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OT: thermal management diff 2.4 vs. 2.6

 

 

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ali at geschmeidomatik

Jun 28, 2005, 9:25 AM

Post #1 of 12 (1341 views)
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OT: thermal management diff 2.4 vs. 2.6

Hi list,

since i dont't know where else to ask this question i figured i might as
well ask it here.
i'm running gentoo on my tibook 550 (powerbook3,3 that is in
kernelspeak) and noticed that with a 2.4 kernel as well as under macos
the fan hardly ever kicks in, even when the computer gets quite hot
while with the 2.6 kernel the fan wouldn't stop running.

while this aproach is probably bying me some more lifetime for my
computer, it is seriously annoying not to have at least an occasional
moment of silence when sitting in front of the box.

i already tried searching the kerneltree for suspicious expressions like
"fan.*control" and such but so far without success (meaning i found only
acpi-related stuff).

can someone please give me a hint where else to look or even where else
to ask this question? any help is appreciated!

thanks in advance and best regards,

alexander


bruda at cs

Jun 28, 2005, 9:45 AM

Post #2 of 12 (1299 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

At 18:25 +0200 on 2005-6-28 Alexander Meyer wrote:
>
> i'm running gentoo on my tibook 550 (powerbook3,3 that is in
> kernelspeak) and noticed that with a 2.4 kernel as well as under
> macos the fan hardly ever kicks in, even when the computer gets
> quite hot while with the 2.6 kernel the fan wouldn't stop running.

FWIW, I have noticed the same behaviour on a Tibook rev III
(PowerBook3,4), though the change in fan behaviour happened to me
between two 2.6 versions (not very sure which ones, but I am almost
sure that 2.6.7 was between the last kernels that made the fan shut up
from time to time).

By the way, I since upgraded the logic board and the machine has
become a rev IV. The fans (now two of them) seem to be on all the
time. This is not so much of a problem anymore since the fans are
much more silent than the original (sole) fan, but I am not sure
whether this is as it should be.

As far as I know the fans are hardware controlled on these models, so
the fans should not be affected by a kernel change... except that they
do just that. Must be grmelins in there or something.

Stefan

--
If it was so, it might be; and if it were so, it would be; but as
it isn't, it ain't. That's logic.
--Lewis Carroll, Through the Looking-Glass
--
gentoo-ppc-user [at] gentoo mailing list


colin at colino

Jun 28, 2005, 10:27 AM

Post #3 of 12 (1310 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On 28 Jun 2005 at 12h06, Stefan Bruda wrote:

Hi,

> As far as I know the fans are hardware controlled on these models, so
> the fans should not be affected by a kernel change... except that they
> do just that. Must be grmelins in there or something.

echo 10 > /sys/devices/temperatures/limit_adjust if you want the fans
to kick in at 60C instead of 50C.

--
Colin

--
gentoo-ppc-user [at] gentoo mailing list


bruda at cs

Jun 28, 2005, 10:49 AM

Post #4 of 12 (1294 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

At 19:27 +0200 on 2005-6-28 Colin Leroy wrote:
>
> > As far as I know the fans are hardware controlled on these models, so
> > the fans should not be affected by a kernel change... except that they
> > do just that. Must be grmelins in there or something.
>
> echo 10 > /sys/devices/temperatures/limit_adjust if you want the fans
> to kick in at 60C instead of 50C.

These are Tibooks (as opposed to newer Alubooks) so they do not have
software temperature control, no?

Stefan

--
If it was so, it might be; and if it were so, it would be; but as
it isn't, it ain't. That's logic.
--Lewis Carroll, Through the Looking-Glass

--
gentoo-ppc-user [at] gentoo mailing list


colin at colino

Jun 28, 2005, 12:03 PM

Post #5 of 12 (1306 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On 28 Jun 2005 at 13h06, Stefan Bruda wrote:

Hi,

> These are Tibooks (as opposed to newer Alubooks) so they do not have
> software temperature control, no?

mmh, I'm not sure right now. Try to load the therm_adt746x module. If it
fails to load, you're right :)

--
Colin
--
gentoo-ppc-user [at] gentoo mailing list


bruda at cs

Jun 28, 2005, 1:34 PM

Post #6 of 12 (1293 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

At 21:03 +0200 on 2005-6-28 Colin Leroy wrote:
>
> > These are Tibooks (as opposed to newer Alubooks) so they do not have
> > software temperature control, no?
>
> mmh, I'm not sure right now. Try to load the therm_adt746x module. If it
> fails to load, you're right :)

Oh, of course therm_adt746x won't load, sorry for not mentioning it.
There is as far as I know no option in the kernel config for thermal
management on these machines. I am clueless as to why is the fan
behaving differently, it simply shouldn't.

Stefan

--
If it was so, it might be; and if it were so, it would be; but as
it isn't, it ain't. That's logic.
--Lewis Carroll, Through the Looking-Glass
--
gentoo-ppc-user [at] gentoo mailing list


carl at hudkins

Jun 28, 2005, 4:22 PM

Post #7 of 12 (1297 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On Tue June 28 2005 16:34, Stefan Bruda wrote:

> Oh, of course therm_adt746x won't load, sorry for not mentioning it.
> There is as far as I know no option in the kernel config for thermal
> management on these machines. I am clueless as to why is the fan
> behaving differently, it simply shouldn't.

I'm not an expert here, but could it be the kernel is not using some kind of
CPU idling when it's not busy? Maybe the CPU is actually running hotter than
it used to. Just an idea, may not be founded in fact. ;)

--
// Carl Hudkins :: Jabber yther [at] amessage :: PGP 50238D9E
//
// ==] What would Jeeves do? [==
//
// (X-Spam-To: collapsar [at] yther)
--
gentoo-ppc-user [at] gentoo mailing list


ali at geschmeidomatik

Jun 29, 2005, 3:27 AM

Post #8 of 12 (1294 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On Di, Jun 28 2005 at 07:22:33 -0400, Carl Hudkins wrote:
> On Tue June 28 2005 16:34, Stefan Bruda wrote:
>
> > Oh, of course therm_adt746x won't load, sorry for not mentioning it.
> > There is as far as I know no option in the kernel config for thermal
> > management on these machines. I am clueless as to why is the fan
> > behaving differently, it simply shouldn't.
>
> I'm not an expert here, but could it be the kernel is not using some kind of
> CPU idling when it's not busy? Maybe the CPU is actually running hotter than
> it used to. Just an idea, may not be founded in fact. ;)
>

Well, if there's no means to control when the fan starts it probably
_is_ something like this. i'll try some earlier 2.6 kernels then since
Stefan earlier stated that this change didn't occur at the 2.4->2.6
switch but somewhere in the early 2.6 series (IIRC before 2.6.7).
i'm hardly using the machine anymore because that goddamn fan is just
too annoying and if i try to compensate by turning up my music the
neighbors will complain after a while ;(


colin at colino

Jun 29, 2005, 4:32 AM

Post #9 of 12 (1296 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On Wed, 29 Jun 2005 12:27:39 +0200
Alexander Meyer <ali [at] geschmeidomatik> wrote:

> Well, if there's no means to control when the fan starts it probably
> _is_ something like this. i'll try some earlier 2.6 kernels then since
> Stefan earlier stated that this change didn't occur at the 2.4->2.6
> switch but somewhere in the early 2.6 series (IIRC before 2.6.7).
> i'm hardly using the machine anymore because that goddamn fan is just
> too annoying and if i try to compensate by turning up my music the
> neighbors will complain after a while ;(

May be due to the defaut HZ value change.

--
Colin
--
gentoo-ppc-user [at] gentoo mailing list


ali at geschmeidomatik

Jun 29, 2005, 6:25 AM

Post #10 of 12 (1302 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On Mi, Jun 29 2005 at 01:32:29 +0200, Colin Leroy wrote:
> On Wed, 29 Jun 2005 12:27:39 +0200
> Alexander Meyer <ali [at] geschmeidomatik> wrote:
>
> > Well, if there's no means to control when the fan starts it probably
> > _is_ something like this. i'll try some earlier 2.6 kernels then since
> > Stefan earlier stated that this change didn't occur at the 2.4->2.6
> > switch but somewhere in the early 2.6 series (IIRC before 2.6.7).
> > i'm hardly using the machine anymore because that goddamn fan is just
> > too annoying and if i try to compensate by turning up my music the
> > neighbors will complain after a while ;(
>
> May be due to the defaut HZ value change.

Now _that_ is strange: I recently changed that back from 1000 to 100 but
with no visible (or audible that is) effect whatsoever.


gentoo at lakedaemon

Jun 29, 2005, 7:13 AM

Post #11 of 12 (1295 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

Alexander Meyer (ali [at] geschmeidomatik) scribbled:
> On Mi, Jun 29 2005 at 01:32:29 +0200, Colin Leroy wrote:
> > On Wed, 29 Jun 2005 12:27:39 +0200
> > Alexander Meyer <ali [at] geschmeidomatik> wrote:
> >
> > > Well, if there's no means to control when the fan starts it probably
> > > _is_ something like this. i'll try some earlier 2.6 kernels then since
> > > Stefan earlier stated that this change didn't occur at the 2.4->2.6
> > > switch but somewhere in the early 2.6 series (IIRC before 2.6.7).
> > > i'm hardly using the machine anymore because that goddamn fan is just
> > > too annoying and if i try to compensate by turning up my music the
> > > neighbors will complain after a while ;(
> >
> > May be due to the defaut HZ value change.
>
> Now _that_ is strange: I recently changed that back from 1000 to 100 but
> with no visible (or audible that is) effect whatsoever.
>

This is correct behavior. The value of HZ defines the minimum
resolution of system calls like usleep() and select(). At 100Hz, the
minimum resolution is ~20ms (= 2 * 1 / f) for usleep and ~10ms (= 1 / f)
for select(). Setting it to 1000Hz adjusts those values down to ~2ms
and ~1ms respectively. I've only found this useful with old/half-assed
code that polls interfaces. They'll use usleep() to throttle the
polling and not max out the CPU.

But that is background info, the main point is that it has no effect on
power consumption.

Do your system monitors (gkrellm, top, whatever) show a maxed out cpu?

Cooper.
--
gentoo-ppc-user [at] gentoo mailing list


ali at geschmeidomatik

Jun 29, 2005, 7:35 AM

Post #12 of 12 (1303 views)
Permalink
Re: OT: thermal management diff 2.4 vs. 2.6 [In reply to]

On Mi, Jun 29 2005 at 10:13:10 -0400, Jason Cooper wrote:
> > Now _that_ is strange: I recently changed that back from 1000 to 100 but
> > with no visible (or audible that is) effect whatsoever.
> >
>
> This is correct behavior. The value of HZ defines the minimum
> resolution of system calls like usleep() and select(). At 100Hz, the
> minimum resolution is ~20ms (= 2 * 1 / f) for usleep and ~10ms (= 1 / f)
> for select(). Setting it to 1000Hz adjusts those values down to ~2ms
> and ~1ms respectively. I've only found this useful with old/half-assed
> code that polls interfaces. They'll use usleep() to throttle the
> polling and not max out the CPU.
>
> But that is background info, the main point is that it has no effect on
> power consumption.
>
> Do your system monitors (gkrellm, top, whatever) show a maxed out cpu?

Nope. There's no indication that there is anything going on. The system
load is flat at 0.00 and the cpu seems to be idle according to top.
Also i tried to stop all daemons (even those i'd rather not turn off
under every-day circumstances) so that there is hardly more than init
and a few getties running (not even X) and still the fan would go off
after a few minutes and never stop 'til i shut down the computer.

Alexander

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