Kernel 3.13 series: CPU frequency scaling

The kernel 3.13 series regulates the CPU frequency dynamically.

Quote:

CPU frequency scaling enables the operating system to scale the CPU frequency up or down in order to save power. CPU frequencies can be scaled automatically depending on the system load, in response to ACPI events, or manually by userspace programs. CPU frequency scaling is implemented in Linux kernel, the infrastructure is called cpufreq.

You can set the CPU frequency with the applet "indicator-cpufreq" for the panel.



Kernel 3.15

I have fantastic news for you!

Darren has created a new patch for the kernel 3.15 and he has compiled the kernel 3.15.6. It boots without any problems. Thanks Darren.



We'll test the new kernel before we upload it.

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@xeno74

I am very interested in energy consumption, including frequency scaling. There are some points in your message for which I need clarification :

1. Even with snapshots, I don't understand the difference between both versions here. What was Darren's patch for?

2. The cpufreq mechanism is much older than kernel 3.13. Was it broken in Linux 3.13 and restored in 3.15? Broken on X1000 prior to 3.13 and working at this version?

3. Do we have to dissociate both paragraphs, on Linux 3.13 and 3.15? I realize maybe there are 2 information communicated here.

This is the kind of topic that is motivating for me to join the effort making my Linux setup.

Did anyone measure the consumption of the X1000 at variousfrequencies?

@corto

1. Darren's patch is for the kernel 3.15.
2. It's new for the latest 3.13 kernels and Darren's kernel 3.15. The Kernel 3.14 doesn't have this feature.
3. You're right. There are 2 news.

I have uploaded the new kernel.

Download: linux-3.15.6_AmigaOne_X1000.tar.bz2

Rgds,

Christian

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Hi All,

I have compiled the kernel 3.15.8 with KVM-PR support.

Download: vmlinux-3.15.8-KVM-PR-FTRACE-AmigaOneX1000.tar.bz2



Sometimes, the automatic kernel CPU frequency regulator doesn't work exactly. For example SuperTuxKart. This game needs much CPU power but the kernel regulates the CPU frequency not to often to the highest rate. Thus the frame rate drops in STK.

In this case you have to regulate the CPU frequency to 1.8GHz with MATE's CPU Frequency Scaling Monitor or with Lubuntu's indicator-cpufreq.

Installation instructions for MATE's CPU Frequency Scaling Monitor

1. Install the package mate-applets

Quote:

apt-get install mate-applets

2. To add CPU Frequency Scaling Monitor to a panel, right-click on the panel to open the panel popup menu, then choose Add to Panel ▸ CPU Frequency Scaling Monitor.

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The kernel 3.15.10 is available. This is the last kernel of the 3.15 series (EOL).

New:

- Removed CPU frequency scaling support

Other changes:

ChangeLog-3.15.10
ChangeLog-3.15.9

It also includes:

- KVM_BOOK3S_64_PR

Support running guest kernels in virtual machines on processors
without using hypervisor mode in the host, by running the
guest in user mode (problem state) and emulating all
privileged instructions and registers.

This is not as fast as using hypervisor mode, but works on
machines where hypervisor mode is not available or not usable,
and can emulate processors that are different from the host
processor, including emulating 32-bit processors on a 64-bit
host.

- 3dfx Voodoo graphics card support
- Network support for AROS hosted
- Support for 4 serial ports
- Bluetooth USB dongle support
- Kernel tracing with ftrace
- Linux kernel icon for OS4.1 by Tommysammy[/list]

Download: vmlinux-3.15.10-KVM-PR-FTRACE-AmigaOneX1000.tar.bz2

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www.amigalinux.org

@xeno74

Quote:

xeno74 wrote: The kernel 3.15.10 is available. This is the last kernel of the 3.15 series (EOL). New: - Removed CPU frequency scaling support

Why was it disabled?

Any chance to see a Docky (with arexx interface) or similar for OS4?

Should be absolutely trivial (manual setting that is) for someone with the right docs.

I would like this as an alternative to sleep/hibernation that AmigaOS lacks. Then I could script something together with the screen blanker that lowers CPU freq to minumum and switches off the disks

Last edited by Deniil715 on 18-Aug-2014 at 07:58 AM.

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- Don't get fooled by my avatar, I'm not like that (anymore, mostly... maybe only sometimes)
> Amiga Classic and OS4 developer for OnyxSoft.

@Deniil715

Quote:

Deniil715 wrote: Any chance to see a Docky (with arexx interface) or similar for OS4? Should be absolutely trivial (manual setting that is) for someone with the right docs. I would like this as an alternative to sleep/hibernation that AmigaOS lacks. Then I could script something together with the screen blanker that lowers CPU freq to minumum and switches off the disks

On Sam440, I use a tool from m3x to change the CPU and bus frequencies (even if that has almost no impact on consumption).

About what you want, I would say that the management of cpu frequency could be manual (like the Linux cpufreq governor named "userspace") but would have more potential if controlled by the system itself, in a global power management strategy.

I am really interested in this topics and I really would like to work on that in the system (and first looking at how it is supported by Linux on the X1000).