Ed Sweetman wrote:
> System is idle now, previously it was doing something i couldn't halt at
> the time. I'm looking at "Local timer interrupts" in the "Loc:" section
> of /proc/interrupts.
> Across 1 second while the system is pretty much idle, i still get 300
> interrupts. My HZ variable is set to 300 in the kernel config, so this
> is expected but I was under the assumption that dynticks/tickless being
> compiled in would cause that to be much lower.
>
> Am I reading the wrong section of /proc/interrupts to verify if
> dynticks is working or not? Again, i see no difference in cpu temp at all.
Try running powertop ( http://www.lesswatts.org/projects/powertop/ ) and
see what it reports.
I don't think dynticks will generally save huge amounts of power on a
typical desktop machine. The big gains come from being able to stay in
deep sleep C-states (C2/C3) for longer periods of time, but most desktop
machines only enable sleep states down to C1.
>
> In case it helps, this is an athlon64 x2 with apic functioning and both
> cores active in 64bit mode. dmesg is below.
> not related :
> Some additional notes: it87 is my lm_sensor, it doesn't work in this
> kernel, yet it did in 2.6.22. Perhaps enabling high precision timers
> changed something in acpi land.
>
> I enabled tcp dma offloading in this kernel, i get debugging output
> related to it, error is at the last line. No corruption or otherwise
> bad behavior. Transferring via cifs at 9.7MB/sec "incoming" took about
> 15% of one cpu... I never bothered to check if that is the norm but i
> suspect i'll be removing that feature as it seems to not play nice with
> the kernel.
--
Robert Hancock Saskatoon, SK, Canada
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Home Page: http://www.roberthancock.com/
Robert Hancock wrote:
> Ed Sweetman wrote:
>> System is idle now, previously it was doing something i couldn't halt
>> at the time. I'm looking at "Local timer interrupts" in the "Loc:"
>> section of /proc/interrupts.
>> Across 1 second while the system is pretty much idle, i still get 300
>> interrupts. My HZ variable is set to 300 in the kernel config, so
>> this is expected but I was under the assumption that
>> dynticks/tickless being compiled in would cause that to be much lower.
>>
>> Am I reading the wrong section of /proc/interrupts to verify if
>> dynticks is working or not? Again, i see no difference in cpu temp at
>> all.
>
> Try running powertop ( http://www.lesswatts.org/projects/powertop/ )
> and see what it reports.
>
> I don't think dynticks will generally save huge amounts of power on a
> typical desktop machine. The big gains come from being able to stay in
> deep sleep C-states (C2/C3) for longer periods of time, but most
> desktop machines only enable sleep states down to C1.
>
I tried running powertop, it complains about not having timer
statistics, I looked throughout the kernel config for a timer stat
option, but can't find one.
I didn't have hpet compiled in, i'm not sure if this is required but a
lot of places seem to suggest hpet and high precision timer and tickless
be compiled together. I also disabled cpuidle and i'll reboot and try
that.
>>
>> In case it helps, this is an athlon64 x2 with apic functioning and
>> both cores active in 64bit mode. dmesg is below.
>> not related :
>> Some additional notes: it87 is my lm_sensor, it doesn't work in this
>> kernel, yet it did in 2.6.22. Perhaps enabling high precision timers
>> changed something in acpi land.
>>
>> I enabled tcp dma offloading in this kernel, i get debugging output
>> related to it, error is at the last line. No corruption or otherwise
>> bad behavior. Transferring via cifs at 9.7MB/sec "incoming" took
>> about 15% of one cpu... I never bothered to check if that is the
>> norm but i suspect i'll be removing that feature as it seems to not
>> play nice with the kernel.
>
Ed Sweetman wrote:
> Robert Hancock wrote:
>> Ed Sweetman wrote:
>>> System is idle now, previously it was doing something i couldn't
>>> halt at the time. I'm looking at "Local timer interrupts" in the
>>> "Loc:" section of /proc/interrupts.
>>> Across 1 second while the system is pretty much idle, i still get
>>> 300 interrupts. My HZ variable is set to 300 in the kernel config,
>>> so this is expected but I was under the assumption that
>>> dynticks/tickless being compiled in would cause that to be much lower.
>>>
>>> Am I reading the wrong section of /proc/interrupts to verify if
>>> dynticks is working or not? Again, i see no difference in cpu temp
>>> at all.
>>
>> Try running powertop ( http://www.lesswatts.org/projects/powertop/ )
>> and see what it reports.
>>
>> I don't think dynticks will generally save huge amounts of power on a
>> typical desktop machine. The big gains come from being able to stay
>> in deep sleep C-states (C2/C3) for longer periods of time, but most
>> desktop machines only enable sleep states down to C1.
>>
> I tried running powertop, it complains about not having timer
> statistics, I looked throughout the kernel config for a timer stat
> option, but can't find one.
>
> I didn't have hpet compiled in, i'm not sure if this is required but a
> lot of places seem to suggest hpet and high precision timer and
> tickless be compiled together. I also disabled cpuidle and i'll
> reboot and try that.
>
read too fast through the powertop error message. timer stat info is in
kernel_debug option. Which i did not compile in this latest kernel
again. Sorry.
Though, with hpet and such, i still see no measurable difference or any
sort of evidence that ticks are being skipped (comparing
/proc/interrupts across sleep 1s;)
>
>>>
>>> In case it helps, this is an athlon64 x2 with apic functioning and
>>> both cores active in 64bit mode. dmesg is below.
>>> not related :
>>> Some additional notes: it87 is my lm_sensor, it doesn't work in
>>> this kernel, yet it did in 2.6.22. Perhaps enabling high precision
>>> timers changed something in acpi land.
>>>
>>> I enabled tcp dma offloading in this kernel, i get debugging output
>>> related to it, error is at the last line. No corruption or
>>> otherwise bad behavior. Transferring via cifs at 9.7MB/sec
>>> "incoming" took about 15% of one cpu... I never bothered to check
>>> if that is the norm but i suspect i'll be removing that feature as
>>> it seems to not play nice with the kernel.
>>
>