirk that's supposed to happen?
> >I really doubt that this kernel daemon should really be using cpu. It
> > seems to respond with a higher cpu usage when i'm idle. It immediately
> > goes away when something else uses cpu. If you need any more info just
> > ask. I'm
>
> Do you have CONFIG_APM_CPU_IDLE=y in your .config? If so, disable it.
>
> There was a thread about this problem some months ago. I found
> that on all of my APM-capable machines, including a Dell laptop,
> CONFIG_APM_CPU_IDLE=y had a negative effect. The kernel ended up
> in a tight loop performing tons of APM IDLE BIOS calls, since each
> BIOS call returned immediately without having idled the CPU.
>
> Leaving CONFIG_APM_CPU_IDLE unset lets the kernel use its own
> "HLT when idle" code. On my main development box, idle CPU
> temperature dropped >10 degrees C, and kapm-idled now uses 0% CPU.
>
> /Mikael

I've been told by others that this is exactly what's supposed to happen. It
acts like it's using cpu when it's idle and does it job that way. I see no
difference either way. I'm using a KA7 motherboard and it says it supports
apm and lspci shows what i pasted in the original post. Oh well, it's not
causing the cpu to generate more heat than it would be idle.
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