Re: idle Athlon with IOAPIC is 10C warmer since 2.6.3-bk1

[Prakash K. Cheemplavam]

> OK, now I had the time to test if different C states are working with
> following three kernels:
>
> 1. 2.6.4-mm2 without the 8259-timer-ack-fix.patch and without the 
C1halt idle
> function.
> 2. 2.6.4-mm2 with the 8259-timer-ack-fix.patch and without the C1 
halt idle
> function enabled.
> 3. 2.6.4-mm2 with the 8259-timer-ack-fix.patch and with the C1 halt idle
> function enabled.
>
> I used following script to print the C-state counters on an complete 
idle
> machine before and after a 10second interval:
>
> # /bin/sh
> cat /proc/acpi/processor/CPU0/power
> sleep 10
> cat /proc/acpi/processor/CPU0/power
>
> Now the results:

[snip]

> 3.:
> active state:            C1
> default state:           C1
> bus master activity:     00000000
> states:
>    *C1:                  promotion[C2] demotion[--] latency[000] 
> usage[00000000]
>     C2:                  promotion[--] demotion[C1] latency[100] 
> usage[00000000]
>     C3:                  <not supported>
> active state:            C1
> default state:           C1
> bus master activity:     00000000
> states:
>    *C1:                  promotion[C2] demotion[--] latency[000] 
> usage[00000000]
>     C2:                  promotion[--] demotion[C1] latency[100] 
> usage[00000000]
>     C3:                  <not supported>
>
> So, as you can see, the C1halt patch does not help here... ;-(

Hmm, I just did a cat /proc/acpi/processor/CPU0/power:
active state:            C1
default state:           C1
bus master activity:     00000000
states:
   *C1:                  promotion[--] demotion[--] latency[000] 
usage[00000000]
    C2:                  <not supported>
    C3:                  <not supported>

I am currently NOT using APIC mode (nforce2, as well) and using vanilla 
2.6.4. It seems C1 halt state isn't used, which exlains why I am having 
trouble to keep my CPU cooler these day. I once started a thread 
suspecting acpi timer, but it is not the case. It seems to be something 
else. As I don't use PIC, it cannot be that  8259-timer-ack-fix.patch 
causin git, or can it? Maybe something broken in ACPI? I might try out 
older kernels to find out...

Prakash
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