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

From: Thomas Schlichter (thomas.schlichter_at_web.de)
Date: 03/19/04

  • Next message: Jesse Barnes: "Re: Exporting physical topology information" 
    To: ross@datscreative.com.au
Date:	Fri, 19 Mar 2004 19:55:36 +0100

    Am Donnerstag, 18. März 2004 01:19 schrieb Ross Dickson:

    ~~ snip ~~

    > > The only way to cool down my CPU was to enable timer_ack.
    > > I don't know how to help you, but of course I am willing to test
    > > patches... ;-) Thomas
    >
    > I agree with Len Brown's comments to try to examine which power saving
    > state but if you want to try to brute force C1 state ( only works if
    > chipset supported ) you could try this patch for process.c,
    > (ignore the io-apic patch as it is nforce2 specific).
    >
    > http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-02/6520.html
    > The KERNEL ARG to invoke it is "idle=C1halt".
    >
    > It has an extra function pointer to prevent the power management idle
    > routine hikjacking things after the command line arg has requested an idle
    > routine.
    >
    > These idle mods appear to assist more than just nforce2 Athlon boards.
    > Thomas Herrmann has had success with an SIS740
    >
    > > Hi Ross,
    > > I just want to let you know that your nforce2_idle patch does work with
    > > the SiS740 chipset too. While the current ACPI patch already routes the
    > > timer of the SiS740 to IO-APIC-edge with out the C1halt option of your
    > > nforce2_idle patch the system locked up when STPGNT was enabled. But
    > > after I applied your nforce2_idle patch to kernel 2.4.24 together with
    > > the C1halt kernel boot option, the system runs stable for hours.
    > > Great work, thanks!
    > > Best regards, Thomas
    >
    > Craig Bradney has put it into the gentoo dev sources also.
    > http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-03/1746.html

    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:

    1.:
    active state: C2
    default state: C1
    bus master activity: 00000000
    states:
        C1: promotion[C2] demotion[--] latency[000]
    usage[00006280]
       *C2: promotion[--] demotion[C1] latency[100]
    usage[00300041]
        C3: <not supported>
    active state: C2
    default state: C1
    bus master activity: 00000000
    states:
        C1: promotion[C2] demotion[--] latency[000]
    usage[00006300]
       *C2: promotion[--] demotion[C1] latency[100]
    usage[00310045]
        C3: <not supported>

    2.:
    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>

    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... ;-(

    Regards
       Thomas Schlichter

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