system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

[Florian Engelhardt]

Hello,

first of all, sorry for the long headline.
second:
Every time, i try to do the following:
cat /proc/acpi/thermal_zone/THRM/temperature
the whole system looks up for a short period of time (something about
0.5s). realy everything, video and audio encoding, mouse and keyboard
input, firefox playing a flash animation, ...
I am also getting the following:
Losing some ticks... checking if CPU frequency changed.

maybe these two things are belonging to each other.

I am using a 2.6.12-rc3-mm1 kernel on a amd64 with a nvidia nforce4
mainboard.


kind regards

flo

-- 
"I may have invented it, but Bill made it famous"
David Bradley, who invented the (in)famous ctrl-alt-del key combination

Re: system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

[Andrew Morton]

Florian Engelhardt <flo@dotbox.org> wrote:
>
> Hello,
> 
> first of all, sorry for the long headline.
> second:
> Every time, i try to do the following:
> cat /proc/acpi/thermal_zone/THRM/temperature
> the whole system looks up for a short period of time (something about
> 0.5s). realy everything, video and audio encoding, mouse and keyboard
> input, firefox playing a flash animation, ...
> I am also getting the following:
> Losing some ticks... checking if CPU frequency changed.
> 
> maybe these two things are belonging to each other.
> 
> I am using a 2.6.12-rc3-mm1 kernel on a amd64 with a nvidia nforce4
> mainboard.

It might help if you were to generate a kernel profile:

readprofile -r
for i in $(seq 10)
do
	cat /proc/acpi/thermal_zone/THRM/temperature
done
readprofile -n -v -m /boot/System.map | sort -n +2 | tail -40

Re: system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

[Florian Engelhardt]

Hello,

On Wed, 27 Jul 2005 16:16:05 -0700
Andrew Morton <akpm@osdl.org> wrote:

> Florian Engelhardt <flo@dotbox.org> wrote:
> >
> > Hello,
> > 
> > first of all, sorry for the long headline.
> > second:
> > Every time, i try to do the following:
> > cat /proc/acpi/thermal_zone/THRM/temperature
> > the whole system looks up for a short period of time (something
> > about 0.5s). realy everything, video and audio encoding, mouse and
> > keyboard input, firefox playing a flash animation, ...
> > I am also getting the following:
> > Losing some ticks... checking if CPU frequency changed.
> > 
> > maybe these two things are belonging to each other.
> > 
> > I am using a 2.6.12-rc3-mm1 kernel on a amd64 with a nvidia nforce4
> > mainboard.
> 
> It might help if you were to generate a kernel profile:
> 
> readprofile -r

returns:
/proc/profile: No such file or directory

do i have to activate something special during kernel configuration?

btw: i saw that mm2 is available. Are there any changes in it, which
could solve this problem?

flo

> for i in $(seq 10)
> do
> 	cat /proc/acpi/thermal_zone/THRM/temperature
> done
> readprofile -n -v -m /boot/System.map | sort -n +2 | tail -40
> 
> 


-- 
"I may have invented it, but Bill made it famous"
David Bradley, who invented the (in)famous ctrl-alt-del key combination

Re: system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

[Andrew Morton]

Florian Engelhardt <flo@dotbox.org> wrote:
>
> Hello,
> 
> On Wed, 27 Jul 2005 16:16:05 -0700
> Andrew Morton <akpm@osdl.org> wrote:
> 
> > Florian Engelhardt <flo@dotbox.org> wrote:
> > >
> > > Hello,
> > > 
> > > first of all, sorry for the long headline.
> > > second:
> > > Every time, i try to do the following:
> > > cat /proc/acpi/thermal_zone/THRM/temperature
> > > the whole system looks up for a short period of time (something
> > > about 0.5s). realy everything, video and audio encoding, mouse and
> > > keyboard input, firefox playing a flash animation, ...
> > > I am also getting the following:
> > > Losing some ticks... checking if CPU frequency changed.
> > > 
> > > maybe these two things are belonging to each other.
> > > 
> > > I am using a 2.6.12-rc3-mm1 kernel on a amd64 with a nvidia nforce4
> > > mainboard.
> > 
> > It might help if you were to generate a kernel profile:
> > 
> > readprofile -r
> 
> returns:
> /proc/profile: No such file or directory
> 
> do i have to activate something special during kernel configuration?

Set CONFIG_PROFILING=y

> btw: i saw that mm2 is available. Are there any changes in it, which
> could solve this problem?

Well there's a huge ACPI patch in there, but I cannot say whether it
addresses this problem.

Re: [ACPI] Re: system freezes for 0.2 to 0.5 seconds when reading /proc/acpi/thermal_zone/THRM/temperature

[Sanjoy Mahajan]

I get the same short freezes with

  cat /proc/acpi/battery/*/{state,info}

and also with the 'acpi' command-line tool.  I'm about to try the the
suggested kernel profiling with -mm3 and will report the results.

Meanwhile:

>>> readprofile -r
>> do i have to activate something special during kernel configuration?
>Set CONFIG_PROFILING=y

That confuses me.  For readprofile support,
Documentation/basic_profiling.txt says

  Add "profile=2" to the kernel command line.

For Oprofile support it says:

  Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y

The two together suggest that CONFIG_PROFILING shouldn't be needed for
readprofile.

-Sanjoy