powertop

scooby · 2009-12-07 17:09:03

I have custom compiled my kernel, everything built in, works ok.

I am running powertop to try and extend battery life, and it tells me to enable CONFIG_NO_HZ, CONFIG_HPET_TIMER, CONFIG_USB_SUSPEND, CONFIG_ACPI_BATTERY. All these options are enabled in my .config and kernel, but powertop is suggesting they are not.

I have recompiled the kernel several times trying to fix this, it is like powertop is not seeing what I have configured and compiled in to the kernel.

Anyone any ideas?

.:B:. · 2009-12-07 17:22:56

I know for USB suspend you need to enable it, not just compile it in. It's not because the kernel can use it that it will do so in its default configuration.

scooby · 2009-12-07 17:56:07

Yes, you are correct.

However, for the other CONFIG..., I think that they are compiled in.

Just done some tests with the stock arch kernel, powertop doesn't complain about enabling CONFIG_NO_HZ etc.
Noticed that the wakeups were about 35-40, as opposed to my custom kernel where they are about 150
Also, hrtimer_start_range_ns are about 140 with my custom kernel, as opposed to about 30 with the stock kernel.

I think it is a compilation problem, I will disable ccache and start kernel compiling all over again.

Good news is that with the custom kernel, powerdraw is about 11W, it's about 15 with the stock kernel.

.:B:. · 2009-12-07 18:03:16

If you're unsure, and if you have your config in /proc/config, you can still grep for the configuration options powertop is complaining about. You might be right though - I have run tests with powertop too, and it will often suggest to use a hotkey to turn off X or Y, which you press, only to have it make the same remark a few minutes later...

scooby · 2009-12-07 20:16:05

My new kernel is now behaving itself with respect to powertop. I disabled ccache, did make mrproper, configured away, and it now behaves as it should. Powertop has stopped complaining about CONFIG_NO_HZ and other CONFIG not being enabled, when they are.

I would say I have something set up wrong, as I think you should be able to use ccache with kernel compilation.
Finetuning kernel compilation is a pita without ccache.

scooby · 2009-12-09 18:47:23

Ok, finally worked this out. Nothing to do with ccache.

I have to enable kernel .config support, and access to .config through /proc/config.gz, in menuconfig.

Oh well, there's another thing I have learned. Now to streamline my kernel...

Arch Linux

#1 2009-12-07 17:09:03

powertop

#2 2009-12-07 17:22:56

Re: powertop

#3 2009-12-07 17:56:07

Re: powertop

#4 2009-12-07 18:03:16

Re: powertop

#5 2009-12-07 20:16:05

Re: powertop

#6 2009-12-09 18:47:23

Re: powertop

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