powertop doesn't show any stats

[Tixy (Jon Medhurst)]

When testing the 13.10 linux-linaro release on vexpress [1] I find that running powertop doesn't show any kind of statistics appart from a brief note about Network interface: eth0. This occurs on both TC2 and the A9 CoreTiles.

Powertop does work on the the 13.10 LSK release, so there problem may be difference between kernel versions 3.12-rc5 vs 3.10, or IKP vs big.LITTLE MP.

[1] https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-13.10-release/#build=2

[Tixy (Jon Medhurst) (tixy)]

I tried experimenting with a few combinations of components from the 13.10 release showing this bug and the 13.09 release which doesn't...

- The 13.10 powertop works on a 13.09 image
- The 13.09 powertop fails on a 13.10 image
- The 13.09 kernel (Linux 3.11) used with the 13.10 image makes powertop work.
- The 13.10 kernel (Linux 3.12-rc5) used with the 13.109 image makes powertop fail.

So the failures occur with either of the versions of powertop when run on the latest 3.12-rc5 based kernel.

I compared the kernel configs between the two kernel versions and the minor differences don't look like they should impact powertop.

My best guess is that some API or config default has changed in 13.12 and broke powertop..

[Tixy (Jon Medhurst) (tixy)]

My previous comment said "...API or config default has changed in 13.12 and broke powertop.." this should have said '3.12', as in the Linux version number.

[Tixy (Jon Medhurst) (tixy)]

Bug still present running on Linux 3.13 based kernels as used by the Linaro 13.12 release...
https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-13.12-release/#build=1

[Tixy (Jon Medhurst) (tixy)]

Bug still present running on Linux 3.13 based kernels as used by the Linaro 14.01 release...
https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.01-release/#build=6

(This comment corrects the URL which is in comment #4)

[Tixy (Jon Medhurst) (tixy)]

Bug still present in the Linaro 14.02 release...
https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.02-release/#build=11

[Tixy (Jon Medhurst) (tixy)]

Bug still present in the Linaro 14.03 release...
https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.03-release/#build=1

[Tixy (Jon Medhurst) (tixy)]

Bug still present in the Linaro 14.04 release...
https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.04-release/#build=1

[sanjay singh rawat (sanjay-rawat)]

Checked on Panda android 13.10 (kitkat). I can see the info in powertop. This seems to be specific to vexpress.

[Tixy (Jon Medhurst) (tixy)]

On Thu, 2014-04-24 at 12:50 +0000, sanjay singh rawat wrote:
> Checked on Panda android 13.10 (kitkat). I can see the info in powertop.
> This seems to be specific to vexpress.

PandaBoard is not being maintained and is stuck on some very old kernel
version (3.2) and as I said in comment #1 my experiments found that the
problem only started occurring with kernel version 3.12.

[sanjay singh rawat (sanjay-rawat)]

On Thursday 24 April 2014 07:43 PM, Tixy (Jon Medhurst) wrote:
> On Thu, 2014-04-24 at 12:50 +0000, sanjay singh rawat wrote:
>> Checked on Panda android 13.10 (kitkat). I can see the info in powertop.
>> This seems to be specific to vexpress.
>
> PandaBoard is not being maintained and is stuck on some very old kernel
> version (3.2) and as I said in comment #1 my experiments found that the
> problem only started occurring with kernel version 3.12.
>

I have one question, vexpress is a reference platform? I checked, there
is no specific vexpress cpuidle and cpufreq drivers. I tried mainline
vexpress image on qemu, i dont find any attributes for cpuidle/freq.
Hence powertop will not work.

--
sanjay

[Tixy (Jon Medhurst) (tixy)]

On Tue, 2014-04-29 at 06:30 +0000, sanjay singh rawat wrote:
> On Thursday 24 April 2014 07:43 PM, Tixy (Jon Medhurst) wrote:
> > On Thu, 2014-04-24 at 12:50 +0000, sanjay singh rawat wrote:
> >> Checked on Panda android 13.10 (kitkat). I can see the info in powertop.
> >> This seems to be specific to vexpress.
> >
> > PandaBoard is not being maintained and is stuck on some very old kernel
> > version (3.2) and as I said in comment #1 my experiments found that the
> > problem only started occurring with kernel version 3.12.
> >
>
> I have one question, vexpress is a reference platform? I checked, there
> is no specific vexpress cpuidle and cpufreq drivers. I tried mainline
> vexpress image on qemu, i dont find any attributes for cpuidle/freq.
> Hence powertop will not work.

Not if you use QEMU, no, but if you use the right kernel config on real
Versatile Express hardware with a TC2 CoreTile plugged in, then it does
have a working cpufreq and cpuidle. This is the main reference platform
for testing LSK, and is also used with the mainline linux-linaro
kernels.

As I said in comment #1, powertop was working fine with Linux 3.11, it
stopped working in 3.12. And the only reason it was working in 3.11 is
because I fixed powertop last time it was broken by kernel API changes
remember? See bug #1042755 "TC2: powertop doesn't show correct frequency
stats."

Unfortunately, looking at Linaro's Android builds, it's not apparent if
there are other platforms using recent kernel versions that have
hardware easily available for testing on. (Arndale is on 3.9, and I
don't know about HiSilicon boards).

If powertop is meant to work on standard Linux, not just Android,
perhaps you can check out the Ubuntu PandaBoard image?
http://releases.linaro.org/14.04/ubuntu/panda

[sanjay singh rawat (sanjay-rawat)]

this patch should help to solve the problem

[Tixy (Jon Medhurst) (tixy)]

On Wed, 2014-05-28 at 05:42 +0000, sanjay singh rawat wrote:
> ** Changed in: linaro-powertop
> Status: New => Fix Committed
>

Thanks for the fix, I can verify it works on Android with a linux-linaro
based TC2 kernel. What is the process for getting this fix into the
android branch of the Android git repo [1] which is where it needs to be
for it to be included in the Android builds?

[1] http://android.git.linaro.org/gitweb/platform/external/powertop-2.0.git

[Tixy (Jon Medhurst) (tixy)]

In testing the 14.06 linux-linaro based Android release [1] on TC2 I can see that we now get lots of stats for cpufreq and 'overview', however cpuidle, whilst it lists cpus and states, has all the values as zero.

If I look in the sysfs files from commandline [2] I can see things like time changing each time I cat the file, so, at least through that interface, the kernel looks like it's providing information, though I don't if this is where powertop get's its ide stats from or somewhere else.

Should I raise a new bug for this idle issue?

[1] https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.06-release/#build=1
[2] E.g. using "cat /sys/devices/system/cpu/cpu0/cpuidle/state0/time"

[sanjay singh rawat (sanjay-rawat)]

thanks for trying Tixy. Yes please raise a bug for the cpuidle case.

On Monday 23 June 2014 07:34 PM, Tixy (Jon Medhurst) wrote:
> In testing the 14.06 linux-linaro based Android release [1] on TC2 I can
> see that we now get lots of stats for cpufreq and 'overview', however
> cpuidle, whilst it lists cpus and states, has all the values as zero.
>
> If I look in the sysfs files from commandline [2] I can see things like
> time changing each time I cat the file, so, at least through that
> interface, the kernel looks like it's providing information, though I
> don't if this is where powertop get's its ide stats from or somewhere
> else.
>
> Should I raise a new bug for this idle issue?
>
> [1] https://android-build.linaro.org/builds/~linaro-android/vexpress-linaro-14.06-release/#build=1
> [2] E.g. using "cat /sys/devices/system/cpu/cpu0/cpuidle/state0/time"
>

--
sanjay

[Tixy (Jon Medhurst) (tixy)]

New bug raised for the cpuidle issue mentioned in comment #15 ... https://bugs.linaro.org/show_bug.cgi?id=55